EOC
2012-2013
Biology 1 (Regular & Honors)
Study Guide
1
Table of Contents
Table of Contents................................................................................................................................................... 2
EOC Exam Information ........................................................................................................................................... 3
Standards Review .................................................................................................................................................. 4
Florida Standard 1: The Practice of Science ..............................................................................................................4
Florida Standard 2: The Characteristics of Scientific Knowledge ..............................................................................5
Florida Standard 3: The Role of Theories, Laws, Hypotheses, and Models ...............................................................6
Florida Standard 14: Organization and Development of Living Organisms ..............................................................6
Florida Standard 15: Diversity and Evolution of Living Organisms .........................................................................16
Florida Standard 16: Heredity and Reproduction ...................................................................................................24
Florida Standard17: Interdependence....................................................................................................................41
Florida Standard 18: Matter and Energy Transformations .....................................................................................51
Vocabulary........................................................................................................................................................... 60
Answering Test Questions ................................................................................................................................... 71
Works Cited ......................................................................................................................................................... 72
2
EOC Exam Information
CATEGORY
Exam Date:
Number of Questions:
Time limit:
Accessories
Method of Testing:
Scoring:
Other:
Question Distribution (Approx.):
More Information:
DETAILS
Begins Friday, May 3, 2013
Up to 66 (some are experimental)
160 minutes is allotted, but you may continue working
after the time limit until the end of the day
Four Function Calculator
Periodic Table of the Elements
Computer based testing on ePAT
325 (1) - 475 (5)
Graduation requirement
Molecular and Cellular Biology (35%)
Organisms, Populations, and Ecosystems (40%)
Classification, Heredity, and Evolution (25%)
http://fcat.fldoe.org/eoc/pdf/Biology1EOCFactSheet201213.pdf
http://fcat.fldoe.org/eoc/pdf/BiologyFL11Sp.pdf
3
Standards Review
Florida Standard 1: The Practice of Science
This section as well as the next two is based on basic scientific processes in general. If you would like a more detailed review on specifically
biology and you feel comfortable with the following standards, then you can just skip to the section titled “Organization and Development of Living Organisms.”
In order to master this standard, you must understand that:
Scientific inquiry is a multifaceted activity; The processes of science include the formulation of scientifically investigable questions,
construction of investigations into those questions, the collection of appropriate data, the evaluation of the meaning of those data,
and the communication of this evaluation.
The processes of science frequently do not correspond to the traditional portrayal of "the scientific method."
Scientific argumentation is a necessary part of scientific inquiry and plays an important role in the generation and validation of
scientific knowledge.
Scientific knowledge is based on observation and inference; it is important to recognize that these are very different things. Not
only does science require creativity in its methods and processes, but also in its questions and explanations.
SC.912.N.1.1
Objective: Define a problem based on a specific body of knowledge
You will need to know how to:
Pose questions about the natural world
Conduct systematic observations
Examine books and other sources of information to see what is already known
Review what is known in light of empirical evidence
Plan investigations
Use tools to gather, analyze, and interpret data
Pose answers, explanations, or descriptions of events
Generate explanations that explicate or describe natural phenomena
Use appropriate evidence and reasoning to justify these explanations to others
Communicate the results of scientific investigations
Evaluate the merits of the explanations produced by others
It is important to understand that these processes will be used in combination with other standards and include content from those standards.
This will not be tested alone. For example, a question may ask what you can infer by using a data table about a specific biological process from
another standard.
You will need to know how to interpret graphs as well.
Also, you may be asked to identify parts of different types of microscopes, including compound, scanning electron, dissecting, and transmission
electron microscopes.
SC.912.N.1.2
Objective: Describe and explain what characterizes science and its methods.
Science is characterized by empirical observations, testable questions, formation of hypotheses, and experimentation that results in stable and
replicable results, logical reasoning, and coherent theoretical constructs. Pseudoscience does not fit into this category, nor does religion or any
other opinion or subjective observation.
SC.912.N.1.3
Objective: Recognize that the strength or usefulness of a scientific claim is evaluated through scientific argumentation, which depends on
critical and logical thinking, and the active consideration of alternative scientific explanations to explain the data presented.
You may be asked to identify why the results of a scientific investigation are unreliable or biased in some way, such as sources of error or
uncontrolled conditions. For example:
Jim wanted to see how the amount of sunlight influences the height of a plant. He set up an experiment in which 5 plants got a large amount of
sunlight and 5 plants were left in a dark room. He gave one set of plants two cups of water each day and another set 1 cup each day? Why
might his results be rejected by the scientific community?
The answer is that he used multiple test variables. In a scientific investigation, only one variable may be changed. All other variables must
remain constant. The reason for this is so that when analyzing the results of an investigation, a scientist can determine the exact cause with a
high level of certainty as to why the results are what they are.
4
SC.912.N.1.4
Objective: Identify sources of information and assess their reliability according to the strict standards of scientific investigation.
This standard means that you must determine why a source of scientific information is or is not reliable. In science, some sources are not
appropriate for obtaining information.
Sources considered as unreliable may include but are not limited to:
Forums, wikis, and blogs
Personal websites
Sources considered as reliable may include but are not limited to:
Scientific journals
College and University web sites
Government-funded web sites such as NASA
The question may ask you to identify the source that is the most or least reliable.
SC.912.N.1.5
Objective: Describe and provide examples of how similar investigations conducted in many parts of the world have resulted in the same
outcome.
You should understand that contributions to science are made by people all over the world. For example, the ideas and contributions of several
scientists were necessary to our understanding of evolution today, even though some of them may have been incorrect.
Some scientists necessary for this to happen included:
James Hutton’s Theory of Geological Change
Charles Lyell’s belief that the Earth changes over large periods of time
Lamarck’s hypothesis that organisms become more complex and perfect, and believed in use and disuse
Thomas Malthus believed that if a population grew unchecked, the population would outgrow the food supply and a majority of
offspring would die.
These scientists shaped Charles Darwin’s thinking about evolution, even though Lamarck’s ideas are considered incorrect. He applied their ideas
to his theory on evolution. Darwin’s theory is the generally accepted theory today throughout the scientific community.
SC.912.N.1.6
Objective: Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied.
This means that you should be able to draw a conclusion from information given. You need to analyze the graph and the ask yourself questions
like:
Is there a pattern or correlation in the data?
What biological process is being demonstrated?
What is the relationship between data sets and why is that the relationship?
Florida Standard 2: The Characteristics of Scientific Knowledge
Scientific knowledge is based on empirical evidence, and is appropriate for understanding the natural world, but it provides only a
limited understanding of the supernatural, aesthetic, or other ways of knowing, such as art, philosophy, or religion.
Scientific knowledge is durable and robust, but open to change.
Because science is based on empirical evidence it strives for objectivity, but as it is a human endeavor the processes, methods, and
knowledge of science include subjectivity, as well as creativity and discovery.
SC.912.N.2.1
Objective: Identify what is science, what clearly is not science, and what superficially resembles science (but fails to meet the criteria for
science).
You need to realize that science is the organized and systematic inquiry that is derived from observation and experimentation that can be
verified and tested by further experimentation. For example, subjective observations, such as opinions and beliefs, are not included as a part of
science. Opinions and beliefs are excluded from any analyses of scientific investigations. Concepts such as religion are not considered scientific
because it does not qualify as testable, and as a result, is also left separated from science.
SC.912.N.2.2
Objective: Identify which questions can be answered through science and which are outside the boundaries of scientific investigation, such as
questions addressed by other ways of knowing, such as religion and philosophy.
You will need to identify scientific questions that can be proved or disproved by scientific testing and experimentation.
Pseudoscience is a claim or belief that is presented as scientific but lacks supporting evidence of plausibility. A recent example of pseudoscience
is the 2012 doomsday belief. Although it is presented as scientific, it lacks supporting evidence to prove or disprove it. Pseudoscience is not a
science, nor does it adhere to its strict standards.
5
Florida Standard 3: The Role of Theories, Laws, Hypotheses, and Models
The terms that describe examples of scientific knowledge, for example: "theory," "law," "hypothesis" and "model" have very specific meanings
and functions within science.
SC.912.N.3.1
Objective: Explain that a scientific theory is the culmination of many scientific investigations drawing together all the current evidence
concerning a substantial range of phenomena; thus a scientific theory represents the most powerful explanation have to offer.
A theory is a well-tested hypothesis supported by a preponderance (superiority in numbers or amount) of empirical evidence and proposes an
explanation for a wide range of observations and experimental results. An example is the theory of natural selection. It is supported by a large
amount of data and explains many observations of life on Earth.
It is important to note that a theory can change and they may be refuted. Before natural selection, many people believed that all organisms on
Earth were put there by God and never change. Nowadays, we understand that this is not true, and the theory of Natural Selection is the most
supported theory by the scientific community.
SC.912.N.3.4
Objective: Recognize that theories do not become laws, nor do laws become theories; theories are well supported explanations and laws are
well supported hypotheses.
Theories explain why something happens, while laws explain what happens under a given set of conditions.
SC.912.N.3.5
Objective: Describe the function of models in science, and identify the wide range of models used in science.
In biology, most complex systems are modeled on computers.
Florida Standard 14: Organization and Development of Living Organisms
Standards 4 - 13 have little significance in biology are NOT topics that will appear on the EOC. The remaining standards from 14 - 18 WILL
appear on the EOC. The other standards relate to other courses such as Earth/Space, Chemistry, etc.
Here are the standards for Florida Standard 14:
Cells have characteristic structures and functions that make them distinctive.
Processes in a cell can be classified broadly as growth, maintenance, reproduction, and homeostasis.
Life can be organized in a functional and structural hierarchy ranging from cells to the biosphere.
Most multicellular organisms are composed of organ systems whose structures reflect their particular function.
SC.912.L.14.1
Objective: Describe the cell theory and relate the history of its discovery to the process of science.
The cell was first discovered by English scientist Robert Hooke while examining cork cells. He called them cells because they looked like
monastery cells. He was looking at dead plants with cell walls and empty space.
Anton Van Leeuwenhoek created a microscope much more powerful than Hooke’s compound microscope. He was the first to describe living
cells in pond water.
The cell theory was created by Schleiden, Schwann, and Virchow, each working independently to create a different aspect of the cell theory.
The cell theory states:
All organisms are made of cells.
All existing cells are produced by other living cells.
The cell is the most basic unit of life.
The history of the cell theory relates to the process of science because it involves new ideas building and improving upon older ideas.
You do NOT need to know what each individual scientist contributed to the cell theory.
SC.912.L.14.2
Objective: Relate structure to function for the components of plant and animal cells. Explain the role of cell membranes as a highly selective
barrier (passive and active transport).
Eukaryotic cells have a cytoskeleton. Its structure is a network of proteins that changes to meet the needs of the cell. The cytoskeleton is
composed of:
Microtubules - act as guides for the movement of organelles; maintains cell shape
Intermediate filaments - gives the cell strength
Microfilaments - helps the cell move and divide
The main function of the cytoskeleton is to support and shape the cell, which is achieved by using all three components working together.
6
Cytoplasm fills the space between organelles, consisting of cytosol and water. The makeup of cytoplasm demonstrates the importance of water
to the cell structure. Water acts as an important solvent in chemical reactions, allowing many chemical reactions to occur.
The nucleus stores DNA. The nucleus contains DNA enclosed in the nuclear envelope. The structure of the nuclear envelope contains pores in
them, allowing large molecules to move back and forth. The nucleus also contains the nucleolus, where ribosomes are made. The structure of
the nucleus allows for:
Protection of DNA from harmful materials
Maintaining the availability of DNA for use
The endoplasmic reticulum is an interconnected network of folded membranes. The ER is folded to form a maze of enclosed spaces, maximizing
surface area for processes such as production of proteins and lipids, in the lumen, the interior of the maze. The folding of the ER allows it to fit
within the cell and maximize space for life processes.
The rough ER contains ribosomes attached to it, where proteins are made.
The smooth ER makes lipids as well as breaks down drugs and alcohol.
Ribosomes are organelles that link together amino acids to form proteins. They are both active participants and the site of protein synthesis.
They are assembled in the nucleolus, pass through the nuclear pores, and travel into the cytoplasm. They have 3 binding sites where mRNA can
attach and help create a protein.
The Golgi apparatus consists of closely layered stacks of spaces that process, sort, and deliver spaces. The membranes may have enzymes that
may make changes to proteins. The proteins may be stored or transported to other parts of the cell.
Vesicles are small membrane - bound sacs that divide some material from the rest of the cytoplasm and transport materials within the cell.
After a protein is made, part of the ER forms a vesicle around the protein, which can then travel to the Golgi complex.
The mitochondria supplies energy to the cell. Its inner membranes increase the surface area, allowing more ATP to be produced. They have
their own ribosomes and DNA.
A vacuole is a fluid-filled sac for storage of materials, including water, food, and enzymes. Most animal cells have small vacuoles, but plant cells
have a large central vacuole.
A lysosome is a membrane-bound organelle that contains digestive enzymes. These digestive enzymes can break down bacteria and recycle
worn out cell parts. They are found mostly in animal cells, but do exist in plant cells. The enzymes (which are proteins) are made in the ER and
then activated in the Golgi body. Their enclosed membranes prevent them from destroying necessary structures.
The centrosome is a small region of cytoplasm that produces microtubules. It contains two centrioles in animal cells. Microtubules grow from
the centrioles and become spindle fibers. They are not found in plants except for algae.
The cell wall in plant cells protects, supports, and shapes the cell. Cell walls can be made up of various molecules according to the needs of the
organism.
Chloroplasts, found in plant cells, carry out photosynthesis. They have thylakoid disk-shaped structures that contain chlorophyll and allow for
photosynthesis to take place. They can be found in organisms other than plants.
The cell membrane forms a boundary between the cell and the outside environment and controls the passage of materials into and out of a
cell. It is composed of a double layer phospholipid. The fluid mosaic model is used to describe the characteristics of the cell membrane. It
explains that:
The two layers of phospholipids can slide past each other.
The cell membrane has other molecules embedded in them.
These other molecules can be:
Cholesterol, which strengthens the cell membrane
Certain proteins, which perform a variety of functions
Carbohydrates, which help cells distinguish the type of cell
The cell membrane is selectively permeable, allowing only some materials to pass through, allowing the cell to maintain homeostasis.
Molecules can cross the cell membrane in one of several ways, depending on the type of molecule.
Diffusion, the movement of molecules from a region of higher concentration to that of a lower concentration
Osmosis, the diffusion of water through the cell membrane (and specifically water)
Facilitated diffusion, by which a large molecule can cross through a protein channel.
Pumps, which moves molecules from lower concentration to higher concentration
Endocytosis, which involves engulfing a substance in part of the cell membrane, allowing the substance to enter
Exocytosis, which involves engulfing a substance in part of the cell membrane, allowing the substance to exit
Diffusion, osmosis, and facilitated diffusion are forms of passive transport, while using pumps, endocytosis, and exocytosis are forms of active
transport. Passive transport is the process by which molecules move across a cell membrane without the use of energy from the cell. Active
transport is the process by which molecules move across a cell membrane requiring the use of the cell’s energy.
For the cell membrane, know the following:
A solution is isotonic to a cell if it has the same concentration of dissolved particles as the cell.
A solution is hypertonic to a cell if it has a higher concentration of dissolved particles as the cell.
A solution is hypotonic to a cell if it has a lower concentration of dissolved particles as the cell.
In an isotonic solution, the cell maintains its size because water moves into and out of the cell at the same rate. In a hypertonic solution, water
moves from inside the cell to outside the cell, causing it to shrivel and die. In a hypotonic solution, water enters the cell, causing it to expand or
7
burst.
SC.912.L.14.3
Objective: Compare and contrast the general structures of plant and animal cells. Compare and contrast the general structures of prokaryotic
and eukaryotic cells.
Plant cells and animal cells are both eukaryotic cells. Both types of cells contain:
Cytoskeleton
Vesicle
Nucleus
Nucleolus
Endoplasmic Reticulum
Ribosome
Centrosome
Cell membrane
Golgi apparatus
Mitochondrion
Small vacuoles
This means that both plant and animal cells must perform most of the same cellular processes to survive. However, plant cells have
chloroplasts, a large central vacuole, and a cell wall. This gives plant cells rigid shapes with extra storage space for water and food as well as a
greenish color due to the presence of chlorophyll. In animal cells, a centriole and a lysosome are found. Animal cells are generally irregularly
shaped and do not have a greenish color.
Both eukaryotes and prokaryotes must both perform basic life functions to survive. The most important differing characteristic is that
eukaryotes contain a nucleus while prokaryotes do not, even though they both have DNA. Eukaryotic cells contain membrane-bound organelles
while prokaryotes do not.
SC.912.L.14.4
Objective: Compare and contrast structure and function of various types of microscopes.
A microscope provides an enlarged image of an object
Microscopes are instrumental in the history of the study of biology.
A compound light microscope magnifies objects using lenses, used to see living or preserved specimens.
Electron microscopes use beams of electrons to magnify objects, which can produce much higher magnifications than light microscopes.
However, the test specimens must be studied in a vacuum and therefore nonliving. Two types of electron microscopes are:
Scanning electron (SEM) - scans the surface of a specimen with a beam of electrons. The specimen is coated in a layer of metal, and
a computer colorizes the three dimensional image.
Transmission electron (TEM) - transmits an electron through a thin slice of specimen. It makes a 2-D image like that of a light
microscope at a higher resolution.
SC.912.L.14.5
Objective: Explain the evidence supporting the scientific theory of the origin of eukaryotic cells (endosymbiosis).
The fossil records show that eukaryotes may have evolved 1.5 billion years ago. The first eukaryotes were unicellular. Today, all cells in
multicellular organisms are eukaryotes.
Endosymbiosis is a relationship in which one organism lives within the body of another, and both benefit in the relationship.
The theory of endosymbiosis says that:
Early mitochondria and chloroplasts were simple prokaryotes.
Some smaller prokaryotes may have survived in larger ones rather than being digested.
Early cells that took in a primitive mitochondria had more ATP.
Early cells that took in a primitive chloroplast could photosynthesize.
Primitive mitochondria and prokaryotes found a stable environment and nutrients.
Evidence for this theory:
Mitochondria and chloroplasts have their own DNA and ribosomes.
Mitochondria and chloroplasts are about the same size as prokaryotes.
Mitochondrial and chloroplast DNA forms a circle, and gene structures resemble a prokaryote.
SC.912.L.14.6
Objective: Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspectives of both
individual and public health.
Germ theory states that pathogens cause disease.
A pathogen is any living organism or particle that causes disease. Pathogens include viruses, fungi, some bacteria, protozoa, and parasites.
8
Pathogens can enter the body via direct or indirect contact.
Through the placenta
Transmission of HIV through sexual intercourse
Indirect contact on everyday surfaces
Through the air and water
By other organisms, called vectors
A virus is an infectious particle made only of a strand of DNA or RNA surrounded by a protein coat. Viruses are not considered alive because
they cannot reproduce on their own. A viroid is an infectious particle that causes disease in plants. A prion is an infectious particle made only of
proteins that cause other proteins to fold incorrectly. Prions are infectious, yet have no genetic material. Prion diseases are always fatal
because the body has no immune response against a protein.
Viruses cause diseases in many organisms. An example is the common cold.
An epidemic is a rapid outbreak of an infection that affects many people. In the U.S., up to 20% percent is infected with the flu epidemic
annually.
A vaccine is a substance that stimulates the body’s own immune response against invasion by microbes. A vaccine is made from a weakened or
dead pathogen. It works by allowing the body to produce memory cells in preparation for a future attack.
A retrovirus Is a virus that contains RNA and uses an enzyme called reverse transcriptase to make a DNA copy. An example is HIV.
Bacteria can be infectious or non infectious. Bacteria that aid in digestion within the body are extremely important. In contrast, bacterial
pathogens can be extremely dangerous, causing diseases such as tuberculosis, etc. Bacteria can cause disease by disrupting homeostasis or
producing toxins, a poison released from an organism. Bacteria can be fought with antibiotics, but a risk is that bacteria evolve resistance to
antibiotics as a result of overuse, underuse, or misuse of the medication.
The environment can also cause health issues towards people. There may be chemicals in the air, toxins in the water. Air pollution has been
linked to the development of asthma. Nutritional deficiencies in starving cause parts of the world have a shorter life span and a higher death
rate. Many negative environmental factors can have many negative long-term effects, such as cancer, cardiovascular disease, respiratory
disease, and a decline in overall health.
Genetic health factors usually occur on an individual level. Most genetic health factors arise from mutations. A mutation in a gamete can impair
an organism for its entire life or even kill the organism. Mutations can also cause cancer in cells. Depending on the type of cancer, the severity
can vary. Cancer is the common name for a class of disease characterized by uncontrolled cell division. Cancer may be benign, meaning that
they remain clustered, or malignant, meaning that a cancer cell detaches from the tumor (or metastasize) and can start more tumors elsewhere
in the body. Carcinogens, such as tobacco smoke and certain air pollutants, promote the development of cancer. A genetic mutation can also be
beneficial. However, they may be harder to spot because they aren’t as obvious. We know about the mutations that are harmful because they
impair or kill the person. However, it isn’t obvious to know whether a mutation makes us a little faster or a little smarter.
SC.912.L.14.7
Objective: Relate the structure of each of the major plant organs and tissues to physiological processes.
A seed is a storage device for a plant embryo.
A parenchyma cell is the most common type of plant cell that stores materials for the plant, which have thin walls and large vacuoles.
Parenchyma cells are responsible for photosynthesis. They heal the plant and can indefinitely divide. They are flexible cells.
A collenchyma cell has unevenly thick and thin cell walls. They support growing plants. They are strong and flexible cells that form into strands.
A sclerenchyma cell is the strongest type of cell, hardened by lignin, which makes the plant rigid. They are found where the plant is no longer
growing. Upon reaching maturity, they die, but the cell walls remain for support.
Dermal tissue is the outer covering of a plant.
Ground tissue is tissue that supports and stores materials in the roots and stems. They are filled with chloroplasts in leaves. They consist of all
types of cells, but parenchyma is the strongest.
Vascular tissue is tissue that transports water, food, and nutrients. The two main types of tubes are xylem for transporting water and phloem
for transporting products of photosynthesis. Water moves through xylem by the cohesion-tension theory, in which water’s properties allow it to rise through a plant. Products of photosynthesis move through phloem according to the pressure-flow model, in which movement is from a
sugar source to a sugar sink.
Leaves can perform transpiration, the release of vapor through the skin or stomata of plant tissue.
Structure of a leaf:
Blade: broad and flat part of the leaf
Petiole: connects the blade to the stem
Mesophyll: tissue between the two dermal layers of a leaf
Leaf types:
Leaf type can be simple, compound, or double compound
9
Leaf veins can be parallel or pinnate
Leaf margin can be entire margin, toothed, or lobed.
The vascular cylinder is in the center of the root, made up of vascular tissue, and it transports materials from the roots.
The meristem is the part of the root where cells divide and grow. Apical meristems increase the length of the roots. Lateral meristems increase
the thickness of roots and stems.
Primary growth takes place in the apical meristem; secondary growth adds to the width in stems and roots of woody plants.
A fibrous root makes fine branches in which most roots are the same size.
A taproot has a long, thick, vertical root with smaller branches, which allows the plant to get water from deep in the ground.
Guard cells surround each stoma, which open and close, regulating the exchange of oxygen and carbon dioxide.
Parts of a flower:
Sepal: modified leaves that protect the flower
Petal: modified leaves just inside the sepals
Stamen: male structure of a flower; consisting of filaments and anthers
10
Carpel: female structure of a flower; composed of the stigma, style, and ovary
Ovary: found at the base of the ovary
Flowering plant life cycle
Pollen grains, the male gametophytes, are produced in the anthers. The ovary contains ovules, which contain the female
gametophyte. Each pollen grain has 2 cells. Gametes are formed by meiosis. Those gametes divide by meiosis. One female
gametophyte can form in each ovule. It divides by meiosis to produce four female spores. Usually, three of them die. The nucleus of
the last one dies, dividing by mitosis three times. The result is a single spore with eight nuclei. Membranes grow in to produce 7
cells, with one large central cell having two haploid nuclei. One of the other cells develops into an egg.
Pollen may be transferred from an anther to a stigma via pollination. One cell of a pollen grain divides to form 2 sperm, while the
other forms a tube down which the sperm travel. The tube extends down the style toward the ovule.
Double fertilization occurs. One sperm fertilizes the egg, which develops into an embryo. The other sperm unites with the polar
nuclei to form the endosperm, a food supply for the developing plant embryo. The cell is now a triploid nucleus. Double fertilization
occurs only in flowering plants. The outer layer of the ovule becomes a protective coat.
Many seeds develop within the ovary. The ovary tissue becomes the fruit.
Other:
Regeneration is the growing of a new individual from a fragment of a stem, leaf, or root.
Vegetative reproduction is the type of asexual reproduction in which stems, leaves, or roots attached to the parent produce new
individuals.
Dormancy is a period in which an embryo stops growing
Germination is the period in which the embryo breaks out of the seed coat and begins to grow into a sibling
SC.912.L.14.8
Objective: Explain alternation of generations in plants.
Alternation of generations is the alternation between the haploid and diploid phases of plant life.
A sporophyte is a spore producing plant. A gametophyte is a gamete-producing plant (a gamete is a sperm or egg in animals). Spores are
haploid and gametes are diploid.
Steps in alternation of generations:
A haploid gametophyte produces haploid gametes by mitosis.
Reproductive cells combine and fertilization takes place.
The cell is now a diploid zygote.
The zygote grows into a diploid sporophyte by mitosis.
The diploid sporophyte produces haploid spores by meiosis.
The spore divides into a haploid gametophyte by mitosis.
The process repeats itself.
SC.912.L.14.9
Objective: Relate the major structure of fungi to their functions.
The bodies of multicellular fungi are made up of fungi. Cytoplasm can flow through the hyphae. Underground, they group together to form a
mycelium. Mycelia may produce a fruiting body, a reproductive structure of a fungus that grows above the ground, such as a mushroom.
SC.912.14.26
Objective: Identify the major parts of the brain on diagrams or models.
This is on the EOC every year. You will need to know this.
The illustration below shows four lobes of the human brain.
11
Label 1 shows the occipital lobe.
Label 2 shows the parietal lobe.
Label 3 shows frontal lobe.
Label 4 shows the temporal lobe
This standard does not require you to know the functions of each part of the brain. However, you will need to know where the following are
located within the brain:
The cerebrum
The cerebellum
Pons
Medulla oblongata
Brain stem
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
More information on the parts of the brain:
The CNS includes the spinal cord and brain. The PNS includes nerves that communicate with the CNS.
Parts of a neuron:
12
SC.912.L.14.36
Objective: Describe the factors affecting blood flow through the cardiovascular system.
The circulatory system is the body system that transports blood and other materials.
The heart is a muscular pump that moves blood
Arteries take blood away from the heart
Veins bring blood to the heart
Capillaries allow for the diffusion of materials into and out of the cells.
Valves in the veins and heart prevent backflow of blood
Atrium: upper heart valves
Ventricles: two bottom heart chambers
Pacemaker (sinoatrial node) generates electricity that causes the heart to pump
Pulmonary circulation occurs between the heart and lungs. Systemic circulation occurs between the heart and the rest of the body.
Blood pressure is the force with which blood pushes against the wall of an artery. A healthy blood pressure is 120 over 70. Systolic pressure (the
one on top) is the pressure when the left ventricle contracts. Diastolic pressure (the one on the body) is the pressure when the left ventricle
relaxes.
Factors that affect blood flow include
Blood pressure
Blood volume
Resistance
Disease
Exercise
13
Diseases may block the heart or arteries, blocking blood flow by clogging them.
Exercise reduces the risk of cardiovascular disease.
Blood pressure is high when there are more blockages in the arteries, and low when there are fewer blockages. As the number of blockages
increases, the heart must work harder.
A higher blood volume increases blood pressure.
Higher blood viscosity slows down blood flow, while a lower blood viscosity has a higher blood flow.
SC.912.L.14.50
Objective: Describe the structure of vertebrate sensory organs. Relate structure to function in vertebrate sensory systems.
Vertebrates have a well-developed brain encased in a hard skull. They tend to be active creatures.
Endoskeleton.
Brain case that protects the brain. (cranium)
Vertebrae that protects the spinal cord.
Bones that support soft tissues and provide points for muscle attraction.
Gill arches in fish support gills.
The five classes of vertebrates are fish, amphibians, reptiles, birds, and mammals.
SC.912.L.14.52
Objective: Explain the basic functions of the immune system, including specific and nonspecific immune responses, vaccines, and antibiotics.
The immune system is the body system that fights off infections and pathogens.
Lines of defense
Skin - as a physical barrier and through sweat and oils, which are acidic and unfit for pathogenic life
Mucous membranes in openings such as the nose, ears, mouth, etc.
Immune system within the blood
A phagocyte is a cell that destroys pathogens by surrounding and engulfing them.
A T-cell destroys body cells that are infected with pathogens.
A B-cell produces proteins that inactivate pathogens that have not yet infected a body cell.
Memory cells are specialized T and B cells that provide acquired immunity because they “remember” an antigen that has previously invaded
the body, so that when they come across it again, they can quickly destroy it before you get sick again.
Antibodies are proteins made by B cells, which destroy pathogens by making the pathogen ineffective, causing them to clump and get eaten by
phagocytes, or weaken the cell membranes.
Interferons are proteins produced by body cells infected by a virus that stimulate normal cells to produce enzymes that defend the cell.
Passive immunity is immunity that occurs without the body undergoing an immune response. Active immunity is immunity that the body
produces in response to a specific pathogen that has infected or is infecting the body.
Nonspecific immune responses, such as inflammation and fever, occur in the same way to every pathogen.
Specific immune responses occur on a cellular level. They lead to acquired immunity. The body must be able to tell the difference between a
healthy cell and an infected cell in order to be effective. The body detects pathogens by their antigens, protein markers on the surface of cells
and viruses. The body uses memory cells in order to “remember” a specific antigen from a specific pathogen.
There are two types of specific immune responses:
14
A nonspecific response includes inflammation and fever. Inflammation is a nonspecific response that is characterized by swelling, pain, itching,
and increase warmth of the affected site. Fevers develop when chemicals are released that increases the body temperature, which returns to
normal after the infection is controlled and these chemicals are no longer being made.
Tissue rejection occurs when the recipient’s immune response makes antibodies against the protein markers on the donor’s tissue and potentially destroys the transplanted tissue. A special case is bone marrow transplant, which may attack the recipient, which may in turn, also
attack the transplanted tissue. This occurs because the immune system doesn’t recognize the antigens on the invading cells and regards them
as foreign pathogens.
Antibiotics are used to kill bacteria. Biotics and other antiseptics, chemicals that kill pathogens, help kill pathogens that the immune system
may have a hard time fighting off by itself.
Antiseptics are chemicals that kill pathogens outside the body.
A vaccine is a substance that contains the antigen of a pathogen, causing the immune system to create memory cells. Vaccines are substances
15
that artificially produce acquired immunity. If a pathogen enters the body and the person has been vaccinated, the person does not need to go
through the entire humoral immune response.
Leukemia is cancer of the bone marrow. It prevents the bone marrow from functioning properly by overproducing nonfunctional WBCs and
neglecting the RBCs. Therefore, neither WBCs nor RBCs are being produced. To cure this, radiation and chemo must be done to kill the cancer.
Then the transplant can occur.
An opportunistic infection is an infection caused by a pathogen that a healthy immune system would normally be able to fight off.
HIV is a retrovirus that attacks and weakens the immune system. It reproduces in T cells, and the body cannot keep up with the thousands of
new viruses that come out for each T cell that is infected.
AIDS is the final state of the immune system’s decline due to HIV. It is not a virus, but rather a condition of having a worn-out immune system.
It can lead to opportunistic infections and always results in death.
SC.912.L.14.53
Objective: Discuss basic classification and characteristics of plants. Identify bryophytes, pteridophytes, gymnosperms, and angiosperms.
A plant is a multicellular eukaryote, most of which produce food through photosynthesis and are adapted to life on land.
Some adaptations of some plants are:
Use of a cuticle to prevent water loss
Use of stomata to allow air to move into or out of the plant and to prevent water loss
Use of a vascular system to bring minerals and water to the leaves
Use of lignin to harden cell walls and ability to retain upright
Fertilization of egg within the parent, using pollen and seeds
Use of photosynthesis - in all plants
Types of mosses and seedless nonvascular plants (bryophytes) include:
Liverworts
Hornworts
Mosses - the most common nonvascular plant
Types of seedless vascular plants (pteridophytes) include:
Club mosses
Whisk ferns
Horsetails
Ferns
Types of seed plants include
Cycads
Ginkgos
Conifers
Flowering plants; which contain flowers (reproductive structure of flowering plants) and fruits (mature ovary of a flower)
Characteristics of seed-bearing plants include:
Ability to reproduce without free-standing water
Seeds nourish and protect plant embryos.
Seeds allow for dispersal of new plants.
A gymnosperm is a seed plant whose seeds are not enclosed in fruits. An angiosperm is a seed plant whose seeds are enclosed in a fruit.
Florida Standard 15: Diversity and Evolution of Living Organisms
The scientific theory of evolution is the fundamental concept underlying all of biology.
The scientific theory of evolution is supported by multiple forms of scientific evidence.
Organisms are classified based on their evolutionary history.
Natural selection is a primary mechanism leading to evolutionary change.
SC.912.L.15.1
Objective: Explain how the scientific theory of evolution is supported by the fossil record, comparative anatomy, comparative embryology,
biogeography, molecular biology, and observed evolutionary change.
The fossils support the theory of evolution because certain types of fossils are found in certain types and layers of rock. Older organisms are
found lower in the fossil record and newer organism should be found in higher layers, because as organisms die their bodies are deposited on
top of organisms that have already died. Paleontology is the study of fossils or extinct organisms. Fossils are the most important source for
information of evolution we have. Fossils are dated using radioactive dating.
Radiometric dating provides an estimate of the age of a fossil:
16
Some of Darwin’s evidence came from comparing body parts of different species.
Homologous structures are features that are features that are similar in structure but appear in different organisms and have different
functions. Organisms that share a homologous set of body parts are believed to have descended from a common organism. However, a similar
structure doesn’t mean species are closely related. Analogous structures perform a similar function, but are not similar in origin. A common
environmental challenge caused both functions to develop into a similar structure through natural selection, but the two organisms with the
structure are not thought to have been developed from a common ancestor.
Comparing the embryos of different organisms can also support the theory of evolution. Different organisms can have embryos that have
similar features. This may support the idea that a certain group of organisms descended from a common ancestor.
Biogeography is the study of the distribution of organisms around the world. An important example in how geography affects evolution is with
the Galapagos Finches. Different conditions favored different adaptations and caused the finches to evolve into separate species with
adaptations specialized to its own environment.
Molecular biology supports the theory of evolution because scientists can now study genetic similarities and differences among organisms as
well as comparing proteins. Some ways are:
DNA Sequencing to compare genes of different organisms
Studying which pseudogenes are similar among different organisms.
Studying the relationship of homeobox genes, genes that control the development of specific structures, among different organisms
Comparing the different types of proteins within specific organs between different organisms
Convergent evolution is the evolution towards similar characteristics in unrelated species. Convergent evolution may be caused by similar
environmental conditions favoring certain adaptations. For example, if a certain wing structure is favored by the environment, then multiple
species may evolve towards having that wing structure.
Divergent evolution is the evolution of a species into different species. This may occur through differing environmental conditions.
Coevolution is the process in which two or more species evolve in responses to changes in each other. For example, certain bears feed on
certain fish in a river. The bears adapt to become faster so they can catch the fish. The fish then adapt to become more camouflaged in the
water. The bears then develop sharper eyes to see the fish more easily. The process continues. Coevolution can lead to an “evolutionary arms
race” in which predators evolve into having more adaptations that help catch prey and the prey develop more defenses to protect them from
the predators.
Punctuated equilibrium is a theory that states that evolutionary changes such as speciation occur in bursts followed by a period of evolutionary
inactivity.
Adaptive radiation is the evolution of one species into many different species within a short period of time. An example is the evolution of
mammals after the cretaceous period. A single mammal may have evolved into many types of organisms.
SC.912.L.15.2
Objective: Discuss the use of molecular clocks to estimate how long ago various groups of organisms diverged evolutionary from one another.
Molecular clocks are models that use mutation rates to measure evolutionary time. Scientists determine the mutation rate by comparing the
mutation rates when the time of divergence is known. They can also compare molecular data with the first appearance of each type of
organism in the fossil record.
Scientists can use mitochondrial DNA and ribosomal RNA as two types of molecular clocks.
Mutations occur at a constant rate over time.
SC.912.L.15.3
Objective: Describe how biological diversity is increased by the origin of new species and how it is decreased by the natural process of
extinction.
The origin of new species may introduce new types of proteins and different biological features. If a new type of organism appears with a new
feature that has never been seen before, then that adds to the diversity of organisms.
17
Extinction may remove certain proteins and biological features from a population.
SC.912.L.15.4
Objective: Describe how and why organisms are hierarchically classified and based on evolutionary relationships.
Taxonomy is the science of naming and classifying organisms. The purpose of classification gives scientists a way to refer to species and
organize the diversity of living things. A single species may have different common, everyday-use names in different places, but the Linnaean
system of binomial nomenclature (use of two names) allows scientists to accurately communicate species. The scientific name of an organism
consists of the genus and the species.
Linnaean classification has 7 levels of taxons.
Kingdom
Phylum
Class
Order
Family
Genus
Species
General groups of organisms are listed towards the top, while more specific organisms are listed towards the bottom. Also, different organisms
have a more recent common ancestor if they both are in a more specific taxon. For example, two species in the same genus are more related
than two organisms in the same phylum, considering that the two organisms in that phylum are not in the same genus. The Linnaean system is
a nested hierarchy, in which more specific groups are nested within larger groups.
Organisms are also studied by their evolutionary history, also known as phylogeny.
Molecular clocks are models that use mutation rates to measure evolutionary time.
The more time that passes since diverging from a common ancestor, the more mutations will have occurred and therefore there will be more
differences at the molecular level.
Cladistics is the classification of animals based on a common ancestry. In a cladogram, the evolutionary relationship between organisms is
studied because it explains which organism are the most related to each other by common ancestry and how the organism evolved. Closely
related species share a large number of derived characters, traits labeled on a cladogram.
The goal of Cladistics is to place species in the order in which they descended from a common ancestor.
A clade is a group of species that shares a common ancestor. Derived characters are traits labeled on a diagram. A node is a place where a
branch splits.
18
SC.912.L.15.5
Objective: Explain the reasons for changes in how organisms are classified.
The classification of organisms has changed because new information was introduced that led to new scientific beliefs.
Here is the history of classification of the kingdom system:
Linnaeus classified all organisms as either plants or animals.
Single-celled organisms were moved to the kingdom Protista.
Prokaryotes were moved from the Protista kingdom to the Monera Kingdom because they contain no nucleus.
Fungi are classified as their own kingdom because of the distinctive way in which they feed from plants.
Ribosomal RNA research suggests that the Monera kingdom should be divided into Bacteria and Archaea.
It is evident that the classification system has evolved because of new research and data.
SC.912.L.15.6
Objective: Discuss distinguishing characteristics of the domains and kingdoms of living organisms.
Bacteria are unicellular prokaryotes and one of the largest groups of organisms on Earth. They can be characterized by their shape, need for
oxygen, and whether they cause disease or not. Cell walls contain peptidoglydan.
Archaea are unicellular prokaryotes, just like bacteria, but are characterized by a different chemical structure of the cell walls. They can live in
extreme environments. Cell walls do not contain peptidoglydan.
Eukarya composes all organisms whose cells have a nucleus and membrane-bound organelles. Eukarya is divided into Protista, Fungi, Animalia,
and Plantae.
Kingdom Animalia consists of multicellular heterotrophs. They contain no cell walls and are capable of movement. 99% of all animals are
invertebrates, found mostly in the ocean and consisting of insects, arthropods, etc. There are 35 phyla of animals.
Kingdom Plantae consists of multicellular photosynthetic autotrophs. Cells contain chloroplasts and cellulose in their cell walls.
Kingdom Fungi consists of mostly multicellular eukaryotes. They are heterotrophs and can be distinguished from plants because of the
distinctive way they get food, by absorbing nutrients rather than through photosynthesis. Cell walls contain chitin.
Kingdom Protista are leftovers of uncategorized organisms. They are mostly microscopic organisms that do not fit into one of the other
categories. The fact that they are so diverse makes them extremely difficult to classify.
SC.912.L.15.7
Objective: Discuss distinguishing characteristics of vertebrate and representative invertebrate phyla and chordate classes using typical
examples.
Vertebrates are animals that possess an internal skeleton that has a backbone made up of a vertebrae column. Subphylum Vertebrata is a
group within phylum chordate.
Characteristics of vertebrates include:
Bilateral symmetry (symmetric on both sides)
Body segmentation (head, torso, abdomen, legs)
Endoskeleton
Closed blood system
Tail at some stage of development (embryonic stage in humans and many others)
19
Invertebrates are a broad collection of animals, all of which lack a backbone.
Invertebrates may include sponges, jellyfish, hydra, sea anemones, corals, flatworms, mollusks, arthropods, segmented worms, etc.
SC.912.L.15.8
Objective: Describe the scientific explanations of the origin of life on Earth.
This stuff comes up every year on the EOC.
There are different theories to propose how life on Earth began.
Two hypotheses about how organic molecules arrived on Earth. Either one or both could have occurred.
Miller & Urey’s experiment showed that the Early atmosphere’s chemical structure along with lightning, amino acids could be
formed.
Amino acids could have been brought to Earth by asteroids and meteorites.
There are two main hypotheses about how early cell structures have formed.
In the iron-sulfide bubble hypothesis, scientists noticed that hot iron sulfide combines with cool ocean water to form chimney
structures with many compartments. Biological molecules combined in these compartments about 4 bya. The walls of these
compartments acted as the first cell membranes. Organisms could leave the compartments after they evolved to have cell
membranes.
In the lipid membrane hypothesis, lipid molecules naturally form spheres called liposomes, which may have formed around organic
molecules and act as the cell membrane. Liposomes may have been the first cells.
The RNA hypothesis states that RNA, not DNA, was the genetic material that stored information in the early Earth. Scientists have discovered
that RNA can catalyze chemical reactions. A ribozyme is an RNA molecule that can catalyze specific chemical reactions. Ribozymes can catalyze
their own replication and synthesis. RNA can also copy itself, chop itself into pieces, and make more RNA from those pieces. There is also other
evidence in support of the RNA hypothesis. For example, short chains of RNA will form from inorganic materials in a test tube. RNA can also
form into various shapes depending on the nucleotide sequence. However, RNA does not catalyze reactions as well as proteins nor does it store
genetic information as well as DNA.
Eukaryotes may have evolved through the endosymbiosis theory. Primitive mitochondria and chloroplast may have entered primitive cells. The
larger cell would get more energy in the form of ATP and/or was able to produce sugars. In exchange, the mitochondria and chloroplasts got a
stable environment as well as nutrients. This would explain why mitochondria and chloroplasts have their own DNA and ribosomes. The DNA is
genetically similar to that of a prokaryote.
SC.912.L.15.9
Objective: Explain the role of reproductive isolation in the process of speciation.
Reproductive isolation occurs when members of different populations can no longer mate successfully with one another. Reproductive isolation
is the final step in which a species evolves into two different species. The rise of two or more species from one species is called speciation.
20
This is important because once two populations that used to be one species have reached this stage of speciation, they are said to be two
different species.
SC.912.L.15.10
Objective: Identify basic trends in hominid evolution from early ancestors 6 million years ago to modern humans, including brain size, jaw size,
language, and manufacture of tools.
Over the last 6 million years, hominid brain size has increased. Modern humans have a brain volume of about 1300 cm2, while hominids as early
as 4 million years ago had a brain volume of 430 cm2. The increase of brain size posed an especially strong selective advantage among hominids
against other groups of organisms.
Tools were first used by hominids about 2.5 million years ago. Since then, tools have shown a steady trend of increasing sophistication and
usefulness.
It is believed that vocal languages started diversifying in hominids at about 100,000 years ago.
A human is a primate. A primate is a mammal characterized by flexible hands and feet, forward-looking eyes, and enlarged brains relative to
body size as well as arms that can rotate in a circle and in many cases an opposable thumb.
Before the ability to make tools and enlarged brains, hominids became bipedal, animals that walk on two legs. Hominids changed from having
to travel on four limbs to traveling on two limbs because of anatomical changes, especially to the skeletal system. Hominid evolution also shows
an increase in brain size over time. Modern humans evolved about 100,000 years ago. The increase in brain size and the use of tools and culture
were instrumental in their survival.
SC.912.L.15.11
Objective: Discuss specific fossil hominids and what they show about human evolution.
There are two main groups of hominids. The Australopithecus afarensis lived 3 to 4 million years ago in Africa. It had a smaller brain than
humans, but did have humanlike limbs. The genus Homo lived since 2.5 million years ago. They used tools and may have lived alongside the
genus Australopithecus.
Homo habilis, also known as the handy man, is the earliest member of the genus Homo. It is the earliest known hominid to make stone tools.
The brain was larger than that of the Australopithecus.
Homo Neanderthalensis, found in Germany’s Neander Valley, lived 200,000 years ago to 30,000 years ago. They used tools and lived in social
groups. They may have become extinct because of competition between Homo sapiens.
SC.912.L.15.12
Objective: List the conditions for Hardy-Weinberg equilibrium and why these conditions are not likely to appear in nature. Use the HardyWeinberg equation to predict genotypes in a population from observed phenotypes.
Hardy-Weinberg equilibrium is the condition in which a population’s allele frequencies for a given trait do not change from generation to
generation.
In order for a population to be in Hardy-Weinberg equilibrium, the population must meet 5 criteria:
A very large population in order to remove genetic drift
No immigration nor emigration to remove gene flow
No mutations so that new alleles can be added to the gene pool
Random mating and the removal of sexual selection
No natural selection so that all traits are equally advantageous in survival
5 factors that lead to evolution are the opposites of the previous list.
It is apparent that populations in equilibrium are almost impossible to achieve.
Not all populations are necessarily large.
There is usually immigration or emigration to or from a species unless it is isolated from other members of the same species.
Mutations are random events that cannot be predicted nor prevented.
Sexual selection cannot be removed because females are especially picky about mates who have certain features.
It is most likely that different traits have different advantages in an environment.
The Hardy-Weinberg Equation is as follows:
𝑝 + 2𝑝𝑞+𝑞 = 1
This can be used for traits that have simple dominant-recessive systems.
It is also worth knowing that this equation has the same relationship as the equation 𝑝 + 𝑞 = 1 (square both sides of this equation
to get the top one)
If given a set of genotypes or phenotypes and genetic data does not match the equation, the population is evolving. For example, if the amount
of homozygous dominant is 15%, heterozygous is 55%, and homozygous recessive is 30%, then 𝑝 + 𝑞 ≠ 1 because √. 15 + √. 30 ≈ .39 + .55 =
.94 and. 94 ≠ 1. Thus, the population is evolving.
21
Consider the following punnet square, where p represents a dominant trait while q represents a recessive trait:
p
q
P
pp
pq
q
pq
qq
It may be helpful to draw a punnet square when solving these problems.
SC.912.L.15.13
Objective: Describe the conditions required for natural selection, including: overproduction of offspring, inherited variation, and the struggle to
survive in differential reproductive success.
An adaptation is an inherited trait that gives an advantage to individual organisms and is passed on to future generations.
Overproduction of offspring guarantees that some will survive and reproduce while some may not survive to reproduce. It also increases
competition among the offspring for resources.
The variation of organisms is the basis of natural selection. These differences result in differences in the genetic material of the organisms.
Certain variations allow certain members of a species with a certain trait to survive better than other members of the same species. Those are
naturally selected to live longer and produce more offspring.
Over time, a large percentage of a population will contain the beneficial trait.
A normal distribution is a type of allele frequency distribution in which the frequency is highest towards the mean value and decrease at the
end of each extreme.
Microevolution is the observable change in the allele frequencies of a population over time.
Directional selection occurs when an extreme phenotype is advantageous and a shift in a population’s phenotypic distributions
occurs.
Stabilizing selection occurs when the intermediate phenotype is advantageous.
Disruptive selection occurs when both extreme phenotypes are favored. This may lead to speciation.
22
SC.912.L.15.14
Objective: Discuss mechanisms of evolutionary change other than natural selection such as genetic drift and gene flow.
Genetic drift is the change in allele frequencies due to chance. Genetic drift usually occurs in smaller populations. There are two common
processes that cause a population to become small enough so that genetic drift can occur. The resulting population has different allele
frequencies: the Bottleneck Effect and the Founder Effect.
The bottleneck effect occurs when something happens to a population, and the majority of its members are killed. Certain alleles may have
been lost while some may become permanently in a population. The gene pool of the resulting population may not resemble that of the
original population. This change in allele frequencies is the result of a random event, so this is a type of genetic drift.
The founder effect occurs when a small number of individuals become separated from the original population. For example, if a small group of
birds are separated from the original population and are now geographically isolated, The new group has a different set of allele frequencies
than the original population. The new population may have lost certain traits and some traits may become more dominant. This new group may
evolve differently into different species than the original group.
Another method other than natural selection by which evolution can occur is by sexual selection. While males produce many sperm, females
only produce a few eggs, making females picky about their mates. Sexual selection occurs when certain traits increase the success of mating.
Two types are intersexual (when males impress and attract females) and intrasexual (when males compete for females).
Speciation occurs when two or more species rise from one existing species.
Reproductive isolation: Final step in becoming separate species
Behavioral isolation: isolation resulting in differences in courtship or mating behaviors
Geographic isolation: isolation resulting from separation by physical barriers
Temporal isolation: exists when a timing patterns prevents reproduction between populations
Convergent evolution is the evolution towards similar characteristics in unrelated species. Convergent evolution may be caused by similar
environmental conditions favoring certain adaptations. For example, if a certain wing structure is favored by the environment, then multiple
species may evolve towards having that wing structure.
Divergent evolution is the evolution of a species into different species. This may occur through differing environmental conditions.
Coevolution is the process in which two or more species evolve in responses to changes in each other. For example, certain bears feed on
certain fish in a river. The bears adapt to become faster so they can catch the fish. The fish then adapt to become more camouflaged in the
water. The bears then develop sharper eyes to see the fish more easily. The process continues. Coevolution can lead to an “evolutionary arms race” in which predators evolve into having more adaptations that help catch prey and the prey develop more defenses to protect them from
23
the predators.
Punctuated equilibrium is a theory that states that evolutionary changes such as speciation occur in bursts followed by a period of evolutionary
inactivity.
Adaptive radiation is the evolution of one species into many different species within a short period of time. An example is the evolution of
mammals after the cretaceous period. A single mammal may have evolved into many types of organisms.
SC.912.L.15.15
Objective: Describe how mutation and genetic recombination increase genetic variation.
Mutations may increase genetic diversity by adding new alleles to the gene pool. If this is an advantageous allele, then natural selection may
cause this new allele to become more common. Mutations are the fastest ways by which evolution occurs.
Genetic recombination can increase genetic diversity by combining different alleles in different ways. Recombination occurs mostly during
meiosis, when gametes are made. Each parent’s alleles are combined in different ways. If a certain combination of alleles is advantageous, then
that combination of alleles may become more common by means of natural selection.
Crossing over, another process that increases genetic diversity, is the exchange of chromosome segments between homologous chromosomes
during prophase 1 or meiosis 1. Genetic linkage is the idea that genes located closer together on a chromosome are likely to be inherited
together. A linkage map shows the relative location of genes and can help determine whether or not they are likely to be inherited together.
Florida Standard 16: Heredity and Reproduction
DNA stores and transmits genetic information. Genes are sets of instructions encoded in the structure of DNA.
Genetic information is passed from generation to generation by DNA in all organisms and accounts for similarities in related
individuals.
Manipulation of DNA in organisms has led to commercial production of biological molecules on a large scale and genetically
modified organisms.
Reproduction is characteristic of living things and is essential for the survival of species.
SC.912.L.16.1
Objective: Use Mendel’s laws of segregation and independent assortment to analyze patterns of inheritance.
You do need to know how to do a monohybrid punnet square (2 x 2) and a dihybrid square (4 x 4).
A trait is a characteristic that is inherited. Genetics is the study of biological inheritance patterns and variation in organisms.
Gregor Mendel, a monk, also known as the father of genetics, was the first to discover hereditary units. He laid the ground works for all modern
genetics.
A purebred organism is one that has two of the same alleles for a given trait. A cross is a mating of two organisms in genetics.
24
When Mendel performed his experiments, he observed similar patterns for different traits. For all of his F2 plants, the ratio of dominant to
recessive phenotypes was about 3 to 1.
The law of segregation is Mendel’s first law, stating that:
Organisms inherit one copy of each gene from each parent.
Organisms only donate one copy of each gene in their gametes. Thus, the two alleles separate during gamete formation.
The law of independent assortment is Mendel’s second law, which states that allele pairs separate independently of each other during gamete
formation. Thus, different traits appear to be inherited separately. This was discovered while performing dihybrid crosses.
If the parental genotypes are GGWW and ggww, then the parental gametes must be GW and gw. Thus a cross between the parental plants led
to an F1 genotype of GgWw. Therefore, the F1 gametes are GW, Gw, gW, and gw. The F1 gametes inherit one allele from each trait. For the first
trait, it can inherit a G or a g allele. For the second, it can inherit a W or a w allele. If the F1 gametes are GW, Gw, gW, and gw, then the possible
F2 genotypes and phenotypes are listed below in the punnet square.
The law of independent assortment states that, in the context of this example, the alleles of one trait are separated separately from other
traits. The first trait (G/g) separates during meiosis separately from the second trait (W/w). The inheritance of one trait does not influence the
inheritance of the other in any way, shape, or form. A scientist cannot study one trait to determine the genotype of another trait.
Furthermore, different crosses have different phenotypical and genotypical ratios of offspring.
25
A homozygous-homozygous monohybrid cross has a genotypical ratio of 1:1:1:1 and a phenotypical ratio of 1:1. 100% of offspring
are heterozygous dominant.
A heterozygous-heterozygous monohybrid cross has a genotypical ratio of 1:2:1 and a phenotypical ratio of 3:1.
A heterozygous-homozygous monohybrid cross has a genotypical ratio of 1:1 and a phenotypical ratio of 1:1.
A testcross is a cross between an organism with an unknown genotype and an organism with the recessive phenotype. It is used to determine
whether an organism is homozygous dominant or heterozygous. It is not used to determine whether it is homozygous recessive for that trait
because if it was, then that recessive trait would be expressed because it has 2 recessive alleles. The organism with an unknown phenotype is
crossed with a homozygous recessive organism.
If any of the offspring are homozygous recessive, then the plant with the unknown genotype is a heterozygous organism. The
offspring would receive one recessive allele from the homozygous plant and another from the plant with the unknown genotype.
If the plant with the unknown genotype is homozygous dominant, then it must pass on the dominant trait to the offspring, causing
the offspring to display the dominant trait.
A dihybrid cross has a phenotypic ratio of 1:3:3:9 and a genotypic ratio is 1:2:2:1:4:1:2:2:1.
SC.912.L.16.2
Objective: Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sexlinked, polygenic, and multiple alleles.
A dominant allele is the allele that is expressed when two different alleles or two dominant alleles are present. For example, the alleles for blue
and brown eyes are B and b, respectively. If a person has a genotype of Bb or BB, then the person will have brown eyes, because the B allele is
dominant over the b allele.
A recessive allele is the allele that is only expressed when two copies are present. Going back to the previous example, the only way that a
person can have blue eyes is if that person has a genotype of bb. Any other combination of alleles would have a B in it and the B would be
expressed.
It is important to know that a capital letter refers to a dominant allele and a lowercase letter refers to a recessive allele.
It is also important to know that a dominant allele is not necessarily stronger, better, or more advantageous than another allele.
Codominance occurs when both alleles of a gene are expressed completely. This occurs when there are two dominant alleles present. An
example is blood type. IA and IB are dominant, and i is recessive. Blood type is also a multiple-allele trait because there are multiple possible
alleles that can be inherited.
Incomplete dominance occurs when the phenotype expressed is somewhere between the two homozygous phenotypes. Neither allele is
completely dominant nor recessive.
26
Polygenic traits are traits produced by two or more genes. For example, four genes are used to control skin color.
Sex-linked traits are traits that are passed down on the sex chromosome (chromosome 23). To understand sex-linked traits, you need to know
how to use and read a pedigree, a chart that can help trace phenotypes and genotypes in a family to determine whether people carry recessive
alleles. Use the following chart. Notice that all of the males have the trait or disease or they don’t have it at all. Females can not have it at all, be
a carrier, or have the trait or disease.
This stems from the fact that the Y-chromosome does not carry alleles other than to develop an embryo into a male. Notice that the Y’s don’t have any superscripts on top of them.
In order for a male to express the trait (XmY), the mother must either be a carrier (XMXm) and pass on the recessive allele or must also
express the trait (XmXm).
In order for a male to not have it at all (XMY), the mother must either be heterozygous dominant (XMXm) and pass on the dominant
trait (which is not having it) or not have it at all (XMXM).
Notice that whether the males have it or not is determined by the mother, not the father.
A male cannot be a carrier. They can only have the allele or not have it at all.
In order for a female to have the disease (XmXm), the father must also have it (XmY) and the mother must also have it (XmXm) or be a
carrier (XMXm) and pass on the recessive trait.
In order for a female to be a carrier of the disease (XMXm), she must receive one dominant and one recessive allele. It does not
matter from which parent each comes from.
In order for a female to not have it at all (XMXM), the father must not have it at all (XMY) and the mother either doesn’t have it (XMXM)
or is a carrier (XMXm) but passed on the dominant allele.
You may be asked to figure out the genotype of an individual member of a family. It may be helpful to draw a punnet square. Remember that
on the exam you will have scrap paper to do that. Also remember that they may not always give you a key so you need to know that a circle is a
female and that a square is a male. Also, sometimes you cannot figure out the exact genotype of a person for a sex-linked trait with the given
information. In the figure above, persons 5, 8, and 11 are unknowable until there is some data about their offspring.
You can create a punnet square to help figure out what the genotypes of a person for a sex-linked disease is. The following is a modified punnet
square to show the possibilities of what children a couple can produce with certain genotypes. Everything in green refers to the parents and
everything in yellow refers to the possible offspring. Since you have until the end of the day to finish the test it is worth taking 5 minutes to
make one of these.
Mother
XMXM
XM Xm
XmXm
27
XM Y
X X
XM Y
XMXM
XM Xm
XM Y
XmY
XmY
XM Xm
XM Y
XM Xm
XmXm
XM Y
XmY
Father
M M
XM Xm
XmY
XmXm
XmY
Autosomal (non sex-linked) traits are simple recessive-dominant systems. You may also have to solve the genotypes of some individuals.
In females of mammals, X-chromosome inactivation occurs because one of the two X-chromosomes in females is randomly deactivated.
Therefore, female cells have a variety of different cells. Some cells have an active X chromosome from the mother, while some have an active X
chromosome from the father.
The probability that an offspring gets a certain trait is calculable. Probability is the likelihood that an event happens. Probability is the number
of ways a specific event can occur divided by the number of total possible outcomes.
Going back to this example, the probability that the offspring is a white flower is 25%, because out of all four possibilities, there is one way in
which the flower is white. The probability that the offspring is purple is 75%. Out of the four possibilities, there are 3 ways in which it can be
purple. You can also calculate the probability of the offspring being heterozygous or homozygous. 2 of 4 are homozygous, and the other 2 are
heterozygous. Therefore there is a 50-50 chance as to whether the offspring will be heterozygous or homozygous.
SC.912.L.16.3
Objective: Describe the basic process of DNA replication and how it relates to the transmission and conversation of genetic information.
28
DNA is composed of:
Nucleotides that contain a phosphate group, deoxyribose, and a nitrogen containing base (A,C,T,G).
The phosphate group and the deoxyribose compose the backbone of the DNA strands.
Hydrogen bonds that connect A to T and C to G (base pairing rules)
Two strands of DNA arranged in a double helix.
Watson and Crick developed the first accurate model of DNA.
DNA is universal, meaning that all organisms use DNA as a means of storing genetic information. All cells have all of the components of DNA.
DNA replication is the process by which DNA is copied during the cell cycle.
Replication occurs during the S phase of the cell cycle.
The use of proteins is essential during the replication process. DNA helicase is an enzyme that unzips a double helix strand of DNA. DNA
polymerase is an enzyme that forms bonds between nucleotides during replication.
The DNA replication process:
DNA helicase unzips the double helix at numerous places.
DNA polymerase bond free-floating nucleotides to nucleotides attached to a strand together.
Two identical DNA molecules result.
DNA replication:
Can occur at many places at once.
Can work at up to 50 nucleotides per second.
Works with about 1 per 1 billion errors.
The central dogma is the theory that information flows in one direction, from DNA to RNA to proteins.
RNA, ribonucleic acid, is a chain or nucleotides and a nitrogen-containing base that allows for the transmission of genetic information and
protein synthesis. It is a temporary copy of DNA that is used and destroyed.
RNA differs from DNA:
Sugar in RNA is ribose, not deoxyribose.
RNA has uracil place of thymine.
RNA is a single strand of nucleotides, not two strands.
Transcription is the process of copying a sequence of DNA to produce a complementary strand of RNA. RNA polymerases, enzymes that bond
nucleotides together to form a new chain of an RNA molecule, are large enzymes that have a variety of roles in the transcription process.
Steps to transcription:
RNA polymerase recognizes the transcription start of a gene. A segment of DNA unwinds.
RNA polymerase creates a complementary strand of mRNA. Uracil is used in place of thymine.
The RNA strand detaches completely from DNA.
Types of RNA:
Messenger RNA is an intermediate message that is translated to form a protein.
Ribosomal RNA is a part of the ribosome.
Transfer RNA brings amino acids from the cytoplasm to a ribosome to produce a protein.
Replication and Transcription:
29
Translation is the process that translates mRNA into a polypeptide (protein). MRNA is read in a triplet code using a codon, a sequence of three
nucleotides that codes for an amino acid. Because there are 4 possible nucleotides and 3 spots, there are 64 possible combinations.
You need to know how to read the chart from above, but you do NOT need to memorize it. Each sequence has a start codon, a codon that
signals the start of the translation, and a stop codon, a codon that signals the end of translation.
Translation occurs in ribosomes. Ribosomes have 3 binding sites. A tRNA molecule binds to each of them to form a polypeptide. TRNA
molecules have an anticodon, a set of three nucleotides that is complementary to an mRNA codon.
The steps for translation are:
A start codon signals a tRNA with a complementary anticodon.
The ribosome pulls the mRNA strand the length of one codon.
A codon on the mRNA sequence attracts a tRNA molecule with a complementary anticodon and containing a certain amino acid.
A peptide bond forms between the amino acids.
The process continues until the stop codon on the mRNA strand is reached.
30
A mutation is an unintentional change in an organism’s DNA.
Types of mutations are gene mutations and chromosomal mutations.
Two types of gene mutations are point mutations and frameshift mutations. In a point mutation, one nucleotide is substituted by another. It is
usually caught and fixed by DNA polymerase. A frameshift mutation involves the insertion or deletion of a nucleotide. It has a much greater
effect on the reading of codons and protein formation because most or all of the codons that follow the mutation will be read as incorrect. (See
the diagram below.)
Types of chromosomal mutations involve changes in the number or structure of chromosomes, including:
Deletion
Duplication
Inversion
Translocation
31
Mutations may or may not affect the phenotype, depending on circumstances. Chromosomal mutations tend to have the largest impact on an
organism because they involve an entire chromosome, not just a single gene. Gene mutations can also have a large effect on an organism. A
gene mutation can render a protein’s function useless because it may no longer be able to fit into an enzyme (biological catalyst). A mutation
will not affect a phenotype if the incorrect codon codes for the same amino acid as the correct codon. If AAG changes to AAA, there is no effect
because the resulting protein still has lysine, the correct protein. Such a mutation is called a silent mutation. An incorrect amino acid that has a
similar size or shape as the correct amino acid, or one that is far from an active site on an enzyme, may not have a large effect either. Also, if a
mutation occurs in an intron, a noncoding region, then the mutation will not affect the phenotype.
A mutation only affects offspring if the mutation occurs in a gamete, not a body cell. This makes sense because only the genes from the sex cells
are passed onto the offspring. If a few body cells develop a mutation, those errors are not passed down to offspring because they are not in a
female egg or a male sperm.
In prokaryotes, promoter is segment of DNA that allows a gene to be transcribed. An operon is a segment of DNA that includes a promoter, an
operator (a segment of DNA that activates or deactivates a gene), and one or more genes. View the following two visuals to help understand
how a lac operon in prokaryotes works.
In eukaryotes, an intron is a region of DNA that does not code for a protein. An extron is a region of DNA that does code for a protein.
A mutagen is a substance that can cause a mutation to occur.
SC.912.L.16.4
Objective: Explain how mutations in the DNA sequence may or may not result in a phenotypic change. Explain how mutations in gametes may
result in phenotypic changes in offspring
Chromosomal mutations will affect many genes and usually have a large effect on organisms. Gene mutations can also affect the organism.
Gene mutations may or may not affect phenotype.
A mutation may affect phenotype if the incorrect (mutated) codon codes for a different amino acid than the unaffected codon. If an AAG codon
changes to CAG, the mutation results in a different amino acid being produced and thus the protein may not be able to function correctly.
A mutation will not affect phenotype if the mutation results in a codon that produces the same amino acid as the original codon. For example, if
UUA mutates to UUG, phenotype will not be affected because both code for leucine. This type of mutation is called a silent mutation. It is a
mutation, but it does not impact the organism’s phenotype.
Mutations may result in phenotypic changes in offspring only if the mutation occurs in a gamete, or a germ cell. This is because body cells are
not used to carry genetic information into offspring. The mutation that occurs in the gamete fuses with its counterpart to produce offspring.
Now the mutation that occurred in the gamete will be present in the offspring.
Mutations in germ cells usually have a harmful effect on the organism, but can also, but rarely, produce a beneficial trait in the organism’s survival.
SC.912.L.16.5
Objective: Explain the basic processes of transcription and translation, and how they result in the expression of genes.
Transcription is the process by which a strand of mRNA is created from a sequence of DNA. Translation is the process by which a protein is
created from a strand of mRNA. The standard SC.912.L.16.3 explains these processes as well as includes diagrams of both processes.
Steps to transcription:
RNA polymerase recognizes the transcription start of a gene. A segment of DNA unwinds.
RNA polymerase creates a complementary strand of mRNA. Uracil is used in place of thymine.
The RNA strand detaches completely from DNA.
The steps for translation are:
A start codon signals a tRNA with a complementary anticodon.
The ribosome pulls the mRNA strand the length of one codon.
A codon on the mRNA sequence attracts a tRNA molecule with a complementary anticodon and containing a certain amino acid.
A peptide bond forms between the amino acids.
The process continues until the stop codon on the mRNA strand is reached.
Both processes result in the expression of genes. By transcription, a strand of complementary mRNA is produced to a strand of DNA. The mRNA
strand moves out of the nucleus and travels to a ribosome. By translation, mRNA, rRNA, and tRNA work together to produce a polypeptide, or
32
protein. The protein then moves to perform its function in the body. The theory that genetic information moves in one direction from DNA to a
protein is called the central dogma.
SC.912.L.16.6
Objective: Discuss the mechanisms for regulation of gene expression in prokaryotes and eukaryotes at the transcription and the translation
level.
Organisms regulate gene expression by turning them on and off in order to better respond to stimuli and maintain homeostasis.
Gene regulation in prokaryotes starts at the beginning of transcription. In prokaryotes, DNA may contain an operon structure, a region of DNA
that includes a promoter, and operator, and a gene. A promoter is a DNA segment that allows a gene to be transcribed. An operator is a DNA
segment that turns genes on and off.
One of the earliest examples of an operon is the lac operon, found in bacteria. The operon contains a promoter, an operator, and the gene.
When lactose is absent, a repressor protein binds to the operator, blocking the RNA polymerase from transcription. When lactose is present,
the lactose binds to the protein, changing its shape. The protein detaches from the DNA, and RNA polymerase can transcribe the gene. The
mRNA is translated into a protein, and then the lactose can be broken down.
Maintenance of gene regulation is more complex in eukaryotes, which can occur at many points, not just transcription. Two major places in
which gene expression is regulated is during transcription and mRNA processing. Two factors that affects transcription in eukaryotes are
regulatory gene sequences and transcription factors, a protein.
Regulatory gene sequences are recognized by transcription factors that bind to the DNA strand and help RNA polymerase know where a gene
starts. Promoters can be close or far from the affected genes. However, because DNA is flexible, so the promoter can actually be brought into
close contact with the affected gene sequences. Each gene has a unique combination of regulatory sequences, while some are found in almost
all. For example, the TATA box, a 7 nucleotide promoter (TATAAAA), is found in most eukaryotic cells. DNA sequences such as enhancers and
silencers do affect the rate at which transcription occurs. An enhancer speeds up transcription; a silencer slows it down. Genes can also control
the expression of other genes, and may have a large effect on development of an embryo.
Gene regulation can also occur by removing introns from the DNA sequence and splicing exons together. Introns are rarely found in
prokaryotes.
33
SC.912.L.16.7
Objective: Describe how viruses and bacteria transfer genetic material between cells and the role of this process in biotechnology.
Viruses transfer genetic material between cells by attacking a host cell in order to reproduce. They inject their genetic material into the cell and
take control of the host’s DNA and/or ribosomes.
Bacteria can transfer DNA through conjugation, in which a hollow bridge forms to connect multiple cells. In biotechnology, this can hinder the
use of antibiotics. If antibiotics don’t kill all of the bacteria, the ones that survive may be able to transfer the advantageous genes through this
process. This helps bacteria develop antibiotic resistance.
SC.912.L.16.8
Objective: Explain the relationship between mutation, cell cycle, and uncontrolled cell growth potentially resulting in cancer.
Cancer is the common name for a class of diseases characterized by uncontrolled cell division and the loss in regulation in the cell cycle.
A benign tumor is one that remains clustered together; a malignant tumor is one in which a part of the cancer breaks away (metastasize) and
forms new cancer in other parts of the body. A tumor requires lots of food and blood that contribute nothing to the organism, and can exert
pressure on surrounding organs.
Cancer cells usually carry mutations. They can occur in oncogenes, genes that accelerate the cell cycle, or genes that act slows down the cell
cycle. Other cancers can be caused by factors such as UV radiation, etc. Carcinogens are substances that promote the development of cancer,
such as tobacco.
SC.912.L.16.9
Objective: Explain how and why the genetic code is universal and is common to almost all organisms.
The structure of DNA in all living things is essentially the same. All are composed of deoxyribose, a phosphate group, and 4 nitrogen bases. The
only differences are the amount of bases and the order of the bases. DNA can be removed from one cell and placed in another cell. The second
cell will be able to function just like the first cell because the DNA can still be used by the second cell.
The genetic code may be universal because all organisms may have descended and evolved from a single ancestor. This common ancestor may
have used the same genetic code that all organisms now use. Organisms evolved from this ancestor because of chance mutations and natural
selection. These both have caused
SC.912.L.16.10
Objective: Evaluate the impact of biotechnology on the individual, society, and the environment, including medical and ethical issues.
One of biotechnology’s main concerns deals with DNA and genetics.
A restriction enzyme is an enzyme the cuts DNA at specific nucleotide sequences. Many bacterial cells produce restriction enzymes in order to
defend against viruses. A restriction enzyme will cut a DNA molecule every time it finds an exact DNA sequence. Different restriction enzymes
cut the same DNA segment in different ways. Where it cuts the DNA is a restriction site. They may leave blunt ends where the DNA is cut, or
they may leave sticky ends.
34
Gel electrophoresis is the method of separating various lengths of DNA strands by applying an electrical current to a gel. The DNA sample is
loaded into a gel. Positive and negative electrodes are attached to both ends. Because DNA is negatively charged, it moves towards the positive
electrode. The larger segments move more slowly than the smaller segments. A restriction map is a diagram that shows the lengths of
fragments between restriction sites in the strand of DNA. Information on a restriction map shows only the lengths of the segments and nothing
else about them.
DNA segments can be copied through a polymerase chain reaction, invented by Kary Mullis. All that is needed is a segment of DNA, DNA
polymerases, large amounts of each nucleotide, and two primers. A primer is a short segment of DNA that acts as a starting point for a new
strand. DNA polymerases need this because they cannot start strands, but can add to those that have already been started. There are three
steps.
The container is heated to more than 90 degrees Celsius for a few seconds to separate the strands of DNA.
The container is cooled to about 55 degrees Celsius so that the primers can bind to the DNA strands.
The container is heated to 72 degrees Celsius, the temperature at which the polymerases work best. The polymerases were
obtained from bacteria that live above 80 degrees Celsius in order so that the polymerases can survive the initial heating of the
container.
The process can be repeated in order to produce more segments. After each cycle, the number of segment doubles.
`A DNA fingerprint, a type of restriction map, is a representation of parts of an individual’s DNA that can be used to identify a person at the
molecular level. They can be used to identify relationships within a family. A DNA fingerprint shows differences in the number of repeats of
certain DNA sequences.
Identifying a person with a certain DNA fingerprint depends on the probability that another person has the same repeated area. If a person has
a 1 in 100 chance of having a match at one location, a 1 in 250 chance at another, and a 1 in 500 in another, the probability that a person has all
3 is
×
×
=
. Therefore, a person would have a one in twelve and a half million chance in having a match for all three
,
,
locations.
DNA fingerprints are used for a variety of reasons in society, especially in legal cases. DNA from blood may serve as evidence to prove a person
innocent or guilty of a crime. DNA fingerprinting has been used to identify animals, identify family relationships necessary for immigration, etc.,
and study biodiversity.
A clone of an organism is an exact copy of the organism. While some organisms naturally clone themselves, mammals cannot. To clone a
mammal, a nuclear transfer occurs. During a nuclear transfer, an unfertilized egg is taken from an animal and gets its nucleus removed. The
nucleus of the organism to be cloned is implanted into the egg. The egg is stimulated and then implanted into the female. The first ever clone
was a sheep named Dolly in 1997. However, the personalities and appearances may differ because of environmental factors.
Some benefits of cloning include the use of organs from cloned organisms in order to save lives. Perhaps it could also be used to save
endangered species. However, the success rate for mammals is very low. Even if the cloning is successful, there may be health problems. An
35
environmental concern is that cloned animals in a wild population would reduce biodiversity.
Genetic engineering is the changing in an organism’s DNA to give the organism new traits. This process is possible because DNA is “universal” and is shared by all organisms. Recombinant DNA is DNA that contains genes from multiple organisms. Recombinant DNA can be used so that
organisms of a species can have beneficial traits of another species. For example, it could be used to produce crops that produce medicines and
vitamins. It may also be used to create vaccines against HIV. Bacteria are important in this process, because they contain plasmids, closed loops
of DNA that separate from the bacterial chromosome and replicate on their own within the cell. A transgenic organism has one or more genes
from another organism inserted into its genome.
Genetic engineering in plants is easier to perform than in animals. In plants, a gene is inserted into a plasmid, and the bacteria infect the plant.
This has allowed for the plants to have traits such as resistance to frost, disease, insects, etc. In animals, a fertilized egg must be obtained, the
foreign DNA must be inserted, and then the egg must be implanted back into the female.
Gene knockout is a genetic manipulation in which one or more of an organism’s genes are prevented from being expressed.
Genetic engineering also raises concerns. There may be unknown health effects in Genetically modified crops. GM could reduce biodiversity
and make crops vulnerable to new diseases or pests.
Genomics is the study of genomes, including the sequencing of an organism’s entire DNA. Gene sequencing is determining the order of DNA
nucleotides in genes or in genomes. A radioactive primer is added to a single strand of DNA. Polymerase builds a short segment of a new DNA
strand. The segments are separated by gel electrophoresis. The DNA sequences are determined by the pattern of DNA fragments on the gel.
The human genome project is a project whose goal is to map, sequence, and identify all of the genes in the human genome. The first goal to
sequence all of the base pairs of human chromosomes was accomplished in 2003.
Technology allows the study of both genes and proteins:
Bioinformatics: the use of computer databases to organize and analyze biological data as well as store, share, and find data.
DNA microarrays: tools that allow scientists to study many genes and their expression at once.
Proteomics: study and comparison of all the proteins (and their functions) that result from an organism’s genome.
Genetic screening is the process of testing DNA to determine a person’s risk of having or passing on a genetic disorder.
Gene therapy is the replacement of a defective or missing gene, or the addition of a new gene to treat a disease.
Biotechnology may impact the well-being and health of the individual, society, and the environment. The health of an individual person may be
higher because biotechnology allows for a better understanding on diet, exercise, etc. Biology can help people understand health-related issues
such as disease, cancer, etc.
Biotechnology may allow for an understanding of the environment and ecology. With an understanding of biology, people can make informed
decisions on environmental issues, such as pollution, biodiversity, habitat preservation, land conservation, and natural resource use.
Biotechnology has health benefits. For example, people can be cured of certain diseases because of research done in the topic area. Vaccines
help prevent the spread of disease throughout a population. Another possible benefit is the effect of genetically modified foods. Crops may be
able to have a higher crop yield and a better nutrition value.
The use of biotechnology raises ethical questions. For example, genetic screening is the analysis of a person’s genes to identify genetic
variations. One ethical consideration is the usage of such information. A concern of some people is that insurance companies refuse insurance
to those with a disorder or disease. A larger concern is the chance that people use biotechnology to choose the characteristics of offspring.
In the context of the use of biotechnology, the possible benefits must be weighed against the biological risks and the ethical considerations that
also arise.
One common area of study within the field of biotechnology is the use of stem cells. Stem cells are a unique type of body cell that have the
ability to (1)divide and renew themselves for long periods of time, (2) remain undifferentiated in form, and (3)develop into a variety of
specialized cell types. There are three types of stem cells.
36
Stem cells have been used for treatment for leukemia and lymphoma, and the offer hope for other disabilities. For example, the injection of
healthy cells may increase the overall health of an organ. It may be able to cure paralysis, blindness, etc. However, if they are used in
treatment, they may be rejected as foreign material, or even form a tumor. An ethical consideration is that the use of stem cells requires the
destruction of an embryo.
SC.912.L.16.13
Objective: Describe the basic anatomy and physiology of the human reproductive system. Describe the process of human development from
fertilization to birth and major changes that occur in each trimester of pregnancy.
Male reproductive structures:
Seminal vesicle: secretes a fluid that neutralizes the acidity in the female’s vagina
Prostate gland: produces a fluid that helps sperm move more easily
Vas deferens: long duct through which sperm mixes with other fluids before reaching the urethra
Urethra: tube through which sperm and urine leave the body
Epididymis: coiled tube through which sperm leave the testes
Scrotum: pouch that encloses the testes
Penis: organ in which sperm leave the body
Testes: produces sperm
Female reproductive structures:
Ovaries: contains immature egg cells
Oviduct (fallopian tube): tube from the ovaries to the uterus where the egg is usually fertilized
Uterus: the womb where the fetus develops
Cervix: opening connecting the vagina and the uterus
Vagina: female reproductive opening
Estrogen is a steroid hormone that:
Controls the development of female sexual characteristics
Needed for egg cells to develop fully before leaving the ovaries
Prepares the uterus for pregnancy every month
Testosterone is a steroid hormone that:
Stimulates the production of sperm
Important hormones released from the hypothalamus and pituitary glands are follicle-stimulating hormone and luteinizing hormone during
puberty.
Fertilization occurs when a spermatozoa joins an ovum to produce a zygote with its complete set of genes. This usually occurs in the fallopian
tube, and the fertilized egg embeds itself in the Endometrium, the lining of the uterine wall.
Reproductive functions
The placenta is an organ that carries nutrients from the mother to the embryo.
The umbilical cord, which consists of two arteries and a vein, connects the embryo to the placenta. The embryo will die if the cord is
severed, and allows for the flow of nutrients into the embryo and the removal of wastes from the embryo.
37
The amniotic sac is a fluid-filled organ that cushions and protects the embryo from sudden temperature changes.
Amniotic fluid is taken into and out of the fetus in order to develop the lungs. It cushions the baby from blows to the mother’s abdomen, allows for easier fetal movement, and promotes muscular/skeletal development.
Infertility is the condition in which reproduction is impossible or extremely difficult. A zygote is the fertilized egg.
STDs are diseases that are passed on from person to person through sexual contact.
Embryonic development:
The embryo is more vulnerable to damage by mutations, drugs, etc. during the first trimester.
Stem cell differentiation occurs during the first trimester.
An embryo at 9 weeks is called a fetus
The second trimester has continued development and increased physical movement as well as making the pregnancy noticeable.
Lungs strengthen and are the last organs to develop during the third trimester.
The baby is born at the end of the third trimester.
Important vocabulary for this standard:
Blastocyst: stage of development during which the zygote consist of a ball of cells
Implantation: the embedding of a fertilized egg in the endometrium
Morula: early stage of embryonic development consisting of cells in a solid ball contained within the egg coat
Gastrulation: process by which a hollow sphere of cells in early embryonic development after the morula stage is reorganized into
three layers: the ectoderm, endoderm, and mesoderm
Neurulation: stage of embryonic development in which the primitive central nervous system forms
Stages of birth:
Human development:
Infancy: birth to the time in which they can walk
Childhood: period of life from the ability to walk until puberty
Puberty: sexual maturity and the development of sexual characteristics
Adolescence: In girls, marked by the first menstrual cycle; in boys, marked by sperm in the semen; rewiring of the brain
Adulthood: period of life when a person is fully developed and physical growth stops
Aging: decline in immune functions; lower production of key hormones; rate of metabolism and digestion slow down; thinner skin;
lower bone and muscle mass, etc.
SC.912.L.16.14
Objective: Describe the cell cycle, including the process of mitosis. Explain the role of mitosis in the formation of new cells and its importance in
maintaining chromosome number during asexual reproduction.
The cell cycle is a regular pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells. The cell cycle is divided into Gap 1,
Synthesis, Gap 2, and Mitosis. G1, synthesis, and G2 form the interphase.
In gap 1, a cell carries out its normal functions as well as increase in size of the cell and the number of organelles. Most of the cell cycle is in the
G1 stage. The cell also must have enough nutrition, adequate size, and relatively undamaged DNA to proceed to synthesis safely. Signals from
other cells requiring new cells may also be necessary.
38
In synthesis, the nuclear DNA is copied and replicated.
In gap 2, the cell continues growth and makes sure that everything is prepared for mitosis.
Mitosis is the division of the cell nucleus and its contents. Cytokinesis is the process that divides the cell cytoplasm in order to form 2 cells.
Mitosis is divided into 4 stages.
Prophase: chromatin condenses into tightly coiled chromosomes, each consisting of two identical sister chromatids, nuclear
envelope breaks down, centromeres and centrosomes migrate to opposite sides of the cell; spindle fibers grow
Metaphase: spindle fibers attach to the centromere of each chromosome and then align the chromosome at the equator
Anaphase: sister chromatids separate
Telophase: a complete set of chromosomes is positioned at each end of the cell, and the nuclear membrane reforms.
Cytokinesis is the division of the cytoplasm. In animal cells, the cell wall pinches together. In plants, a cell plate forms.
Mitosis is a form of asexual reproduction, the creation of offspring from a single parent. Mitosis is the process that allows us to grow and
develop. Mitosis maintains chromosome number in offspring because identical chromatids are positioned at each end of the cell before
Cytokinesis. Thus, each daughter cell has one complete set of DNA. When the DNA replicated, two sets of DNA were formed and one was
allocated to each daughter cell.
Mitosis is important for growth and development because it allows for the production of new cells. Organisms grow not by increasing the size
of cells, but rather they increase the number of cells. This is because as a cell size increases, the ratio of surface area to volume decreases. This
is a factor that limits the total size of a cell. Thus, cells must divide and produce new cells via mitosis in order for the organism to grow.
SC.912.L.16.15
Objective: Compare and contrast binary fission and mitotic cell division.
Differences between binary fission and mitosis
Mitosis occurs in eukaryotes; binary fission occurs in prokaryotic bacteria
Bacterial DNA is in the form of one circular chromosome
Bacteria have no spindle fibers
Similarities between binary fission and mitosis
Asexual reproduction of a single cell into two equal parts
Formation of two daughter cells genetically identical to the parent cell
SC.912.L.16.16
Objective: Describe the process of meiosis, including independent assortment and crossing over. Explain how reduction division results in the
formation of haploid gametes or spores.
Meiosis is a form of nuclear division that divides a diploid cell into haploid cells. Meiosis is divided into 2 parts: Meiosis 1 and Meiosis 2.
Chromatids have already been copied prior to meiosis. They are attached at the centromere.
During prophase 1, the nuclear membrane breaks down. Centrioles and centrosomes move to the opposite sides of the cell. Homologous
chromosomes begin to pair up. During this phase, crossing over of DNA segments occurs. Within a tetrad, a pair of two chromosomes,
segments of DNA trade places. At this stage, each chromosome has been duplicated, the sister chromatids are still connected, and homologous
chromosomes are paired with each other. Part of one chromatid may break off and reattach to the other chromatid.
During metaphase 1, the homologous chromosomes align at the equator, randomly. A homologous chromosome on one side of the equator is
paired directly across from its counterpart. In the diagram below, the chromosome on the top left corner has the same genes and is the same
length as the one directly below it. One chromosome was inherited from the father while one was inherited from the mother. The same applies
to the other set of homologous chromosomes. The red chromosome (top right) and the aqua (top left) chromosome have the same genes and
are the same length. However, the red one was inherited by the mother of this organism while the aqua chromosome was inherited from the
father of this organism. The mother’s chromosome will always be directly across that of the father. The purpose of this random lineup is to
increase genetic diversity.
39
During anaphase 1, the paired homologous chromosomes separate and move to the opposite sides. The sister chromatids remain attached for
the rest of meiosis 1.
During Telophase 1, spindle fibers disassemble and the cell undergoes Cytokinesis. The result is two haploid cells. In these two cells, a cell with
the mother’s chromosome means that the other cell has the father’s counterpart.
During prophase 2, centrosomes and centrioles move to the opposite sides of their cells, and spindle fibers assemble.
During metaphase 2, the chromosomes are aligned along the equator of each cell.
During anaphase 2, the sister chromatids are pulled towards opposite ends of the cell.
The nuclear membrane reforms and both cells undergo Cytokinesis. The result is four genetically different daughter cells.
The following information about independent assortment is repeat information from page 18 and 19.
The law of independent assortment is Mendel’s second law, which states that allele pairs separate independently of each other during gamete
formation. Thus, different traits appear to be inherited separately. This was discovered while performing dihybrid crosses.
40
If the parental genotypes are GGWW and ggww, then the parental gametes must be GW and gw. Thus a cross between the parental plants led
to an F1 genotype of GgWw. Therefore, the F1 gametes are GW, Gw, gW, and gw. The F1 gametes inherit one allele from each trait. For the first
trait, it can inherit a G or a g allele. For the second, it can inherit a W or a w allele. If the F1 gametes are GW, Gw, gW, and gw, then the possible
F2 genotypes and phenotypes are listed below in the punnet square.
The law of independent assortment states that, in the context of this example, the alleles of one trait are separated separately from other
traits. The first trait (G/g) separates during meiosis separately from the second trait (W/w). The inheritance of one trait does not influence the
inheritance of the other in any way, shape, or form. A scientist cannot study one trait to determine the genotype of another trait.
Reduction division results in the production of haploid gametes by cutting the number of chromosomes in half. Because a male gamete and a
female gamete are required to produce an embryo, the father and the mother each donate half of their DNA to the offspring. If meiosis did not
reduce the number of chromosomes from 2N to 1N in each gamete, then a combination of two gametes from both the father and the mother
would result in 2N+2N=4N. With each successive generation, the number of chromosomes would double. Because meiosis reduces the number
of chromosomes by ½, then a combination of two gametes from both the father and the mother would result in 1N+1N=2N, a diploid fertilized
cell. Because meiosis reduces the number of chromosomes by half, each successive generation can maintain the chromosome number at 2N, or
a diploid organism.
SC.912.L.16.17
Objective: Compare and contrast mitosis and meiosis and relate to the processes of sexual and asexual reproduction and their consequences
for genetic variation.
Differences between mitosis and meiosis:
Meiosis has 2 cell divisions; mitosis has 1 cell division.
During meiosis, homologous chromosomes pair up along the equator; during mitosis, they never pair up.
In anaphase 1 of meiosis, sister chromatids remain attached; in anaphase of mitosis, sister chromatids separate.
Meiosis creates genetic variety; mitosis creates identical copies of organisms.
Meiosis results in 4 haploid cells; mitosis results in 2 diploid cells.
Mitosis is a form of asexual reproduction. Asexual reproduction is defined as the creation of offspring from a single parent that does not involve
the joining of gametes. However, because this is a form of asexual reproduction, exact copies of the original organism or cell are produced.
Genetically identical offspring may be advantageous in constant conditions because of its efficiency in terms of energy cost, but may be a
disadvantage in a changing environment. Organisms with identical genes interact with and respond to the environment in the same way.
Meiosis is an important factor in sexual reproduction. Because it reduces the number of chromosomes by half, two gametes, each with a half
set, can join to form one complete set of DNA. This maintains the number of chromosomes with each successive generation. Meiosis is used to
produce spermatozoa and ovum, which are the male and female gametes, respectively. Sexual reproduction does have its advantages. An
increased genetic variety increases the chances of survival. However, sexual reproduction requires energy to find a mate.
Florida Standard17: Interdependence
The distribution and abundance of organisms is determined by the interactions between organisms, and between organisms and the
non-living environment.
41
Energy and nutrients move within and between biotic and abiotic components of ecosystems via physical, chemical and biological
processes.
Human activities and natural events can have profound effects on populations, biodiversity and ecosystem processes.
SC.912.L.17.1
Objective: Discuss the characteristics of populations, such as the number of individuals, age structure, density, and pattern of distribution.
A population is a group of the same species that live together in one area.
The number of individuals in a population is counted by counting the number of individual organisms. An organism is a single living thing.
Population density is the measurement of individuals living in a defined space. Population density is calculated by dividing the number of
individual by the area of space.
Population dispersion is the way in which individuals in a population are spread in an area or volume. There are three types of population
dispersion:
Clumped dispersion, where clustering of individuals is advantageous, such as a herd of individuals.
Uniform dispersion, where territoriality is present, such as an equal dispersion of desert plants.
Random dispersion, such as top predators.
The age structure of a population is determined by the survivorship curve. There are three survivorship curves.
If an organism has a type 1 survivorship curve, most individuals live to reproduce and then die as they age. This is common among organisms
such as humans. It is characterized by a low infant mortality rate as well as parental care for the young.
If an organism has a type 2 survivorship curve, an equal number of deaths will occur over time. At all times, organisms, such as birds, have an
equal chance of living and dying.
If an organism has a type 3 survivorship curve, most offspring die at a young age and few live to old age. Fish and invertebrates generally follow
this pattern as an adaptation. The adaptation is to ensure that at least some of the offspring will survive to reproduction. There is a high infant
mortality rate.
SC.912.L.17.2
Objective: Explain the general distribution of life in aquatic systems as a function of chemistry, geography, light, depth, salinity, and
temperature.
The ocean can be divided into zones, each of which is characterized by a variety of different features.
The intertidal zone is a strip of land between high and low tides. Organisms here must tolerate changing levels of water levels, temperature,
amount of moisture, and salinity.
The Neritic zone extends from the intertidal zone out to the edge of the continental shelf. This area contains 40 times more biomass than the
rest of the ocean. Most life that exists here is In the form of plankton, tiny free-floating organisms that live in the water, which can be divided
into zooplankton and phytoplankton. Zooplankton is animal plankton, while phytoplankton is photosynthetic plankton. Phytoplankton is critical
to life on Earth because they provide about 70% of all oxygen and form the base of the oceanic food web. [Pg. 469]
The Bathyal zone extends from the end of the Neritic zone to the base of the continental shelf, between 200 and 2,000 meters. The
accumulation of silt makes the water murky. Fish that have adapted to high water pressure and animals that burrow thrive. The high water
pressure is a result of the depth of the ocean.
42
The abyssal zone lies below 2,000 meters. There are no photosynthetic organisms here because of the lack of sunlight. However,
chemosynthetic organisms are commonly found. Deep-sea vents support a large number of organisms. The depth of the ocean here causes
large water pressure.
Coastal waters contain a large variety of organisms. Coral reefs are ocean habitats found in the shallow coastal waters in a tropical climate.
They may have a large biodiversity because of the wide variety of organisms that live there. Kelp forests, ocean habitats that exist in cold,
nutrient-rich shallow coastal waters, are composed of large communities of kelp.
In a freshwater ecosystem, the variety of organisms depends on factors such as temperature, oxygen levels, pH, and flow rate. Organisms are
adapted to the particular conditions of a specific freshwater ecosystem.
Freshwater ponds and lakes are divided into 3 zones: the littoral zone, the Limnetic zone, and the benthic zone. The littoral zone is analogous to
the oceanic intertidal zone and may contain water lilies, dragonflies, snails, etc. The Limnetic zone, also known as the pelagic zone, refers to
open water farther out from shore, characterized by plankton and fish. The benthic zone is the bottom of the lake, characterized by a shortage
of sunlight and an abundance of decomposers.
During the summer and winter, the lake stratifies, meaning that the different layers have separate temperatures. During the summer, the warm
waters are at the surface and the cool waters are at the bottom. The water “turns over” periodically because it is most dense at 4 degrees Celsius. During the autumn, the surface cools to 4 degrees Celsius, and it sinks to the bottom. During the winter, the surface cools to less than 4
degrees Celsius, causing it to mix with the water underneath. In the spring, the surface turns to 4 degrees Celsius and sinks. In both autumn and
spring, the water at the bottom and the surface water switch places, bringing nutrients to the surface.
SC.912.L.17.4
Objective: Describe changes in ecosystems resulting from seasonal variations, climate change, and succession.
Climate is the long-term pattern of weather conditions in a region, including factors such as average temperature and precipitation and relative
humidity as well as seasonal variations in an area. Temperature and moisture are among the most important in shaping ecosystems. In different
climates, different organisms are able to survive due to adaptations that they have. For example, a polar bear cannot survive in the desert
because it is not adapted to the climate. Organisms can be camouflaged in order to avoid predators. Such organisms may be dependent on
climate in order for the conditions of camouflage to be possible. A microclimate is the climate of a small, specific place within a larger area.
Earth has 3 basic climate zones:
Polar
Temperate
Tropical
Earth has 6 major biomes:
Earth’s biomes have particular characteristics:
43
Seasonal variations also have an effect on ecosystems. Most seasonal variations are derived from the seasons and Earth’s tilted axis as well as
its revolution around the Sun. Throughout the year, equatorial regions receive direct sunlight. Towards to poles, more extreme seasonal
variations occur, such as 23 hours of daylight for 6 months, etc. Equatorial regions are much warmer than the poles as a result of the more
direct sunlight. In addition, because the equator receives the most direct sunlight, more photosynthesis occurs, allowing for vegetative
covering. This includes the tropical rainforest.
Ecological succession is the sequence of biotic changes that regenerates a damaged area or creates a community in a previously uninhabited
area. Two types of succession are primary and secondary succession. Primary succession is the establishment and development of an
ecosystem that was previously uninhabited. The first species to inhabit the area are called pioneer species. Secondary succession is the
reestablishment of a damaged ecosystem in an area where the soil was left intact. Secondary succession is never ending.
44
To differentiate between primary and secondary succession, it is important to distinguish whether the ecosystem is new or has been damaged.
In the figure above (left), the retreating glacier is uncovering new soil, meaning that this is a type of primary succession. In the figure above
(right) the fire still leaves the soil intact as well as feed it nutrients. As a result, this is a type of secondary succession.
In economic succession, older organisms are replaced with newer ones. The mosses and grasses in primary succession are replaced by forests.
The area does not have forests and grasses at the same time. The grasses have been replaced by the forest.
SC.912.L.17.5
Objective: Analyze how population size is determined by births, deaths, immigration, emigration, and limiting factors (biotic and abiotic) that
determine carrying capacity
The biosphere is the part of Earth where life exists. The biota is the collection of living things within the biosphere.
The biosphere constantly interacts with the hydrosphere, the Geosphere, and the atmosphere.
Ecology is the study of interactions among living things.
Levels of ecological organization:
Organism: an individual living thing
Population: a group of the same species that live in an area
Community: group of different species that live together in one area
Ecosystem: includes all organisms and the abiotic factors in an area
Biome: major regional or global community of organisms.
Biotic factors are living or once living things. Abiotic factors are nonliving things in the environment.
Biodiversity is the variety of life in an ecosystem.
A keystone species is a species that has an unusually large effect on its ecosystem.
Carrying capacity is the maximum number of species that the environment can normally and consistently support. The carrying capacity of any
organism is subject to change as the environment changes.
Immigration is the movement of individuals into a population. Emigration is the movement of individuals out of a population and into another
population. Births increase the number of individual in a population by adding individuals to a population. Deaths decreases the population size
when an organism dies.
A limiting factor is any factor that limits the growth and size of a population. There are two types of limiting factors: density dependent and
density independent factors. A density dependent factor is a factor whose strength of influence is affected by the number of individuals living in
an area. For example, the population of a predator can be limited competition for the available prey, and the size of the prey population can be
limited by the predation. Another important density dependent factor is disease, because it will spread faster in denser areas. A density
independent factor is a factor whose strength of influence is not affected by the density of a population. Some examples are unusual weather
and human activities. For example, if a flood occurs in an area, all of the flowers are likely to die. It doesn’t matter how many there are because
they will all be killed by the flood.
There are two types of population growth:
45
A population crash is a dramatic decline in the size of a population over a short period of time.
The carrying capacity of an environment is the maximum number of individuals of a particular species that the environment can normally and
consistently support.
SC.912.L.17.6
Objective: Compare and contrast the relationships among organisms, including predation, parasitism, competition, commensalism, and
mutualism.
Competition occurs when two organisms fight for the same limited resources. Two types are interspecific and intraspecific competition.
Intraspecific competition occurs between members of the same species. Interspecific competition occurs between two different species.
Predation is the process by which one organism captures and feeds on another organism. It is important to note that herbivores can also be
considered predators, because they “capture” the producer and feed off of it.
Symbiosis is a close ecological relationship between two or more organisms that live in direct contact with one another. In mutualism, both
species benefit from the relationship. In commensalism, one organism benefits while the other is unaffected. In parasitism, one organism
benefits while the other is harmed.
Symbiosis
Mutualism
Commensalism
Parasitism
SC.912.L.17.8
Objective: Recognize the consequences of the losses of biodiversity due to catastrophic events, climate changes, human activity, and the
introduction of non-native species.
The preservation of biodiversity is important to the future of the biosphere. In addition, the preservation of biodiversity is important to the
future of humans as well. Much medical and scientific advancement have been derived from biology. If organisms are allowed to become
extinct, these possible medicines may never be found again. In addition, many scientists of almost all fields of science get some inspiration from
biology and nature.
A catastrophic event may cause one or more species to become extinct. For example, a famous theory about the extinction of the dinosaurs 65
million years ago attributes the mass extinction to an asteroid impact. Such a catastrophic event can greatly reduce the biodiversity and the
gene pool of life on Earth.
Climate change is one of the main causes of extinction. For example, when the ice retreated during the last ice age, it is believed that this
caused organisms such as the woolly mammoth and saber-toothed cat to become extinct. Because organisms are adapted to a specific climate
under specific conditions, organisms usually have a hard time adapting to changing climactic conditions. Using a more modern example, if
global warming melts the polar ice caps, organisms such as the polar bear may become extinct. They may be unable to adapt to the increase in
temperature.
Human activity is one of the top causes of extinction. Humans may cause species to go extinct by: destroying habitats, introducing non-native
species to an area, overpopulating, polluting the environment (air and water), and overexploitation of forests. Destroying habitats removes the
environment in which a particular species is adapted to live in. Pollution can alter or damage the habitat in which an organism lives in.
Overpopulation of humans requires an increased demand for food. Overexploitation is the overuse of natural resources, including overfishing,
clear-cutting forests, over farming, etc.
Introducing non-native species (a.k.a. introduced species) is any organism that was brought to an ecosystem as the result of human action.
They can threaten other species if they prey on or crowd out the native species. One well known example of an invasive species is the Burmese
python, introduced into the Florida Everglades. Another example is the kudzu plant, which is invasive in the U.S. Invasive species can be either
plants or animals, and may cause economic damage as well.
46
SC.912.L.17.9
Objective: Use a food web to identify and distinguish producers, consumers, and decomposers. Explain the pathway of energy transfer through
trophic levels and the reduction of available energy at successive trophic levels.
Producers (autotrophs) are organisms that get their energy from nonliving resources. Consumers (heterotrophs) are organisms that obtain
energy by eating other living or once living organisms. Producers usually obtain energy from sunlight in photosynthesis. Other times, chemicals
are used to produce energy in a process called chemosynthesis.
A food chain is a sequence that links species by their feeding relationships. The arrows show the transfer of energy through an ecosystem, not
what eats what. Five types of consumers are:
Herbivores eat plants
Carnivores eat animals
Omnivores eat plants and animals
Detrivores eat dead organic matter
Decomposers break down organic matter into simpler compounds
Consumers can also be described by their “pickiness.” A specialist only eats one specific organism. A generalist feeds on a variety of other
organisms. Specialists are extremely sensitive in the availability of prey. If the prey become extinct, the specialist will have to find another food
source or it will also become extinct.
A trophic level is the level of nourishment in a food chain.
Primary consumers are herbivores that consume the producers
Secondary consumers are carnivores that eat herbivores
Tertiary consumers are carnivores that eat secondary consumers
A food web is a model that shows the complex network of feeding relationships and the flow of energy within and sometimes beyond an
ecosystem. It is important that producers are included because they provide stability to the food web. Without producers, primary consumers
would starve. If their population declines, the secondary consumers would also starve. This would go on until the top predators would starve as
well.
The diagram below shows the parts of a food web and explains why certain organisms are labeled as tertiary, secondary, primary consumers, or
producers. The reef shark is classified as both a tertiary and secondary consumer because it eats both secondary and primary consumers. The
arrows show where the energy is moving throughout the food web.
47
As energy moves up through the trophic levels, up to 90% of energy may be lost as it moves up the trophic levels. Biomass is the measure of
total dry mass of organisms in a given area. An energy pyramid is a diagram that compares energy used by producers, primary consumers, and
other trophic levels. Because so much energy is lost as energy moves through an environment, a large number of producers may only be able to
support a small number of top level consumers. This is also why the top level predators must constantly eat.
SC.912.L.17.10
Objective: Diagram and explain the biogeochemical cycles of an ecosystem, including water, carbon, and nitrogen cycles.
A biogeochemical cycle is the movement of a particular chemical through the biological and geological parts of an ecosystem.
The hydrologic cycle is the circular pathway of water on Earth from the atmosphere, to the surface, below ground, and back. It consists of
precipitation, groundwater, seepage, evaporation, transpiration, and condensation. You will need to be able to label these on a diagram.
Other types of biogeochemical cycles are the oxygen cycle, the carbon cycle, the nitrogen cycle, and the phosphorus cycle.
In the oxygen cycle:
Heterotrophs breathe in oxygen and release carbon dioxide
Photosynthesis in plants causes intake of carbon dioxide and release of oxygen
In the nitrogen cycle:
Bacteria convert N2 to ammonia in a process called nitrogen fixation.
Ammonia released is transformed into ammonium.
48
Nitrification by bacteria changes the ammonium into nitrate, the form best used by plants, used to make amino acids.
Ammonification returns nitrogen to the soil when decomposers break down dead organisms.
In denitrification, nitrogen is returned to the atmosphere.
Bacteria are essential at all parts of the nitrogen cycle.
In the carbon cycle:
Through combustion, the burning of fossil fuels releases carbon dioxide into the atmosphere.
Through respiration and photosynthesis, oxygen and carbon dioxide are exchanged on land and in the water.
Through decomposition, fossil fuels are created.
In the phosphorus cycle:
Phosphate is released by the weathering of rocks.
Phosphate moves through food web and returns to the soil or water during decomposition.
Phosphorus eventually becomes rock again
Chemicals do not move into the atmosphere.
SC.912.L.17.11
Objective: Evaluate the costs and benefits of renewable and nonrenewable resources, such as water, energy, fossil fuels, wildlife, and forests.
A nonrenewable resource is a resource that is used faster than it is formed. Resources that cannot be used up are called renewable resources.
Nonrenewable resources include oil, coal, nuclear energy, etc., while renewable resources include wind energy, solar energy, etc. Each has their
advantages and disadvantages.
The disadvantage of using nonrenewable resources is that it forms at an extremely slow rate and therefore can be used up. The depletion of
fossil fuels may lead to energy crisis’s or even war unless new technologies are developed that use less or no fossil fuels.
While this is a disadvantage with nonrenewable resources, some renewable resources can be used indefinitely. However, if a renewable
resource is used too quickly, it may become a nonrenewable resource.
Sustainable development is the practice in which natural resources are used and managed in a way that meets the current needs without
hurting future generations.
SC.912.L.17.13
Objective: Discuss the need of adequate monitoring of environmental parameters when making policy decisions.
When making policy decisions, the environmental effects of the policy must be considered.
49
The Environmental Protection Agency (EPA) was created in 1970, used to develop policies that protect the environment. Such policies include
the Clean Water Act, the Clean Air Act, and the Endangered Species Act. The government can also protect the environment by setting aside
land, especially through the National Park Service.
SC.912.L.17.15
Objective: Discuss the effects of technology on environmental quality.
Technology can have a positive or negative effect on environmental quality.
Negative effects may come from the use or overuse of hydroelectric dams, vehicle exhaust, factory exhaust, poor waste management, etc.
Positive effects may come from an increase in efficiency of vehicles, etc.
SC.912.L.17.16
Objective: Discuss the large-scale environmental impacts resulting from human activity, including waste spills, oil spills, runoff, greenhouse
gases, ozone depletion, and surface and groundwater pollution.
Greenhouse gases are gases that increase the temperature of the Earth’s atmosphere. The greenhouse effect occurs when carbon dioxide,
water, and methane molecules absorb energy reradiated by Earth’s surface and slow the release of this energy from Earth’s atmosphere. This
may lead to global warming, the trend of increasing global temperatures. Pollutants in the air may also cause acid rain, a type of precipitation
produced when pollutants in the water cycle cause rain pH to drop below normal levels, as a result of nitric acids and sulfur being introduced
into the water cycle.
Pollutants can also affect the hydrosphere. For example, runoff from farms can collect in lakes. The increased nutrition allows for more algae to
grow. The algae can cover the lake and cause the environment beneath it to eventually die off. Groundwater depletion also affects humans. A
major source of water for human consumption can be found underground in aquifers. Pollutants that reach these will also be consumed by
humans.
Surface water pollution may have a large effect on the surrounding environment. If surface water is contaminated, organisms that consume the
water will also be affected. Those organisms higher in the food chain that consume the organism will also contain the toxins. The pollution
affects the top level predator the most. This process is called biomagnification.
SC.912.L.17.18
Objective: Describe how human population size and resource use relate to environmental quality.
Human population size can impact the environment in a variety of ways:
More consumption of resources, such as water
Depletion of non-renewable resources
Use of automobiles leads to global warming
Cutting forests for more land space
Increased pollution
Threatening wildlife and species
Resource use also impact the environment:
Overusing fossil fuels may increase greenhouse gases and increase the global average temperature.
Pollution of natural resources may damage the environment of an organism.
Pollution of air and water may affect organisms’ health.
Lack of sustainable development may have negative long term effects [Easter Island Pg. 486]
SC.912.L.17.19
Objective: Describe how different natural resources are produced and how their rates of use and renewal limit their ability.
One of the main concerns in Biology 1 on how natural resources are formed is the formation of fossil fuels. Fossil fuels are formed by the
decomposition of organisms and the process of moving carbon underground (see carbon cycle). This is a nonrenewable resource that takes
millions of years to form. Because they take so long to form, and humans overuse this resource, the availability of fossil fuels is decreasing
quickly. The increased gas prices at the gas station is a result of this idea.
SC.912.L.17.20
Objective: Predict the impact of individuals on environmental systems and examine how human lifestyles affect sustainability.
Humans may impact environmental systems through pollution and through using up resources. By polluting an area, humans may damage or
impact an environment in a negative manner. Using up resources such as fossil fuels increases air pollution and may harm organisms that use
the air.
Humans impact environmental systems through air and water pollution. For example, runoff from farms may lead to algal blooms in ponds and
lakes, destroying the environment below the surface.
Human lifestyles affect sustainability in a variety of ways. For example, because of the increased use of vehicular transportation, the amount of
air pollution increases. This may kill certain producers. Then, the carrying capacity of all other organisms will decrease as a result.
50
Although humans negatively affect ecosystems, there are positive impacts.
Ability to control population growth rates
Ability to develop technology to produce more food and less waste
Ability to change lifestyles and take action to protect ecosystems
Humans have passed regulations such as the Clean Water Act, the Clean Air Act, and the Endangered Species Act in order to preserve species.
The endangered species act protects endangered animals by preserving their environments. Thus, the endangered species is an umbrella
species because the preservation of that organism leads to the preservation of other organisms within the same ecosystem.
Florida Standard 18: Matter and Energy Transformations
All living things are composed of four basic categories of macromolecules and share the same basic needs for life.
Living organisms acquire the energy they need for life processes through various metabolic pathways (primarily photosynthesis and
cellular respiration).
Chemical reactions in living things follow basic rules of chemistry and are usually regulated by enzymes.
The unique chemical properties of carbon and water make life on Earth possible.
SC.912.L.18.1
Objective: Describe the basic molecular structure and primary functions of the four major categories of biological macromolecules.
Living things are made up of atoms. An atom is the smallest basic unity of matter. An element is a particular type of atom, characterized by the
number of protons. A compound is a substance made up of atoms of different elements bonded together in a certain ratio.
Compounds can form through ionic, covalent bonds, or a combination of both. Two types are ionic and covalent bonds. An ion is an atom that
has gained or lost one or more electrons. An ionic bond is a bond that forms through the attraction of oppositely charged ions. A covalent bond
forms through the sharing of electrons. A molecule is two or more atoms held together by covalent bonds.
Carbohydrates, including starches and sugars, contain C, H, and O in a 1:2:1 ratio. A monomer of a carbohydrate is a monosaccharide. A
polymer of a carbohydrate is a polysaccharide. The function is to provide energy for living things. They can be five carbon sugars or six carbon
sugars.
Lipids are nonpolar molecules that include fats, oils, and cholesterol. The function varies, from comprising part of the cell membrane to storing
energy. They consist of strands or C and H. Unsaturated fats (liquids) do not have an H in every available spot. Saturated fats have an H in every
available spot.
51
Proteins are polymers made up of monomers called amino acids. Amino acids contain a carboxyl group (COOH), amino group (NH2), and an Rgroup. Amino acids only differ in the R group. They are connected to each other by peptide bonds. The function is completely dependent on the
structure of the protein.
Nucleic acids are polymers that are made up of monomers called nucleotides. A nucleotide is composed of a sugar, a phosphate group, and a
nitrogenous base. Two types are DNA and RNA. Its functions are to store genetic information and synthesize proteins.
SC.912.L.18.2
Objective: Describe the important structural characteristics of monosaccharides, disaccharides, and polysaccharides and explain the function of
carbohydrates in living things.
Carbohydrates serve as the primary energy source in living things. Cells break down carbohydrates in order to provide a source of useable
energy for the cell. They are also a part of plant cell structure.
Monosaccharides are simple sugars, including glucose and fructose. Fructose is found in fruits. Glucose is a product of photosynthesis.
A disaccharide is composed of two simple sugars bonded together. One example is table sugar.
Polysaccharides are polymers of carbohydrates, including starches and glycogen. Starch is made and stored in plants; glycogen is made and
stored in animals. Cellulose, another polysaccharide, comprises the cell walls of plant cells.
SC.912.L.18.3
Objective: Describe the structures of fatty acids, triglycerides, phospholipids, and steroids. Explain the function of lipids in living organisms.
Identify some reactions that fatty acids undergo. Relate the structure and function of cell membranes.
Fatty acids contain chains of hydrogen and carbon, including fats, oils, and cholesterol. Lipids can be broken down as a source of energy for
cells. Other lipids maybe part of the cell structure, especially phospholipids.
Two types of lipids are saturated and unsaturated fats. Animal fats and other solid fats are saturated fats, meaning they have the maximum
number of hydrogen atoms as possible. The fatty acid is “saturated” with hydrogen atoms. Oils and other liquid fats are unsaturated because
there are spots that do not contain hydrogen. Animal fats are solid and plant oils are liquids, because the double bonds in unsaturated fats
create kinks in the molecule, so the molecule cannot pack tightly enough to form a solid.
Triglycerides are lipids that contain three fatty acids bonded to a glycerol. Phospholipids consist of glycerol, two fatty acids, and a phosphate
group. Phospholipids make up all cell membranes. They have a polar head and a nonpolar tail.
Steroids contain four rings of carbon atoms. Three of the rings have 6 carbon atoms and one of the rings has 5 carbon atoms. They have many
functions, such as regulating the body’s response to stress, control sexual development, etc.
The relationship between structure and functions of the cell membrane is extremely important. The cell membrane is one of the most
important parts of the cell. It separates the cell from its surroundings and it controls the passage of materials into and out of a cell. Two
methods are endocytosis and exocytosis, both of which are forms of active transport. Because the cell membrane is composed of a double
layered phospholipid, the phospholipid layers of vesicles can merge with that of the cell membrane.
52
The double phospholipid layers allow for easy transport into and out of the cell. In addition, proteins into and on the cell membrane allow for
the communication with other cells and the facilitated diffusion of molecules too large to diffuse through selective permeability. This means
that some molecules can diffuse straight through the membrane (such as water), while some move into and out of the cell through protein
channels.
SC.912.L.18.4
Objective: Describe the structures of proteins and amino acids. Explain the functions of proteins in living organisms. Identify some reactions
that amino acids undergo. Relate the structure and function of enzymes.
Proteins are polypeptides composed of chains of amino acids. The amino acids are connected by a type of covalent bond called a peptide bond.
Amino acids contain a carboxyl group (COOH), an amino group (NH2), and an R-group. Amino acids differ only by the R group. Amino acids
contain hydrogen, oxygen, nitrogen, and sometimes sulfur. While organisms use 20 amino acids, only 12 can be made within the human body.
The other 8 come from foods, such as meat, beans, and nuts.
Proteins are essential to all biological processes. Proteins can have one of several types of functions:
Enzymes: biological catalysts
Structural: make structures rigid or stiff, such as in nails, hair, ligaments, and bone
Antibodies: defense against infection
Specialized
Enzymes are biological catalysts that reduce the activation energy needed to start a chemical reaction. They also increase the rate at which a
chemical reaction occurs. They are necessary because without them, many chemical reactions that take place would require too much
activation energy to begin the process. They allow chemical reactions to occur under to conditions within an organism. Almost all enzymes are
proteins.
An analogy that helps understand enzymes is the lock and key model. The ability of an enzyme to catalyze enzymes is dependent on the shapes
of both the enzyme and the substrates (reactants). Notice that if any of the parts in the diagram below are misshapen, then the reaction would
not be able to occur.
Enzymes can become denatured if the temperature or pH rises or fall too much. This is why a high fever is dangerous. If the conditions vary by
too much, the enzyme can lose its shape and will not work anymore.
SC.912.L.18.6
Objective: Discuss the role of anaerobic respiration in living things and in human society.
An aerobic process needs oxygen to take place. An anaerobic function does not need oxygen to take place.
Examples of anaerobic processes:
Glycolysis splits glucose into two three-carbon molecules and makes 2 molecules of ATP.
Lactic acid fermentation, such as when you feel burning in your legs while running or in your arm while lifting weights
Alcoholic fermentation, such as when yeast make bread or pizza rise as well as in the production of cheese
Fermentation in bacteria in the digestive system of animals.
SC.912.L.18.7
Objective: Identify the reactants, products, and basic functions of photosynthesis.
53
Photosynthesis is an extremely complex process, so this section will be divided into a simplified version and a more complex version.
First, you must understand the vocabulary in order to understand the processes.
Photosynthesis: process that captures energy from sunlight in order to make sugars that store chemical energy.
Chlorophyll: molecule in chloroplasts that absorbs some of the energy in visible light.
Thylakoid: membrane-bound structure within the chloroplasts that contains chlorophyll and other light-absorbing pigments used in
the light-dependent reactions of photosynthesis.
Light-dependent reactions: part of photosynthesis that absorbs energy from sunlight and transfers energy to the light-independent
reactions
Light-independent reactions: part of photosynthesis that uses energy absorbed during the light-dependent reactions to synthesize
carbohydrates.
Photosystem: series of light-absorbing pigments and proteins that capture and transfer energy in the thylakoid membrane.
Electron transport chain: series of proteins in the thylakoid and mitochondrial membranes that aid in converting ADP to ATP by
transferring electrons.
ATP synthase: enzyme that catalyzes the reaction that adds a high-energy phosphate group to ADP to form ATP.
Calvin cycle: process by which a photosynthetic organism uses energy to synthesize simple sugars from CO2.
Simplified version of photosynthesis:
Photosynthesis starts with the light-dependent reactions
Energy from sunlight is absorbed. Water is broken down and oxygen is released.
Energy-carrying molecules, including ATP, transfer energy from the thylakoid to the stroma (fluid outside the thylakoids)
The next part is part of the light-independent reactions
Carbon dioxide molecules are used to build sugars.
A molecule of simple sugars is formed.
The equation for photosynthesis is: 6𝐶𝑂 + 6H O ⎯⎯ C H O +6O
Photosynthesis in more detail:
The process starts in Photosystem 2 of the thylakoid membrane. Please remember that Photosystem 2 comes before Photosystem 1.
Note that a proton is an H+ ion and an electron is an e- ion.
Light-absorbing molecules absorb light in the thylakoid membrane. The energy is transferred to electrons, which then enter the
electron transport chain.
Water molecules are broken down into 2 electrons, 2 protons, and 1 oxygen atom. The oxygen is released as waste. The electrons
“refill” the space where the electron left when it absorbed the Sun’s energy. Electrons move across the electron transport chain. The energy transports the protons from the water molecule across the thylakoid
membrane. These protons came from the water molecules that were broken down earlier.
The remainder of the electron transport chain occurs in Photosystem 1.
The electron being transported across the thylakoid reaches another light-absorbing pigment. This electron then absorbs more
energy from sunlight.
The electron leaves the electron transport chain and is added to a molecule of NADP+. This creates NADPH, an electron carrier.
A proton flows through a protein channel in facilitated diffusion across the thylakoid membrane.
The proton is added to ADP to make ATP.
Congratulations. That was half of the process.
54
Light independent reactions do not need sunlight. The energy sources are ATP and NADPH, which were created in Photosystem 1.
The remainder of the process is the Calvin cycle.
One molecule of carbon dioxide enters at a time.
There is an existing 5-carbon molecule already in the cycle.
1 carbon dioxide enters the system. The carbon bonds with the 5-carbon molecule to form a 6-carbon molecule.
ATP and NADPH split the 6-carbon molecule into two three-carbon molecules.
One three-carbon molecule exits the cycle while one remains. The one that exits is set aside for now.
Carbon dioxide enters the system. 3 CO2 molecules enter the system. The carbons bond to the existing 3-carbon molecule that is still
in the system to create a 6-carbon molecule.
ATP and NADPH add energy and split the 6-carbon molecule into two 3-carbon molecules.
One 3-carbon molecule bonds to the other 3-carbon molecule that we set aside to form a 6-carbon molecule.
The 6-carbon molecule exits the system as a glucose molecule.
The 3-carbon molecule stays in the system. Once again, 3 carbon dioxide molecules enter. The process repeats itself.
The function of photosynthesis is one of the most important processes on Earth. Plants produce food not only for themselves, but also for other
organisms to consume. Photosynthesis also provides materials for plant growth and development. Simple sugars made by photosynthesis are
bonded to create complex carbohydrates. In addition, photosynthesis removes carbon dioxide from Earth’s atmosphere.
SC.912.L.18.8
Objective: Identify the reactants, products, and functions of aerobic and anaerobic cellular respiration.
Like photosynthesis, cellular respiration is also a complex process. The first part of this section will explain cellular respiration in simplified
terms while the second part will explain cellular respiration in a more detailed fashion.
Important vocabulary:
Cellular respiration: process where ATP is produced by breaking down carbon-based molecules when oxygen is present.
Aerobic: process that requires oxygen to occur.
Glycolysis: anaerobic process in which glucose is broken down into two molecules of pyruvate and two net ATP are produced.
Anaerobic: process that does not require oxygen to occur.
Krebs cycle: process during cellular respiration that breaks down a carbon molecule to produce molecules that are used in the
electron transport chain.
Cellular respiration (simplified)
Before cellular respiration starts, Glycolysis occurs. 2 ADP breaks down one glucose molecule into two three-carbon molecules
(pyruvate). This occurs in the cytoplasm and produces 2 ATP. Glycolysis is anaerobic.
Two molecules of pyruvate enter the matrix, the area within the mitochondrial inner membrane.
The Krebs cycle occurs.
For every glucose molecule that enters the process, 6 carbon dioxide molecules are released as waste.
Energy is transferred to the second stage of cellular respiration, the electron transport chain.
The electron transport chain process occurs on the inner membrane, not in the matrix.
Up to 36 ATP are made are made.
The chemical equation for cellular respiration is: C H O +6O
⎯⎯ 6𝐶𝑂 + 6H O.
Cellular respiration in more detail:
Glycolysis comes before cellular respiration, occurs in the cytoplasm, and is anaerobic.
Two ATP energize a glucose molecule, which then splits into two three-carbon molecules.
Energized electrons from the three-carbon molecules are transferred to two molecules of NAD+, forming two NADH. Four ATP are
made.
Glycolysis forms a net two ATP molecules.
The Krebs cycle is the first part of cellular respiration.
First, we assume that a four-carbon molecule is already in the system.
When pyruvate enters the Krebs cycle, the three-carbon molecule is split into a two-carbon molecule and a one-carbon molecule,
given off as CO2. Electrons from the two-carbon molecule transfer to NAD+, which then becomes NADH. The NADH moves to the
electron transport chain.
Coenzyme A bonds to the two-carbon molecule, and enters the Krebs cycle.
Coenzyme A helps bond the two-carbon molecule to the four-carbon molecule already in the cycle. Coenzyme A goes back to the
55
previous step. The six-carbon molecule that is formed is called citric acid.
The citric acid is broken down into a five-carbon molecule and a one-carbon molecule. NADH is made and goes to the electron
transport chain. The one-carbon molecule is released as CO2 waste.
An enzyme breaks down the five-carbon molecule, forming a four-carbon molecule, one molecule of NADH (which goes to the
electron transport chain), one molecule of ATP, and one molecule of carbon dioxide.
The four carbon molecule is rearranged by enzymes, releasing electrons. This makes NADH and FADH2, both of which go to the
electron transport chain.
This is for one molecule of pyruvate. Therefore, for each glucose molecule, this occurs twice. For each glucose molecule that enters
the Krebs Cycle, 6 molecules of carbon dioxide are released as waste, 2 molecules of ATP are made, 8 molecules of NADH are made
and go to the electron transport chain, and 2 molecules of FADH2 molecules are made and go to the electron transport chain.
The electron transport chain comes next.
Electrons are released from the electron carriers NADH and FADH2. There are 12 electrons transferred to this step that were
produced in the Krebs cyle.
The electrons enter the electron transport chain. This allows hydrogen ions (protons) to transport across the inner membrane.
Hydrogen ions build up within the inner mitochondrial membrane.
Hydrogen ions diffuse through ATP synthase, which is used to add phosphate groups to ADP to make ATP.
The electron leaves the electron transport chain. 2 hydrogen ions move through the ATP synthase, and one oxygen molecule is
introduced. They bond to form water. 2 electrons are needed to form one water molecule, so for every two electrons that enter the
electron transport chain, one water molecule is produced.
The function of cellular respiration is to provide energy for living things by breaking down glucose to create ATP. One of the waste products is
carbon dioxide. When we breathe, we exhale the products of cellular respiration. This is one of the reactants used in photosynthesis. Through
photosynthesis, plants can convert the carbon dioxide back into oxygen.
SC.912.L.18.9
Objective: Explain the interrelated nature of photosynthesis and cellular respiration.
The products of one process are the reactants of the other. What we breathe out can be used by plants to produce sugars and the stuff we
breathe in. Cellular respiration needs the products of photosynthesis in order to work. Notice that in the chemical equations of each process,
the chemicals used are the same ones. The only difference between both equations is that whichever side of the yield arrow that a chemical
was on in one process switched sides. For example, 6CO2 was on the left side in photosynthesis but is on the right side of cellular respiration.
In addition, photosynthesis stores energy while cellular respiration releases energy. Photosynthesis creates sugars, which are then stored
within the organism. When the organism needs energy, it can break down these sugars through cellular respiration. The purpose of cellular
56
respiration is to create ATP from sugars.
SC.912.L.18.10
Objective: Connect the role of adenosine triphosphate (ATP) to energy transfers within a cell.
ATP (adenosine triphosphate) is a molecule that transfers energy from the breakdown of food molecules to cell processes. It is the “biological currency” of energy. It is necessary for almost all cellular processes. Adenosine diphosphate (ADP) is a lower-energy molecule that can be
converted into ATP by adding a phosphate group.
The energy that ATP has is located between the 2nd and 3rd phosphate groups. Energy can be stored by adding a phosphate group to ADP. In
contrast, energy can be released and used by breaking the bond between the 2nd and 3rd phosphate groups in ATP.
Carbon-based molecules can be broken down to produce ATP. Carbohydrates and proteins each give about 4 calories per mg, while lipids give
about 9 calories per mg. Lipids, not carbohydrates, provide the most ATP. A triglyceride that is broken down can yield up to 146 ATP.
SC.912.L.18.11
Objective: Explain the role of enzymes as catalysts that lower the activation energy of biochemical reactions. Identify factors, such as pH and
temperature, and their effect on enzyme activity.
A chemical reaction is a process that changes substances into different substances by breaking and forming chemical bonds. Reactants are the
substances changed during a reaction. Products are substances made by a chemical reaction.
Bond energy is the amount of energy needed to break a bond that connects two atoms.
Chemical equilibrium is a state in which both the reactants and products of a chemical reaction are made at the same rate.
Two types of chemical reactions are exothermic and endothermic reactions.
A catalyst is a substance that decreases the activation energy needed to start a chemical reaction. A biological catalyst is known as an enzyme,
usually a protein. They both decrease the activation energy needed to start reactions and increase the rate at which a chemical reaction
progresses. Enzymes are involved in almost every biological process.
The following information is copied from standard SC.912.L.184
Enzymes are biological catalysts that reduce the activation energy needed to start a chemical reaction. They also increase the rate at which a
chemical reaction occurs. They are necessary because without them, many chemical reactions that take place would require too much
activation energy to begin the process. They allow chemical reactions to occur under to conditions within an organism. Almost all enzymes are
57
proteins.
An analogy that helps understand enzymes is the lock and key model. The ability of an enzyme to catalyze enzymes is dependent on the shapes
of both the enzyme and the substrates (reactants). Notice that if any of the parts in the diagram below are misshapen, then the reaction would
not be able to occur.
Enzymes can become denatured if the temperature or pH rises or fall too much. This is why a high fever is dangerous. If the conditions vary by
too much, the enzyme can lose its shape and will not work anymore.
SC.912.L.18.12
Objective: Discuss the special properties of water that contribute to Earth’s sustainability as an environment for life: cohesive behavior, ability
to moderate temperature, expansion upon freezing, and versatility as a solvent.
Water is a polar molecule composed of an oxygen molecule and two hydrogen molecules. The bonds that keep the molecule intact are covalent
bonds. One of water’s special properties is its polarity. The oxygen molecule is slightly negative and the hydrogen atoms are slightly positive
because the electrons are closer to the oxygen atom.
Because water molecules are polar molecules, the positive ends on one molecule can interact with the negative end on another molecule. A
bond that forms between a slightly positive hydrogen atom and a slightly negative oxygen or nitrogen atom is called a hydrogen bond. A water
molecule can form up to four hydrogen bonds.
Water’s ability to form hydrogen bonds allows for several other properties to exist.
Hydrogen bonds allow water to resist temperature change, causing water to have a high specific heat. Therefore, more energy must be added
to water in order to increase the temperature. Within cells, chemical reactions can release a large amount of heat. Water can absorb this heat
and prevent overheating within the cell.
Cohesion is the attraction among molecules of a substance. Adhesion is the attraction among molecules of different substances. Hydrogen
bonding allows for water molecules to stick to themselves. If you’ve ever seen an insect “walk” on water, this is a result of cohesion producing surface tension. Adhesion is important in plants. It helps the plant transport water up the xylem, against gravity. This is because water
molecules stick to the walls of the xylem. In addition, cohesion holds the water together as it travels up the stems of plants.
A property of water that is not related to polarity is its ability to dissolve many substances. Many substances cannot perform their functions in
cell processes or be transported unless they are dissolved. A solution is a mixture in which one substance dissolves in another. The solvent is
greater in volume and dissolves the other substance. The solute is the substance being dissolved. In salt water, the water is the solvent and the
salt is the solute. Within living things, water is the solvent.
Polar substances dissolve in other polar substances (such as water), while nonpolar substances rarely dissolve in water. This is why oil never
dissolves in water.
Water has a pH of 7. A pH 7 is neutral. A pH level lower than 7 is acidic. A pH greater than 7 is basic. Most organisms require a neutral pH.
However, some organisms survive in extremely basic or extremely acidic environments. PH is regulated in organisms through buffers. A buffer is
a compound that can bind to an H+ ion (a proton) when the concentration is large and can release a proton when the concentration is low. If
the pH is too high or too low, it can be deadly, because it disrupts cell processes.
Just some additional information (you don’t really need to know this for the EOC): The pH scale is based on a logarithmic scale (for those in
Algebra 2 or above). [𝑝𝐻 = −log(𝐻 𝐶𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛)]. This means that a pH of 14 is 10 times more basic and 10 times less acidic than a pH of
13. A pH of 3 is 10 times more acidic than a pH of 4. A pH of 7 is 100 times more basic than a pH of 5, etc.
58
59
Vocabulary
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
Abiotic: Nonliving factor in an ecosystem, such as moisture, temperature, wind, sunlight, soil, and minerals.
Abyssal Zone: Depth of the ocean that lies below 2000 meters and is in complete darkness.
Acid Rain: Precipitation produced when pollutants in the atmosphere cause the pH of rain to decrease.
Acid: Compound that donates a proton when dissolved in a solution
Activation Energy: Energy input necessary to initiate a chemical reaction.
Active Immunity: Immunity that occurs after the body responds to an antigen.
Active Transport: Energy-requiring movement of molecules across a membrane from a region of lower concentration to a region of higher
concentration.
Adaptation: Inherited trait that is selected for over time because it allows organisms to better survive in their environment.
Adaptation: Inherited trait that is selected for over time because it allows organisms to better survive in their environment.
Adaptive Radiation: process by which one species evolves and gives rise to many descendant species that occupy different ecological niches.
Adenosine Diphosphate: Low energy molecule that can be converted to ATP.
Adenosine Triphosphate: High-energy molecule that contains energy that cells can use within its bonds.
Adhesion: Attraction between molecules of different substances.
Adolescence: Period of life beginning at puberty and ending at adulthood.
Adulthood: Period of life when a person is fully developed and physical growth stops.
Aerobic: Process that requires oxygen to occur.
AIDS: Final stage of the immune system’s decline due to HIV.
Algae: Photosynthetic plantlike protists.
Alkaloid: Chemical produced by plants that contains nitrogen, many of which are used in medicines.
Allele Frequency: Proportion of one allele, compared with all the alleles for that trait, in the gene pool.
Allele: Any of the alternative forms of a gene that occurs at a specific place on a chromosome.
Alternation of Generations: plant life cycle in which the plant alternates between haploid and diploid phases.
Amniotic Sac: Fluid-filled organ that cushions and protects the developing embryo of some vertebrates.
Anaerobic: Process that does not require oxygen to occur.
Analogous structure: Body part that is similar in function as a body part of another organism but is structurally different.
Anaphase: Third phase of mitosis during which chromatids separate and are pulled to opposite sides of the cell.
Angiosperm: Seed plant whose embryos are enclosed by fruit.
Anthropoid: Humanlike primate.
Antibiotic Resistance: Process by which bacteria mutate so that they are no longer affected by an antibiotic.
Antibiotic: Chemical that kills or slows the growth of bacteria.
Antibody: Protein produced by B cells that aid in the destruction of pathogens.
Anticodon: Set of three nucleotides in a tRNA molecule that binds to a complementary mRNA codon during translation.
Antigen: Protein marker that helps the immune system identify foreign particles.
Antiseptic: Chemical, such as soap, vinegar, or rubbing alcohol, that destroys pathogens outside the body.
Apoptosis: Programmed cell death.
Archaea: one of three domains of life, containing unicellular prokaryotes in the Kingdom Archaea.
Artery: Large blood vessel that carries blood away from the heart.
Artificial Selection: Process by which humans modify a species by breeding it for certain traits.
Asexual Reproduction: Process by which offspring are produced from a single parent; does not involve the joining of egg and sperm.
Atmosphere: Air blanketing Earth’s solid surface.
Atom: Smallest basic unit of matter.
ATP Synthase: Enzyme that catalyzes the reaction that adds a high-energy phosphate group to ADP to form ATP.
Atrium: Small chamber in the human heart that receives blood from the veins.
Autonomic Nervous System: Division of the peripheral nervous system that controls involuntary functions.
Autosome: Chromosome that contains genes for characteristics not directly related to the sex of the organism.
Autotroph: Organism that obtains its energy from abiotic sources, such as sunlight or inorganic chemicals.
Bacteria: one of three domains of life, containing unicellular prokaryotes in the Kingdom Bacteria.
Bacteriophage: Virus that infects bacteria.
Base Pairing Rules: Rule that describes how nucleotides form bonds in DNA; adenine always bonds with thymine and guanine always bonds
with cytosine.
Base: Compound that accepts a proton when dissolved in a solution.
Bathyal Zone: Zone of the ocean that extends from the edge of the neritic zone to the base of the continental shelf.
B-Cell: White blood cell that matures in the bone marrow and produces antibodies that fight off infection; also called a B-lymphocyte.
Behavioral Isolation: Isolation between populations due to differences in courtship or mating behavior.
Benign: Having no dangerous effect on health, especially referring to an abnormal growth of cells that are not cancerous.
60
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
99.
100.
101.
102.
103.
104.
105.
106.
Benthic Zone: Lake or pond bottom, where little to no sunlight can reach.
Bilateral Symmetry: Body plan of some organisms in which the body can be divided equally along only one plane.
Binary Fission: Asexual reproduction in which a single-celled organism divides into two equal parts.
Binomial Nomenclature: a system that gives each species a two part scientific name using Latin words.
Biodiversity: Variety of life within an area.
Biodiversity: Variety of life within an area.
Biogeochemical Cycle: Movement of a chemical through the biological and geological, or living and nonliving, parts of an ecosystem.
Biogeography: Study of the distribution of organisms around the world.
Bioinformatics: Use of computer databases to organize and analyze biological data.
Biology: Scientific study of all forms of life.
Biomagnification: Condition of toxic substances being more concentrated in tissues of organisms higher on the food chain than ones lower in
the food chain.
Biomass: Total dry mass of all organisms in a given area.
Biome: Regional or global community or organisms characterized by the climate conditions and plant communities that thrive there.
Biosphere: All organisms and the part of Earth where they exist.
Biosphere: All organisms and the part of Earth where they exist.
Biota: Collection of living things.
Biotechnology: The use and application of living things and biological processes.
Biotic: Living things, such as plants, animals, fungi, and bacteria, as well as once living things.
Bipedal: Animal that walks on two legs.
Blade: broad part of a leaf where most of the photosynthesis takes place.
Blastocyst: Stage of development during which the zygote consists of a ball of cells.
Blood Pressure: Force with which blood pushes against the wall of an artery.
Bond Energy: Amount of energy needed to break a bond between two particular atoms; or the amount of energy when a bond forms between
two particular atoms.
Botany: The study of plants.
Bottleneck Effect: Genetic drift that results from an event that drastically reduces the size of a population.
Brain Stem: Structure that connects the brain to the spinal cord and controls breathing and heartbeat.
Calvin Cycle: Process by which a photosynthetic organism uses energy to synthesize simple sugars from CO2.
Cancer: Common name for a class of diseases characterized by uncontrolled cell division.
Canopy: Dense covering formed by the uppermost branches of trees.
Capillary: Tiny blood vessel that transports blood between larger blood vessels and other tissues in the body.
Capsid: Protein shell that surrounds a virus.
Carbohydrate: Molecule composed of carbon, hydrogen, and oxygen; includes sugars and starches.
Carcinogen: Substance that causes cancer.
Carnivore: Organism that obtains energy by eating only animals.
Carpel: female structure of flowering plants; made of the ovary, style, and stigma.
Carrier: Organism whose genome contains a gene for a certain trait or disease that is not expressed in the organism’s phenotype.
Carrying Capacity: Number of individuals that the resources of an environment can normally and persistently support.
Catalyst: A substance that decreases activation energy and increases the reaction rate in a chemical reaction.
Catastrophism: theory that states that natural disasters such as floods and volcanic eruptions shaped Earth’s landforms and caused extinctions of some species.
Cell Cycle: Pattern of growth, DNA replication, and cell division that occurs in a eukaryotic cell.
Cell Differentiation: Processes by which unspecified cells develop into their mature form and function.
Cell Membrane: A double layer of phospholipids that forms a boundary between a cell and the surrounding environment and controls the
passage of materials into and out of a cell.
Cell Theory: The theory that states that all organisms are made of cells, all cells are produced by other living cells and the cell is the basic unit
of life.
Cell Wall: Rigid structure that gives protection, support, and shape to cells in plants, algae, fungi, and bacteria.
Cell: Basic unit of life.
Cellular Immunity: Immune response that relies on T cells to destroy infected body cells
Cellular Respiration: Process of producing ATP by breaking down carbon-based molecules when oxygen is present.
Central Dogma: Theory that states that, in cells, information only flows from DNA to RNA to proteins.
Central Nervous System: Part of the nervous system that interprets messages from other nerves in the body, including the brain and spinal
cord.
Centriole: A small, cylinder-shaped organelle made of protein tubes arranged in a circle; aids mitosis.
Centromere: Part of a condensed chromosome that looks pinched; where spindle fibers attach during meiosis and mitosis.
Cerebellum: Part of the brain that coordinates and regulates all voluntary muscle movement and maintains posture and balance.
61
107. Cerebral Cortex: Layer of grey matter on the surface of the cerebrum that receives information and generates responses.
108. Cerebrum: Largest part of the brain, coordinating movement, thought, reasoning, and memory, including the cerebral cortex and the white
matter beneath it.
109. Chaparral: Biome characterized by hot, dry summers and cool, moist winters; also called Mediterranean shrub-land.
110. Chemical Reaction: Process by which substances change into different substances through the breaking and forming of chemical bonds.
111. Chemosynthesis: Process by which ATP is synthesized by using chemicals as an energy source instead of light.
112. Chemosynthesis: Process by which ATP is synthesized using chemicals as an energy source instead of light.
113. Childhood: Period of life from age 2 until puberty.
114. Chlorophyll: Light-absorbing pigment molecule in photosynthetic organisms.
115. Chloroplast: Organelle composed of numerous membranes that are used to convert solar energy into chemical energy; contains chlorophyll.
116. Chromatid: One half of a duplicated chromosome.
117. Chromatin: Loose combination of DNA and proteins that is present during interphase.
118. Chromosome: Long continuous thread of DNA that consists of numerous genes and regulatory information.
119. Cilia: Short, hairlike structures that cover some or the entire cell surface and help the organism swim and capture food.
120. Circulatory System: Body systems that transports nutrients and wastes between various body tissues; including heart, blood, and blood
vessels.
121. Cladistics: method of organizing species by evolutionary relationships in which species are grouped according to the order that they diverged
from their ancestral line.
122. Cladogram: a diagram that displays proposed evolutionary relationships among a group of species.
123. Climate: Average long-term weather pattern of a region.
124. Clone: Genetically identical copy of a single gene or an entire organism.
125. Co-Dominance: Heterozygous genotype that equally expresses the traits from both alleles.
126. Codon: Sequence of three nucleotides that codes for one amino acid.
127. Coevolution: Process in which two or more species evolve in response to changes in each other.
128. Cohesion: Attraction between molecules of the same substance.
129. Cohesion-tension theory: theory that explains how the physical properties of water allow it to move through the xylem of plants.
130. Collagen: Three-stranded protein, unique to animals, that combines to form strong, flexible fibers.
131. Collenchyma Cell: elongated cells with unevenly thick walls that form a supportive tissue of plants.
132. Commensalism: Ecological relationship in which one species receives benefit but the other species is not affected one way or another.
133. Community: Collection of all the different populations that live in one area.
134. Competition: Ecological relationship in which two organism attempt to obtain the same resource.
135. Competitive Exclusion: Theory that states that no two species can occupy the same niche at the same time.
136. Compound: Substance made of atoms of different elements that are bonded together in a particular ratio.
137. Concentration Gradient: The difference in the concentration of a substance from one location to another.
138. Cone: Reproductive structure of gymnosperms inside of which the female gamete is fertilized and seeds are produced.
139. Coniferous: Tree that retains its needles year-round and reproduces with cones.
140. Conjugation: Process by which a prokaryote transfers part of its chromosome to another prokaryote.
141. Constant: Condition that is controlled so that it does not change during an experiment.
142. Consumer: Organism that obtains its energy and nutrients by eating other organisms.
143. Convergent Evolution: Evolution toward similar characteristics in unrelated species, resulting from adaptations to similar environmental
conditions.
144. Coral Reef: Ocean habitat found in shallow coastal waters in a tropical climate.
145. Corpus Luteum: Follicle after ovulation, aka a yellow body due to its color.
146. Cotyledon: Embryonic leaf inside of a seed.
147. Covalent Bond: Chemical bond formed when two atoms share one or more pairs of electrons.
148. Cross: Mating of 2 organisms.
149. Crossing Over: Exchange of chromosome segments between homologous chromosomes during meiosis 1.
150. Cuticle: In plants, a waxy layer that holds in moisture.
151. Cyanobacteria: Bacteria that can carry out photosynthesis.
152. Cytokinesis: Process by which the cell cytoplasm divides.
153. Cytoplasm: Jelly like substance inside cells that contains molecules and in some cells organelles.
154. Cytoskeleton: Network of proteins, such as microtubules and microfilaments, inside a eukaryotic cell that supports and shapes the cell.
155. Data: Observations and measurements recorded during an experiment.
156. Deciduous: Tree that has adapted to winter temperatures by dropping its leaves and going dormant during the cold season.
157. Decomposer: Detrivore that breaks down organic matter into simpler compounds, returning nutrients back into an ecosystem.
158. Density-dependent Limiting Factor: Environmental resistance that affects a population that has become overly crowded.
159. Density-independent Limiting Factor: Environmental resistance that affects a population regardless of population density.
160. Dependent Variable: Experimental data collected through observation and experiment.
62
161. Derived Characters: a trait that differs in structure or function from that found in the ancestral line for a group of species, used in constructing
cladograms.
162. Dermal Tissue: tissue system that covers the outside of plants and animals.
163. Desert: Biome characterized by a very dry climate.
164. Detrivore: Organism that eats dead organic matter.
165. Diastolic Pressure: Pressure in an artery when the left ventricle relaxes.
166. Dicot: Flowering plant whose embryos have two cotyledons.
167. Diffusion: Movement of dissolved molecules in a fluid or gas from a region of higher concentration to a region of lower concentration.
168. Dihybrid Cross: Cross between organism involving two pairs of contrasting traits.
169. Diploid: Cell that has two copies of each chromosome, one from an egg and one from a sperm.
170. Directional Selection: Pathway of natural selection in which one uncommon phenotype is selected over a more common phenotype.
171. Disruptive Selection: Pathway of natural selection in which two opposite, but equally uncommon, phenotypes are selected over the most
common phenotype.
172. Divergent Evolution: Evolution of one or more closely related species into different species; resulting from adaptations to different
environmental conditions.
173. DNA Fingerprint: Unique sequence of DNA base pairs that can be used to identify a person at the molecular level.
174. DNA Microarray: Research tool used to study gene expression.
175. DNA Polymerase: Enzyme that makes bonds between nucleotides, forming and identical strand of DNA during replication.
176. DNA: Molecule that stores genetic information in all organisms.
177. Dominant: Allele that is expressed when two different alleles are present in an organism’s genotype.
178. Dormancy: State of inactivity during which an organism or embryo is not growing.
179. Double Fertilization: Process by which two sperm of a flowering plant join with an egg and a polar body, forming an embryo and endosperm.
180. Double Helix: Model that compares the structure of a DNA molecule, in which the two strands wind around one another, to that of a twisted
ladder.
181. Ecological Equivalent: Organisms that share a similar niche but live in different geographical regions.
182. Ecological Footprint: Amount of land necessary to produce and maintain enough food, water, shelter, energy, and waste.
183. Ecological Niche: All of the physical, chemical, and biological factors that a species needs to survive, stay healthy, and reproduce in an
ecosystem.
184. Ecology: The study of the interactions of livings and their surroundings.
185. Ecosystem: Collection of organisms and nonliving things, such as climate, soil, water, and rocks, in an area.
186. Ecosystem: Collection of organisms and nonliving things, such as climate, soil, water, and rocks, in an area.
187. Egg: Female gamete.
188. Electron Transport Chain: Series of proteins in the thylakoid and mitochondrial membranes that aid in converting ADP to ATP by transferring
electrons.
189. Element: Substance made of only one type of atom that cannot be broken down by chemical means.
190. Embryo: Stage of development after the fertilized cell implants into the uterus but before the cells take on a recognizable shape.
191. Emigration: Movement of individuals out of a population.
192. Endocytosis: Uptake of liquids or large molecules into a cell by inward folding of the cell membrane.
193. Endometrium: Lining of the uterus.
194. Endoplasmic reticulum: Interconnected network of thin, folded membranes that produce, process, and distribute proteins.
195. Endosperm: tissue within seeds of flowering plants that nourishes an embryo.
196. Endospore: Prokaryotic cell with a thick, protective wall surrounding its DNA.
197. Endosymbiosis: Ecological relationship in which one organism lives within the body of another.
198. Endothermic: Chemical reaction that requires a net input of energy.
199. Energy Pyramid: Diagram that compares energy used by producers, primary consumers, and other tropic levels.
200. Enzyme: Protein that catalyzes chemical reactions for organisms.
201. Epidemic: Rapid outbreak of a disease that affects many people.
202. Epididymis: Coiled tube through which the sperm leave the testes and enter the vas deferens.
203. Equilibrium: Condition in which the reactants and the products of a chemical reaction are formed at the same rate.
204. Estrogen: Steroid hormone that is found in greater quantities in women than men and contributes to female sexual characteristics and
development.
205. Estuary: Partially enclosed body of water found where a river flows into the ocean.
206. Eukarya: one of three domains of life, containing all Eukaryotes in Kingdoms Protista, Plantae, Fungi, and Animalia.
207. Eukaryotic cell: A cell with a nucleus and other membrane-bound organelles.
208. Evolution: Change in a species over time; process of biological change by which descendents come to differ from their ancestors.
209. Evolution: Change in a species over time; process of biological change by which descendants come to differ from their ancestors.
210. Exocytosis: Release of a substance out of a cell by the fusion of a vesicle with the membrane.
211. Exon: Sequence of DNA that codes information for protein synthesis.
63
212.
213.
214.
215.
216.
217.
218.
219.
220.
221.
222.
223.
224.
225.
226.
227.
228.
229.
230.
231.
232.
233.
234.
235.
236.
237.
238.
239.
240.
241.
242.
243.
244.
245.
246.
247.
248.
249.
250.
251.
252.
253.
254.
255.
256.
257.
258.
259.
260.
261.
262.
263.
264.
265.
266.
267.
Exothermic: Chemical reaction that yields a net release of energy in the form of heat.
Experiment: Process that tests a hypothesis by collecting information under controlled conditions.
Exponential Growth: Dramatic increase in population over a short period of time.
Extinction: Elimination of a species from Earth.
Facilitated Diffusion: Diffusion of molecules assisted by protein channels that pierce a cell membrane.
Fallopian Tube: Tube of connective tissue that attaches the ovary to the uterus in the female reproductive system and in which fertilization
occurs.
Fatty Acid: Hydrocarbon chain often bonded to glycerol in a lipid.
Fermentation: Anaerobic process by which ATP is produced by Glycolysis.
Fertilization: Fusion of a sperm and egg.
Fetus: Unborn offspring from the end of the eight week after conception to the moment of birth.
Fibrous root: root system made up of many threadlike members of more or less equal strength.
Fitness: Measure of an organism’s ability to survive and produce offspring relative to other members of a population.
Flower: Female reproductive structure of an angiosperm.
Fluid Mosaic Model: Model that describes the arrangement and movement of the molecules that make up a cell membrane.
Follicle: A collection of cells that surrounds and nourishes an egg while it is the ovary.
Food Chain: Model that links organisms by their feeding relationships.
Food Web: Model that shows the complex network of feeding relationships within an ecosystem.
Fossil: Trace of an organism from the past.
Founder Effect: Genetic drift that occurs after a small number of individuals colonize a new area.
Frameshift Mutation: Mutation that involves the insertion or deletion of a nucleotide in the DNA sequence.
Fruit: Fertilized and mature ovary of a flower.
Gamete: A sperm or egg.
Gametogenesis: Process by which gametes are produced through the combination of meiosis and other maturational changes.
Gametophyte: haploid, gamete-producing phase in a plant life cycle.
Gel Electrophoresis: Method of separating various lengths of DNA strands by applying an electrical current to a gel.
Gene Flow: Physical movement of alleles from one population to another.
Gene Knockout: Genetic manipulation in which one or more of an organism’s genes are prevented from being expressed.
Gene Pool: Collection of alleles found in all of the individuals of a population.
Gene Sequencing: Process of determining the order of DNA nucleotides in genes and genomes.
Gene Therapy: Procedure to treat a disease in which a defective or missing gene is replaced or a new gene is inserted into a patient’s genome.
Gene: Specific region of DNA that codes for a particular protein.
Gene: Specific region of DNA that codes for a particular protein.
Generalist: Species that does not rely on a single source of prey.
Genetic Drift: Change in the allele frequencies due to chance alone, occurring mostly in small populations.
Genetic Engineering: Process of changing an organism’s DNA to give the organism new traits.
Genetic Linkage: Tendency for genes located together on the same chromosome to be inherited together.
Genetic Screening: Process of testing DNA to determine the chance a person has, or might pass on, a disorder.
Genetics: Study of the heredity patterns and variation of organisms.
Genome: All of an organism’s genetic material.
Genomics: Study and comparison of genomes within a single species or among different species.
Genomics: Study and comparison of genomes within a single species or among different species.
Genotype: Collection of all of an organism’s genetic information that codes for traits.
Genus: the first name in binomial nomenclature; the second-most specific taxon in the Linnaean classification system that includes one or
more physically similar species, thought to be closely related.
Geographic Isolation: Isolation between populations due to physical barriers.
Geosphere: Features of Earth’s surface, such as continents and the sea floor - and everything below Earth’s surface.
Germ theory: Theory that states that diseases are caused by microscopic particles called pathogens.
Germination: Process by which seeds or spores sprout and begin to grow.
Global Warming: Worldwide trend of increasing average temperatures.
Glycolysis: Anaerobic process in which glucose is broken down into two molecules of pyruvate and two net ATP are produced.
Golgi Apparatus: A stack of flat, membrane-enclosed spaces containing enzymes that process, sort, and deliver proteins.
Gradualism: Principle that states that the changes in landforms result from slow changes over a long period of time.
Grassland: Biome in which the primary plant life is grass.
Greenhouse Effect: Normal warming effect produced when gases, such as carbon dioxide and methane, trap heat in Earth’s atmosphere.
Ground Tissue: tissue system that makes up the majority of a plant.
Growth Factor: Broad group of proteins that stimulate cell division.
Guard Cell: one pair of cells that controls the opening and closing of a stoma in plant tissue.
64
268.
269.
270.
271.
272.
273.
274.
275.
276.
277.
278.
279.
280.
281.
282.
283.
284.
285.
286.
287.
288.
289.
290.
291.
292.
293.
294.
295.
296.
297.
298.
299.
300.
301.
302.
303.
304.
305.
306.
307.
308.
309.
310.
311.
312.
313.
314.
315.
316.
317.
318.
319.
320.
321.
322.
Gymnosperm: Seed plant whose seeds are not enclosed by fruit.
Habitat Fragmentation: Process by which part of an organism’s preferred habitat range becomes inaccessible.
Habitat: Combined biotic and abiotic factors found in the area where an organism lives.
Half-Life: Amount of time it takes for half of the isotope in a sample to decay into its product isotope.
Haploid: Cell that only has one copy of each chromosome.
Hardy-Weinberg Equilibrium: Condition in which a population’s allele frequencies for a given trait do not change from one generation to generation.
Heart: Muscle in the chest that moves blood throughout the body.
Herbivore: Organism that eats only plants.
Heritability: Ability of a trait to be passed from one generation to the next.
Heterotroph: Organism that obtains its energy and nutrients by consuming other organisms.
Heterozygous: Characteristic of having two different alleles that appear at the same locus of sister chromatids.
Histone: Protein that organizes chromosomes and around which DNA wraps.
HIV: Retrovirus that attacks and weakens the immune system.
Homeobox: Genes that define the head-to-tail pattern of development in animal embryos; also called Hox genes.
Homeostasis: Regulation and maintenance of constant internal conditions in an organism.
Homeotic: Genes that control early development in animals.
Hominid: Primate that walks upright has long lower limbs, thumbs that oppose the other four fingers, and a relatively large brain.
Homologous Chromosome: Chromosomes that have the same length, appearance, and copies of genes, although the alleles may differ.
Homologous structure: Body part that is similar in structure on different organisms but performs different functions.
Homozygous: Characteristic of having two of the same alleles at the same locus of sister chromatids.
Human Genome Project: Project whose goal is to map, sequence, and identify all of the genes in the human genome.
Humoral Immunity: Immune response that relies on B cells to produce antibodies to help fight infection.
Hydrogen Bond: Attraction between a slightly positive hydrogen atom and a slightly negative atom.
Hydrologic Cycle: Pathway of water from the atmosphere to Earth’s surface, below ground, and back.
Hydrosphere: Collection of Earth’s water bodies, ice, and water vapor.
Hypertonic: Solution that has a higher concentration of dissolved particles compared with another solution.
Hypothesis: Proposed explanation or answer to a scientific question.
Hypotonic: Solution that has a lower concentration of dissolved particles compared with another solution.
Immigration: Movement of individuals into a population.
Immune System: Body system that fights off infections.
Incomplete Dominance: Heterozygous phenotype that is a blend of the two homozygous phenotypes.
Independent Variable: Condition or factor that is manipulated by a scientist during an experiment.
Indicator Species: Species whose presence in an ecosystem gives clues about the condition of that ecosystem.
Infancy: Period of life from birth until the ability to walk has been acquired.
Infertility: Persistent condition in which offspring cannot be produced.
Inflammation: Nonspecific response characterized by swelling, redness, pain, itching, and warmth at the affected site.
Interferon: Type of protein, produced by body cells, that prevents viruses from replicating in infected cells.
Intertidal Zone: Strip of land between high and low tide lines.
Introduced Species: Species that is not native and was brought to an area as a result of human activities.
Intron: Segment of a gene that does not code for an amino acid.
Invertebrate: Animal without a backbone.
Ion: Atom that has gained or lost one or more electrons.
Ionic Bond: Chemical bond formed through the electrical force between oppositely charged ions.
Isotonic: Solution that has an equal concentration of dissolved particles compared with another solution.
Isotope: Form of an element that has the same number of protons but a different number of neutrons as another element.
Karyotype: Image of all the chromosomes in a cell.
Kelp Forest: Ocean habitat that exists in cold, nutrient-rich shallow coastal waters composed of large communities of kelp and seaweed.
Keystone Species: Organism that has an unusually large effect on its ecosystem.
Krebs Cycle: Process during cellular respiration breaks down a carbon molecule to produce Molecules that are used in the electron transport
chain.
Lactic Acid: Product of fermentation in many types of cells, including human muscle cells.
Law of Independent Assortment: Mendel’s second law, stating that allele pairs separate from one another during gamete formation.
Law of Segregation: Mendel’s first law, stating that (1) organisms inherit two copies of genes, one from each parent, and (2) organisms donate
only one copy of each gene in their gametes because the genes separate during gamete formation.
Leukemia: Cancer of the bone marrow.
Lichen: Fungus that grows symbiotically with algae, resulting in a composite organism that grows on rocks or tree trunks.
Light Dependent Reactions: Part of photosynthesis that absorbs energy from sunlight and transfers energy to the light-independent reactions.
65
323. Light Independent Reactions: Part of photosynthesis that uses energy absorbed during the light dependent reactions to synthesize
carbohydrates.
324. Lignin: Complex Polymer that hardens the cell walls of some vascular tissues in plants.
325. Limiting Factor: Environmental factor that limits the growth and size of a population.
326. Limnetic Zone: Open water of a lake or pond that is located away from shore.
327. Linkage Map: Diagram that shows the relative locations of genes on a chromosome.
328. Lipid: Nonpolar molecule composed of carbon, hydrogen, and oxygen, including fats and oils.
329. Littoral Zone: Area between the high and low water marks along the shoreline of a lake or pond.
330. Logistic Growth: Population growth is characterized by a period of slow growth, followed by a period of exponential growth, followed by
another period of almost no growth.
331. Lysosome: Organelle that contains enzymes.
332. Malignant: Cancerous tumor in which cells break away and spread to other parts of the body, causing harm to the organism's health.
333. Meiosis: Form of nuclear division that divides a diploid cell into haploid cells; important in forming gametes for sexual reproduction.
334. Memory Cell: Specialized white blood cell that contributes to acquired immunity by acting quickly to a foreign substance.
335. Menopause: Period of life when the female reproductive system permanently stops the menstrual cycle.
336. Menstrual Cycle: Series of changes in the female reproductive system that takes place over the course of one month.
337. Meristem: undifferentiated plant tissue from which new cells are formed.
338. Mesophyll: photosynthetic tissue of a leaf, located between the upper and lower epidermis.
339. Messenger RNA: Form of RNA that carries genetic information from the nucleus to the cytoplasm, where it serves as a template for protein
synthesis.
340. Metabolism: All chemical processes that synthesize or break down materials within an organism.
341. Metaphase: Second phase of mitosis when spindle fibers line up the chromosomes along the cell equator.
342. Metastasize: To spread by transferring a disease-causing agent from the site of the disease to other parts of the body.
343. Microclimate: Climate of a specific location within a larger area.
344. Microevolution: Observable change in the allele frequencies of a population over a few generations.
345. Microscope: Tool that provides an enlarged image of an object.
346. Mitochondrion: bean-shaped organelle that supplies energy to the cell and has its own ribosomes and DNA.
347. Mitosis: Process by which a cell divides its nucleus and contents.
348. Molecular Genetics: Study of DNA and function on the molecular level.
349. Molecule: Two or more atoms held together by covalent bonds; not necessarily a compound.
350. Monocot: Flowering plant whose embryos have one cotyledon.
351. Monohybrid Cross: Cross between organisms that involve only one pair of contrasting traits.
352. Monomer: Molecular subunit of a polymer.
353. Mutagen: Agent that can induce or increase the frequency of mutations in organisms.
354. Mutation: Change in the DNA sequence.
355. Mutualism: Ecological relationship between two species in which each species gets a benefit from the interaction.
356. Natural Selection: Mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do
other individuals.
357. Nebula: Rotating cloud of gas and dust.
358. Neritic Zone: Zone of the ocean that extends from the intertidal zone out to the edge of the continental shelf.
359. Nitrogen Fixation: Process by which certain types of bacteria convert gaseous nitrogen into nitrogen compounds.
360. Nonrenewable Resource: Natural resource that is used more quickly than it can be formed.
361. Normal Distribution: Distribution in a population in which allele frequency is highest near the mean range value and Decreases progressively
toward each extreme end.
362. Nucleic Acid: Polymer of nucleotides; the genetic material of organisms.
363. Nucleotide: Monomer that forms DNA and has a phosphate group, a sugar, and a nitrogen-containing base.
364. Nucleus: Organelle with a double membrane and stores most of a cell’s DNA. 365. Observation: Using the senses to study the world; using tools to collect measurements; examining previous research results.
366. Omnivore: Organism that eats both plants and animals.
367. Operon: Section of DNA that contains all of the code to begin translation, regulate transcription, and build a protein; includes a promoter,
regulatory gene, and structural gene.
368. Opportunistic Infection: Infection caused by a pathogen that a healthy immune system would normally be able to fight off.
369. Organ System: Two or more organs that work in a coordinated way to carry out similar functions.
370. Organ: Group of different types of tissue that work together to perform a specific function or related functions.
371. Organelle: membrane-bound structure that is specialized to perform a distinct process within the cell.
372. Organism: Any individual living thing.
373. Osmosis: The diffusion of water across a semi-permeable membrane from an area of higher concentration to an area of lower concentration.
374. Ovary: organ in which female gametes develop prior to fertilization.
66
375.
376.
377.
378.
379.
380.
381.
382.
383.
384.
385.
386.
387.
388.
389.
390.
391.
392.
393.
394.
395.
396.
397.
398.
399.
400.
401.
402.
403.
404.
405.
406.
407.
408.
409.
410.
411.
412.
413.
414.
415.
416.
417.
418.
419.
420.
421.
422.
423.
424.
425.
426.
427.
428.
429.
430.
431.
Ovary: Organ in which female gametes develop prior to fertilization.
Ovulation: Process by which an egg is released from the ovary and is available for fertilization.
Ovum: Egg cell that is produced by the female reproduction system.
Pacemaker: Collection of cells that stimulates the pumping action of the heart.
Paleontology: The study of fossils or extinct organisms.
Parasitism: Ecological relationship in which one organism benefits by harming another organism.
Parasympathetic Nervous System: Part of the autonomic nervous system that calms the body and helps the body to conserve energy.
Parenchyma Cell: Cell with thin walls that form tissues within leaves, roots, stems, and fruit of plants.
Particulate: Microscopic bits of dust, metal, and unburned fuel produced by industrial processes.
Passive Immunity: Immunity that occurs without the body undergoing an immune response.
Passive Transport: Movement of molecules across the cell membrane without energy input from the cell.
Pathogen: Agent that causes disease.
Pathogen: An agent that causes disease
Pedigree: Chart of the phenotypes and genotypes in a family that is used to determine whether an individual is a carrier of a recessive allele.
Peripheral Nervous System: Division of the nervous system that transmits impulses between the CNS and other organs in the body.
Petal: modified leaf structure that surrounds a flower’s reproductive structures.
Petiole: stalk that attaches a leaf blade to a stem.
PH: Measurement of acidity; related to free hydrogen ion concentration in a solution.
Phagocyte: Cell that destroys other cells by surrounding and engulfing them.
Phagocytosis: Uptake of a solid particle into a cell by engulfing the particle (see endocytosis).
Pharmacology: The study of drugs and their effects on the body.
Phenotype: Collection of all of an organism’s physical characteristics.
Phloem: tissue that transports sugars in vascular plants.
Phospholipids: A molecule that forms a double-layered cell membrane; contains glycerol, a phosphate group, and two fatty acids.
Photosynthesis: Process by which light energy is converted to chemical energy; produces sugar and oxygen from carbon dioxide and water.
Photosystem: Series of light-absorbing pigments and proteins that capture and transfer in the thylakoid membrane.
Phylogeny: the evolutionary history or a group of related species.
Phylum: Group of animals defined by structural and functional characteristics that are different from every other phylum.
Phytoplankton: Photosynthetic microscopic protists, such as algae.
Pioneer Species: Organism that is the first to live in a previously uninhabited area.
Placenta: Organ that develops in female mammals during pregnancy and carries nutrients from the mother to the embryo.
Plankton: Microscopic, free-floating organisms, which may be animals or protists, which live in the water.
Plant: Multicellular eukaryote that produces its own food through photosynthesis.
Plasmid: Circular piece of genetic material found in bacteria that can replicate separately from the DNA of the main chromosome.
Plasmid: Circular piece of genetic material found in bacteria that can replicate separately from the DNA of the main chromosome.
Point Mutation: Mutation that involves a substitution of only one nucleotide.
Polar Body: Haploid cell produced during meiosis in the female of many species; these cells have little more than DNA and eventually
disintegrate.
Pollen Grain: Two-celled structure that contains the male form of the plant’s gamete.
Pollination: Process by which seed plants become fertilized without the need for free-standing water.
Pollution: Anything that is added to the environment and has a negative affect on the environment or its organisms.
Polygenic Trait: Trait that is produced by two or more genes.
Polymer: Large, carbon-based molecule formed by monomers.
Population Crash: Dramatic decline in the size of a population over a short period of time.
Population Density: Measure of individuals living in a defined area.
Population Dispersion: Way in which individuals of a population are spread out over an area or volume.
Population: All of the individuals of a species that live in the same area.
Predation: Process by which one organism hunts and kills another organism for food.
Pressure-flow model: model for predicting how sugars are transported from photosynthetic tissue to the rest of a plant.
Primary Growth: growth in vascular plants resulting in elongation of the plant body.
Primary Succession: Establishment and development of an ecosystem in an area that was previously uninhabited.
Primate: Mammal with flexible hands and geed, forward-looking eyes, and enlarged brains relative to body size.
Probability: Likelihood that a particular event will happen.
Producer: Organism that obtains its energy from abiotic sources, such as sunlight or inorganic chemicals.
Product: Substance formed by a chemical reaction.
Prokaryotic cell: A cell without a nucleus and other membrane-bound organelles.
Promisians: Oldest primate group that includes mostly small, nocturnal primates such as lemurs.
Promoter: Section of DNA to which RNA polymerase binds, starting the transcription of mRNA.
67
432. Prophase: First phase of mitosis when chromatin condenses, the nuclear envelope breaks down, the nucleolus disappears, and the
centrosomes and centrioles move to opposite sides of the cell.
433. Protein: Polymer composed of amino acids linked by peptide bonds; folds into a particular structure depending on bonds between amino
acids.
434. Proteomics: Study and comparison of all the proteins produced by an organism’s genome.
435. Protist: A eukaryote that is not an animal, plant, or fungus.
436. Protozoa: Animal-like protist.
437. Pseudopod: Temporary extension of the cytoplasm and plasma membrane that helps protozoa move and feed.
438. Puberty: Stage of adolescence that is marked by the production of hormones involved in reproduction.
439. Pulmonary Circulation: Circulation that occurs between the lungs and the heart.
440. Punctuated Equilibrium: theory that states that speciation occurs suddenly and rapidly followed by long periods of little evolutionary change.
441. Punnet Square: Model for predicting all possible genotypes resulting from a cross.
442. Purebred: Type of organism whose ancestors are generally uniform.
443. Radial Symmetry: Arrangement of body parts in a circle around a central axis.
444. Radiometric Dating: Technique that measures the natural decay rate of isotopes to calculate the age of material.
445. Reactant: Substance that is changed by a chemical reaction.
446. Receptor: Protein that detects a signal molecule and performs an action in response.
447. Recessive: Allele that is not expressed unless two copies are present in an organism’s genotype.
448. Recombinant DNA: Genetically engineered DNA that contains genes from more than one organism or species.
449. Reflex Arc: Nerve pathway in which an impulse crosses only two synapses before producing a response.
450. Regeneration: Process by which a new plant can grow from a fragment of a nonreproductive structure, such as a root, stem, or leaf.
451. Relative Dating: Estimate of the age of a fossil based on the location of fossils in strata.
452. Renewable Resource: Resource that replenishes itself quickly enough so that it will not be used faster than it can be produced.
453. Replication: Process by which DNA is copied.
454. Reproductive Isolation: Final stage in speciation, in which members of isolated population are either no longer able to mate or no longer to
produce viable offspring.
455. Reproductive System: Body system that allows for reproduction, including testes, ovaries, uterus, and other male and female organs.
456. Restriction Enzyme: Enzyme that cuts DNA molecules at specific nucleotide sequences.
457. Restriction Map: Diagram that shows the lengths and fragments between restriction sites in the strand of DNA.
458. Retrovirus: Virus that contains RNA and uses the enzyme reverse transcriptase to make a DNA copy.
459. Ribosomal RNA: RNA that is in the ribosome and guides the translation of mRNA into a protein; also used as a molecular clock.
460. Ribosome: Organelle that links amino acids together to form proteins.
461. Ribozyme: RNA molecule that can catalyze specific chemical reactions.
462. RNA Polymerase: Enzyme that catalyzes the synthesis of a complementary strand of RNA from a DNA template.
463. RNA: Nucleic acid molecule that allows for the transmission of genetic information and protein synthesis.
464. Root Cap: mass of cells that covers and protects the tips of plant roots.
465. Root Hair: thin hair like outgrowth of an epidermal cell of a plant root that absorbs water and minerals from the soil.
466. Sclerenchyma Cell: thick-walled, lignin rich cells that form a supportive plant tissue.
467. Scrotum: Skin that encloses the testes outside of the male body.
468. Secondary Growth: growth in woody plants resulting in wider roots, branches, and stems.
469. Secondary Succession: Reestablishment of a damaged ecosystem in an area where the soil was left intact.
470. Seed: Structure used by some land plants to store and protect the embryo.
471. Selective Permeability: Condition or quality of some, but not all, materials to cross a barrier or membrane.
472. Semen: White substances that contains sperm and fluids produced by sex glands of the male reproductive system.
473. Sepal: modified leaf that covers and protects the flower while it develops.
474. Sex Chromosome: Chromosome that directly controls the development of sexual characteristics.
475. Sex-Linked Gene: Gene that is located on a sex chromosome.
476. Sexual Reproduction: Process by which two gametes fuse and offspring that are a genetic mixture of both parents are produced.
477. Sexual Selection: Selection in which certain traits enhance mating success; traits are, therefore, passed on to offspring.
478. Sexually Transmitted Disease: A disease that is passed from person to person during sexual contact.
479. Smog: Air pollution in which gases released from burning fossil fuels form a fog when they react with sunlight.
480. Solute: Substance that dissolves in a substance and is present at a lower concentration than the solvent.
481. Solution: Mixture that is consistent throughout; also called a homogeneous mixture.
482. Solvent: Substance in which solutes dissolve and that is present in the greatest concentration in a solution.
483. Somatic Cells: Cells that make up all body tissues and organs, except gametes.
484. Somatic Nervous System: Division of the peripheral nervous system that transports signals from the brain to the muscles that produce
voluntary movements.
485. Specialist: Consumer that eats only one type of organism.
68
486.
487.
488.
489.
490.
491.
492.
493.
494.
495.
496.
497.
498.
499.
500.
501.
502.
503.
504.
505.
506.
507.
508.
509.
510.
511.
512.
513.
514.
515.
516.
517.
518.
519.
520.
521.
522.
523.
524.
525.
526.
527.
528.
529.
530.
531.
532.
533.
534.
535.
536.
537.
Speciation: Evolution of two or more species from ancestral species.
Species: Group of organisms so similar to one another that they can breed and produce fertile offspring.
Species: Group of organisms so similar to one another that they can breed and produce offspring.
Sperm: Male gamete.
Sporophyte: diploid, spore-producing phase of a plant life cycle.
Stabilizing Selection: Pathway of natural selection in which intermediate phenotypes are selected over phenotypes at both extremes.
Stamen: male structure of flowering plants; includes the stalk and anther, which produces pollen.
Start Codon: Codon that signals to ribosomes to begin translation; codes for the first amino acid in a protein.
Stem Cell: Cell that can divide for long periods of time while remaining undifferentiated.
Stomata: Pores in the cuticle of a plant through which gas exchange occurs.
Stop Codon: Codon that signals ribosomes to stop translation.
Substrate: Reactant in a chemical reaction upon which an enzyme acts.
Succession: Sequence of biotic changes that regenerate a damaged community or start a community in a previously uninhabited area.
Survivorship Curve: Graph showing the surviving members of each age group of a population over time.
Sustainable Development: Practice of not using natural resources more quickly than they can be replenished.
Symbiosis: Ecological relationship between members of at least two different species that live in direct contact with one another.
Sympathetic Nervous System: Part of the autonomic system that prepares the body for action and stress.
System: Changing, organized group of related parts that interact to form a whole.
Systemic Circulation: Circulation that occurs between the body and the heart, excluding the lungs.
Systolic Pressure: Measure of pressure on the walls of an artery when the left ventricle contracts to pump blood through the body.
Taiga: Biome with long and cold winters, lasting up to six months; also called a boreal forest.
Taproot: main root of some plants, usually larger than other roots and growing straight down from a stem.
Taxon: a level within the Linnaean Classification system (Ex. Class, phylum, etc.) that is organized into a nested hierarchy.
Taxonomy: the science of naming and classifying organisms.
T-Cell: White blood cell that matures in the thymus and destroys infected body cells by causing them to burst; also called a T-lymphocyte.
Telomere: Repeating nucleotide at the ends of DNA molecules that do not form genes and help prevent loss of genes.
Telophase: Last phase of mitosis when a complete set of identical chromosomes is positioned at each pole of the cell, the nuclear membranes
start to form, the chromosomes begin to uncoil, and the spindle fibers break apart.
Temporal Isolation: Isolation between populations due to difference related to time, such as differences in mating periods or the time of day
that individuals are most active.
Test Cross: Cross between an organism with an unknown genotype and an organism with a recessive phenotype.
Testis: Organ of the male reproductive system that produces sperm.
Testosterone: Steroid hormone that is found in greater quantities in men than women and contributes to male sexual characteristics and
development.
Theory: Proposed explanation for a wide variety of observations and experimental results.
Thylakoid: Membrane bound structure within chloroplasts that contains chlorophyll and other light-absorbing pigments used in the lightdependent reactions of photosynthesis.
Tissue Rejection: Process by which a transplant recipient’s immune system makes antibodies against the protein markers on the donor’s tissue; can result in the destruction of the donor tissue.
Tissue: Group of cells that work together to perform a similar function.
Toxin: Poison released by an organism.
Trait: Inherited characteristic.
Transcription: Process of copying a nucleotide sequence of DNA to form a complementary strand of mRNA.
Transfer RNA: Form of RNA that brings amino acids to ribosomes during protein synthesis.
Transgenic: Organism whose genome has been altered to contain one or more genes from another organism or species.
Transgenic: Organism whose genome has been altered to contain one or more genes from another organism or species.
Translation: Process by which mRNA is decoded and a protein is produced.
Transpiration: release of vapor through the pores of the skin or the stomata of plant tissue.
Trimester: One of three periods of approximately three months each which a human pregnancy is divided.
Trophic Level: Level of nourishment in a food chain.
Tundra: Biome found at far northern latitudes where winters last as long as ten months per year.
Umbilical Cord: Structure that connects an embryo to its mother and provides the embryo with nourishment and waste removal.
Umbrella Species: Species that being protected under the Endangered Species Act leads to the preservation of its habitat and all of the other
organisms in its community.
Uniformitarianism: Theory that states that the geologic processes that shape Earth are uniform through time.
Uterus: Organ of the female reproductive system in which a fertilized egg attaches and a fetus develops.
Vaccine: Substance that stimulates an immune response, producing acquired immunity without illness or infection.
Vaccine: Substance that stimulates an immune response, producing acquired immunity without illness or infection.
69
538.
539.
540.
541.
542.
543.
544.
545.
546.
547.
548.
549.
550.
551.
552.
553.
554.
555.
556.
557.
558.
Vacuole: An organelle used to store materials, such as water, food, or enzymes that are needed by the cell.
Valve: Flap of tissue that prevents blood from flowing backward into a blood vessel or heart chamber.
Variation: Differences in physical traits of an individual from the group to which it belongs.
Vas Deferens: Duct in which sperm mixes with other fluids before reaching the urethra.
Vascular Cylinder: center of a root or stem that contains phloem and xylem.
Vascular System: Collection of specialized tissues in some plants that transports mineral nutrients up from the roots and brings sugars down
from the leaves.
Vascular Tissue: supportive and conductive tissue in plants, consisting of xylem and phloem.
Vector: Organism, such as a mosquito or tick, that transfers a pathogen from one host to another
Vegetative Reproduction: Actual reproduction in which a stem, leaf, or root will produce a new individual when detached from a parent plant.
Vein: Large blood vessel that carries blood from the rest of the body to the heart.
Ventricle: Large chamber in the heart that receives blood from an atrium and pumps blood to the rest of the body.
Vertebrate: An animal with an internal segmented backbone.
Vesicle: Small organelle that contains and transports materials within the cytoplasm.
Vestigial Structure: Remnants of an organ or structure that functioned in an earlier ancestor.
Virus: Infectious particle made only of a strand of either DNA or RNA surrounded by a protein coat.
Watershed: Region of land that drains into river, river system, or other body of water.
Wood: Fibrous material made of dead cells that are part of the vascular system in some plants.
X Chromosome Inactivation: Process that occurs in female mammals in which one of the X chromosomes is randomly turned off in each cell.
Xylem: tissue that transports water and dissolved minerals in vascular plants.
Zooplankton: Animal plankton.
Zygote: Cell that forms when a male gamete fertilizes a female gamete.
70
Answering Test Questions
When answering questions, remember that
The test is a multiple choice format.
One of the answers given has to be the right answer.
You can use the supplemental tools if necessary
o Straightedge
o Eliminate Answer Choice
o Highlighter
o Calculator
o Periodic Table
o Etc.
They will usually have some kind of scenario where you have to apply your knowledge.
Just knowing the facts may not be enough. You should understand the reasoning and
logic behind concepts or facts.
There are four difficulty levels of thinking:
o Recalling a Fact, Formula, or Definition
o Basic Application of Concepts & Skills
o Strategic Thinking & Complex Reasoning
o Extended Thinking & Complex Reasoning
The EOC loves to give graphs, charts, or some other visuals. Referring to this, they could
ask questions such as (but not limited to):
o Why biological process or concept is illustrated by the visual?
o Make a prediction if…
o What can be concluded about the visual?
o Referring to the diagram, what is the name of the item labeled A?
o What is a pattern that is shown in the diagram?
o What is the step labeled “A” called?
If you really don’t know how to approach a question, then guess as a absolute last resort, after making every attempt to answer the question.
71
Works Cited
McClean, Phillip. "Mendelian Genetics." Mendelian Genetics. North Dakota State University,
2000. Web. 28 Apr. 2013.
Nowicki, Stephen, PH.D. Biology Grades 9-12 Holt Mcdougal Biology Florida. N.p.: Holt
McDougal, 2012. Print.
"Standards." Welcome to CPALMS. Florida Department of Education, n.d. Web. 28 Apr. 2013.
THIS BIOLOGY EOCSTUDY GUIDE WAS CREATED BY DOMINICK HING
72