Science and cells

What is Science
Science
Branches of Science
ƒ The study of the world around us
Branches of Natural
Science
Natural Science
ƒ Earth Science
ƒ Life Science
ƒ Physical Science
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The Scientific Method
The Problem: How do you get a cookie?
ƒ A systematic approach to answer a
question or problem
The Steps of the Scientific Method
1.Determine the question or problem–
ƒ the purpose of an investigation
2.Create a hypothesis
ƒ Predicted outcome of the question
3.Design and conduct an experiment (Test)
ƒ The steps you take to answer your question
4.Collect and analyze data (observations)
ƒ Data—what you measure
ƒ Analyze—determine what the data means
5.State a conclusion
ƒ Was your hypotheses correct based on your data
6.Repeat work to confirm conclusion
2
The Scientific Method
Test the Hypothesis
• Under Control A controlled experiment tests only
one factor at a time and consists of a control group
and one or more experimental groups.
Variables
Variable is anything that can affect the
outcome of an experiment
ƒ Control Variable Æ remains the same
ƒ Experimental Variable Æ changes during the
experiment
The Building Blocks
of Life
3
The characteristics of living things
All living things:
1.
2.
3.
4.
5.
6.
Heterotroph or autotroph
ARE MADE OF CELLS
RESPOND TO THEIR ENVIRONMENT
REPRODUCE
OBTAIN AND USE ENERGY
GROW AND DEVELOP
DNA—ability to pass on traits
Life has to come from living things
Autotrophs--organisms who can produce their own
food (plants)
Heterotrophs– organisms that obtain their food
from autotrophs (animals)
The Microscope
/Light
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Chapter 3
Section 3 The Organization of
Living Things
Cell Theory
Organisms
1. All living things are made of
cells
2. Cells are the basic unit in
living things
3. All cells come from other cells
• Anything that can perform life processes by itself is
an organism.
• An organism made of a single cell is a unicellular
organism. A unicellular organism must carry out all
life processes in order for that cell to survive.
• In contrast, multicellular organisms have
specialized cells that depend on each other for the
organism to survive.
Spontaneous generation=life coming from non-living things
Cell Structure
ƒ Prokaryotes—organisms who lack
nuclei (Bacteria)
ƒ No membrane bound organelles
ƒ Small unicellular organisms
ƒ Eukaryotes—organisms who have
a nuclei
ƒ Have membrane bound organellesmitochondria, chloroplast
ƒ Can be multicellular
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Prokaryote or Eukaryote
Vocabulary: Parts of a cell
OrganelleCell membrane-
Prokaryote or Eukaryote?
Parts of a cell
Organelle- small structure in a cell that performs a specific function
Similar to organs in our Body
Cell membrane-layer surrounding the cell
Controls what moves in and out of the cell
CytoplasmCytoplasm-fills the space inside the cell
NucleusNucleus- Large dark structure in the cell --Control center
Chromatin—
Chromatin—genetic material or DNA (Code for life)
Mitochondria—
Mitochondria—Power house of the cell
Vacuoles—
Cell wall-
Vacuoles—store water and waste
These are very large in plant cells
Chloroplast-
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What are the differences between plants and animal cells?
Chloroplasts—converts sunlight into chemical energy—plant cells only
Cell Wall- in plants and some bacteria (not animals)
Protects the cell and gives it strength and rigidity
Vacuole—Much larger in plants
Label the following organelles and their functions
Label the following organelles and their functions
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How Big are They
ƒ?
8
Onion
Elodea
9
Cheek
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Chapter 3
Section 3 The Organization of
Living Things
Objectives
• List three advantages of being multicellular.
• Describe four levels of organization in living things.
• Explain the relationship between the structure and
function of a part of an organism.
Chapter 3
Section 3 The Organization
of Living Things
Chapter 3
Section 3 The Organization of
Living Things
The Benefits of Being Multicellular
Cells Working Together
• Larger Size Larger organisms are prey for fewer
predators. Larger predators can eat a wider variety of
prey.
• A tissue is a group of cells that work together to
perform a specific job.
• Longer Life The life span of a multicellular organism
is not limited to the life span of a single cell.
• Specialization Each type of cell has a particular job.
Specialization makes the organism more efficient.
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Chapter 3
Section 3 The Organization of
Living Things
Chapter 3
Section 3 The Organization of
Living Things
Tissues Working Together
Tissues Working Together, continued
• organ-- A structure made up of two or more tissues
working together to perform a specific function
•organ system-- A group of organs working together
to perform a particular function
•heart, stomach, intestines, brain, and lungs are.
•digestive system, the respiratory system, and the
cardiovascular system.
• Leaves, stems, and roots
Chapter 3
Section 3 The Organization of
Living Things
Chapter 3
Section 3 The Organization of
Living Things
Overview of Organ Systems
Click below to watch the Visual Concept.
Visual Concept
You may stop the video at any time by pressing
the Esc key.
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Chapter 3
Section 3 The Organization of
Living Things
Chapter 3
Section 3 The Organization of
Living Things
Structure and Function, continued
Structure and Function
• In organisms, structure and function are related.
• Structure is the arrangement of parts in an
organism.
• Function is the job that the part does.
Chapter 3
Cells: The Basic Units of Life
• The structures of alveoli
and blood vessels enable
them to perform a
function. Together, they
bring oxygen into the body
and get rid of its carbon
dioxide.
Chapter 3
Cells: The Basic Units of Life
Concept Map
Use the terms below to complete the concept map
on the next slide.
prokaryotes
cells
do
do not
plants
eubacteria
humans
bacteria
eukaryotes
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