The Science of Life
Chapter 1
Biology is the study of living things
Bio = living; logos = knowledge
Introduction
• Biology is the study of living things. 2nd Name?
• Unity in Diversity – Living things = organisms
display great variety in form and function, but
inside all have similar basic qualities
• We divide them into 3 largest groupings –
Domains – Bacteria, Archaea, and Eukarya
• Domain Eukarya has 4, 2nd largest groupings –
Kingdoms – Protists, Plants, Fungi, and
Animals
Fig. 1.16
5 Characteristics of Living-things
• Cellular Organization – all living things = organisms are
formed of 1 or more cells
• Metabolism – is the sum of all simple and complex
chemical reactions occurring in organisms.
• Homeostasis – organisms maintain internal conditions
within limits; disease is a failure to maintain
homeostasis
• Growth and Reproduction – living things grow by
transforming food into cells or cellular parts
• Heredity – is the transfer of characters from parents to
offspring (next generation)
Fig. 1.11
Cells
• Cells –Each cell is a microscopic unit covered
by cell membrane and has DNA that has the
all the information needed for growth and
reproduction of cell.
• Prokaryotic cells are simple with no internal
membranes. For example in bacteria
• Eukaryotic Cells have DNA inside nucleus.
Cytoplasm is present between cell membrane
and nucleus; cytoplasm has membrane bound
organelles. For example plants, animals, fungi
Fig. 5.9
Fig. 5.10
Recap 1 Lecture 1
1.------------- is the study of living things; bio = ---------------------.
2.--------- -- ------------- means that living things look different from one another but
share same basic characteristics.
3.Living things are divided into 3 largest groupings, ---------------------.
4.3 domains of living things are ------------, -------------, and --------------.
5.Domain Eukarya is divided into 4 ------------------.
6.------------ and ----------- are domains of Eukarya.
7.All living things are made of 1 or more ---------------.
8.-----------is the sum of simple and complex chemical reactions occurring in organisms.
9.---------- is maintenance of internal conditions within limits despite of changing
environment outside.
10.----------- is the transference of characters from 1 generation to next generation.
11.The information about color of hair and eyes passes through ------------ which are
formed of DNA.
12.--------- cells occur in bacteria and are simple cells having DNA in liquid cytoplasm
covered by cell membrane. No internal membranes are present in these cells.
13.--------- cells have DNA covered by nucleus and also have membrane covered
organelles like mitochondria, ER, and Golgi apparatus.
Organization of Life
• Atoms: All things are formed of tiny compartments atoms. H, C, O
are atoms that unite to form molecules.
• Molecules: are stable grouping of atoms of same or different kinds.
H2O, glucose C6H12O6. Molecules join to form cells.
• Cells are the unit of structure and function. Cells join to form
tissues.
• Tissues are groups of similar cells specialized for 1 function.
Muscles, bones, and blood are tissues. Tissues join to form organs.
• Organs are specialized for 1 main function, heart for pumping
blood, lungs for respiration. Organs join to form organ-systems.
• Organ-systems are connected organs having related functions.
Digestive system, Nervous system. All organ-systems join to form
body or organism.
• Organism is individual living thing. Human, monkey, apple tree.
Fig. 1.4a
Organization of Life - 2
• Population is group of similar individuals living at one place at
same time. Population is a breeding unit. All populations of
similar organisms living at different places form a Species.
Humans, male and female, young and old, living at 1 place form
a population. Humans of world form a species.
• Community is all populations of different kinds living at 1 place.
• Ecosystem is the interaction of community (biotic component)
with non-living surroundings (abiotic component) at a place.
Desert, Rain forest, lake, are some examples of ecosystem.
• Biosphere is the largest ecosystem with land, water,
atmosphere and all living things of world.
Fig. 1.4b
Biological Themes
• Important themes repeatedly used in Biology are
• Evolution, Homeostasis, DNA and Flow of Energy.
• Evolution means all species of living things developed from 1
simple single celled ancestor due to changes in DNA and
adaptations to changing environment. Fig 2.5
• Evidence for evolution is in the form of fossils, mineralized
remains of organisms living long time back. Fig 2.4
Fig. 2.5
Fig. 2.4
Flow of Energy
• Flow of Energy: nutrients constantly cycle between biotic and
abiotic components of an ecosystem; but energy must
constantly flow from sunlight into ecosystem because it is
regularly lost as unusable heat from the ecosystem. Fig 2.14
Fig. 2.14
Scientific Method
• Scientific Method: Science develops by 1) discovering new
things, processes, and phenomena 2) asking right question;
developing explanations and testing them repeatedly until all
wrong ones are eliminated. Main steps include:
• Observation, Question, Hypothesis, Predictions, Experiment,
Control – similar to experiment but lacks variables; helps to
eliminate other hypotheses, Conclusions and Theory.
• Conclusions result from supported or rejected hypotheses.
Deductive Reasoning
Inductive Reasoning
Based on facts/principle
Possible explanation to find
general principle
Observation  generalization
Generalization  prediction
Used in Maths/Computation
Used in science
Fig. 1.8
Fig. 1.7
Fig. 1.6
Recap 2 Lecture 1
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------------ is the smallest compartment to retain the properties of any substance.
Water and carbon dioxide are examples of -----------------.
--------- and ------------- are 2 examples of tissues.
Tissues join to form next level called -----------.
----------- is a group of individuals of 1 kind living at same place at same time.
---------- is the interactive grouping of all populations at 1 place.
Biotic components (------------) and abiotic components (like --------- and -----) form
an ecosystem.
------------ means all species of living things developed from 1 simple single celled
ancestor due to changes in DNA and adaptations to changing environment.
--------- are mineralized remains of organisms living long time back.
---------- is the ultimate source of energy of almost all organisms.
Energy --------- but ------------cycle through an ecosystem.
--------- reasoning is based on fact and observation leads to generalization.
In scientific method ---------- leads to a question and ----------- possible explanation
to find general principle.
Ozone hole is observed over Antartica and is formed due to release of Chlorine
from ------- used in refrigeration and other industry.
Chapter 3 – Basic Chemistry
• Matter: All things are made of Matter. Matter
exists in 3 states: Solid, Liquid and Gas.
• Matter is formed of 92 basic kinds called
elements. An element has atoms of only 1
kind.
• Element Hydrogen has the smallest atoms and
element Uranium has the largest atoms.
Fig. 3.1
Atom
• Atom: The smallest part of a substance to retain its
properties. The smallest is Hydrogen and the largest is
Uranium.
• Nucleus: An atom is formed of a very small central
dense part called Nucleus having protons and neutrons.
• Proton: It has + particles called a Protons. It determines
Element.
• Neutron: Atoms have in their nucleus a neutral particle
called a Neutron. It determines Isotope.
• Electron: Around the nucleus is a large hollow area in
which really small – particles called Electrons move
very fast around the nucleus. Electrons in the
outermost shell determine chemical properties.
6/19/2007
Fig. 3.5
Table 3.2
Chemical Bonds
• Covalent Bond is formed by sharing an electron pair
between 2 atoms. These are strongest bonds.
• Equal shared covalent bonds like H – H, O = C =O have
no charge on atoms. H2, O2, CO2
• Unequal shared covalent bonds like H – O – H have
partial charges over atoms. This produces weak bonds
called H-bonds, for example H2O molecules.
• Ionic bond is present between 2 ions formed due to
complete transfer of electron/s. this produces higher
unit charges and strong bonds.
Fig. 3.9
Fig. 3.10
Fig. 3.8
Acids, Bases, Salts, Buffers
• Acids are chemicals that produce H+ , like HCl
• Bases accept H+ and may produce OH- ions, like NaOH
• Salts: Acids and bases react to form salts; salts produce
ions other than H+ or OH-. Like NaCl, table salt
• pH scale is used to measure the concentration of H+ in
any solution. It is a - log scale. It means the stronger the
acid the lower its pH.
• pH scale varies from 0 – 14.
• pH 7 is neutral; represented by pure water.
• Acidity increases from 7  0 by 10 for each digit
• Alkalinity increases from 7  14 by 10 for each digit.
• Buffers are chemicals that minimizes changes in pH.
Fig. 3.14
Recap 3 Lecture 1
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Chapter 3
------------exists in 3 states solid, liquid and gas.
Matter is formed of 92 -----------, Hydrogen to Uranium.
--------are positive charged particles in nucleus and determine ------------.
--------are negative charged particles orbiting around nucleus and determine --------.
--------are neutral particles present in nucleus and determine --------------.
------- -------means water molecules are attracted to ions and polar molecules.
2 atoms with same # of protons but different # of neutrons are different ------------.
---------bonds are formed between different water molecules due to their polar
nature. (weak bonds)
--------bonds are formed due to complete transfer of electron/s from 1 atom to
another. (strong )
--------bonds are formed due to shared electron pair between 2 atoms. (very
strong bonds)
------- produce H+; ----------accept H+ .
------- are formed due to reaction between acid and base.
pH of pure water is --------, strong acid is ------- and strong base is -----------.
----------resist fast changes in pH.