a. Major Fields of Biology The living organisms are composed of cells which consist of very complex structure, even more complex than any of the recently man made machine. The body of unicellular organisms are composed of single cells then those of higher organisms, plant and animals both are composed of more cells. These cells are organized in to tissues that are grouped into organs and organs into systems. The living organisms are different from one another on the basis of function, size, shape, structure, reproduction, habitat and so many other aspects. Various disciplines have developed to study these aspects of living organisms. some of them are discuss below. Micro - Biology: In this branch of biology we study about those organisms which can not be seen by naked eye and can only be seen with help of microscope. e.g. bacteria, fungi, virus etc. Environmental Biology: It deals with the study of living organisms in relation to their environment. different habitats have different environment. It is also known as Ecology. Molecular Biology: It is that branch of biology which deals with the study of those molecules which are present in the cells of living organisms. Fresh Water Biology:

1. Part I
a. Major Fields of Biology
The living organisms are composed of cells which consist of very complex structure, even more complex than any of the
recently man made machine. The body of unicellular organisms are composed of single cells then those of higher
organisms, plantand animals both are composed of more cells. These cells are organized in to tissues that are grouped
into organs and organs into systems. The living organisms are different from one another on the basis of function, size,
shape, structure, reproduction, habitat and so many other aspects. Various disciplines have developed to study these
aspects of living organisms. some of them are discuss below.
Micro - Biology:
In this branch of biology we study aboutthose organisms which can not be seen by naked eye and can only be
seen with help ofmicroscope. e.g.bacteria, fungi, virus etc.
Environmental Biology:
It deals with the study of living organisms in relation to their environment. differenthabitats have different
environment. It is also known as Ecology.
Molecular Biology:
It is that branch of biology which deals with the study of those molecules which are presentin the cells ofliving
organisms.
Fresh Water Biology:
Water bodies are oftwo types. Fresh water and ocean water. All water bodies other than oceans are known as
fresh water e.g river, streams, canals, lakes, springs,ponds etc.
Marine Biology:
It deals with the study of those organisms that lives in oceans. The habitat ofthe ocean is called marine habitat
and the organisms inhibiting marine habitat are called marine organisms.
Parasitology:
Parasites are living organisms which gettheir food from the host. It is that branch of biology which deals with the
study of parasites.
Human Biology:
Human biology is related to the study ofthe all aspects ofhuman body e.g anatomy, physiology,pathology
biochemistry etc.
Social Biology:
This is the sub- branch ofbiology which deals with the study ofpopulations and communities ofplants and animals
and their interaction with each other.
Bio - Technology:
It is defined as the application oforganism, biological system for the benefitofhuman beings. Itprovide both
productand services.Example ofproducts is cheese and human insulin while that ofservice is the treatment ofsewage.
b. Importance of Biology
Biology is important because it allows people to understand the diversity of life forms and their
conservation and exploitation. Through various biological disciplines, people obtain knowledge about life
and living organisms, including the origin, growth, evolution, structure, distribution and function of these
organisms.

2. c. What is life?
What Is Life? is a 1944 non-fiction science book written for the lay reader by physicist Erwin Schrödinger. The book
was based on a course of public lectures delivered by Schrödinger in February 1943, under the auspices of
the Dublin Institute for Advanced Studies at Trinity College, Dublin. The lectures attracted an audience of about 400,
who were warned "that the subject-matter was a difficult one and that the lectures could not be termed popular,
even though the physicist’s most dreaded weapon, mathematical deduction, would hardly be
utilized."[1]
Schrödinger's lecture focused on one important question: "how can the events in space and time which
take place within the spatial boundary of a living organism be accounted for by physics and chemistry?"
d. The Scientific Methods
The scientific method is a body of techniques for investigating phenomena, acquiring newknowledge, or correcting
and integrating previous knowledge.[2]
To be termed scientific, a method of inquiry is commonly based
on empirical or measurable evidence subject to specific principles of reasoning.[3]
The Oxford English
Dictionary defines the scientific method as "a method or procedure that has characterized natural science since the
17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and
modification of hypotheses."
The scientific method is an ongoing process, which usually begins with observations about the natural world. Human
beings are naturally inquisitive, so they often come up with questions about things they see or hear and often
develop ideas (hypotheses) about why things are the way they are. The best hypotheses lead to predictions that can
be tested in various ways, including making further observations about nature. In general, the strongest tests of
hypotheses come from carefully controlled and replicated experiments that gather empirical data. Depending on
how well the tests match the predictions, the original hypothesis may require refinement, alteration, expansion or
even rejection. If a particular hypothesis becomes very well supported a general theory may be developed.
e. Branches of Biology
36 Different Branches of Biology and What They Mean
The following are the various branches of biology:
 Botany is the study of plants.
 Zoology is the study of animals.
 Anatomy is the study of the internal structures of
living things.
 Biochemistry is the use of chemistry in the study
of living things.
 Biological EarthScience is the use of earth
sciences, such as geography in the study of
living things.
 Biological Psychology is the use of biology in
psychological studies.
 Biomathematics is the use of mathematics in the
study of living things.
 Biophysics is the use of physics in the study of
living things.
 Ecology is the study of the relationships of living
things to each other and their environment.
 Pathology is the study of diseases, generally in
animals.
 Phytopathology is the study of diseases in
plants.
 Physiology is the study of normal functions of
living things.
 Taxonomy is the classification and naming of
living things.
 Genetics is the science of heredity and the
lifelong development of living things.
 Embryology is the study of the formation and
development of living things from fertilization to
birth as independent organisms.
 Pharmacology is the study of the actions of
chemicals on and in living things.
 Endocrinology is the study of hormones and their
actions.
 Cytology is the study of cells.
 Histology is the study of tissues.
 Protozoology is the study of one-
celledorganisms.
 Bacteriology is the study of bacteria.
 Virology is the study of viruses.
 Mammalogy is the study of mammals.
 Ornithology is the study of birds.
 Herpetology is the study of reptiles and
amphibians.
 Ichthyology is the study of fishes.
 Entomology is the study of insects.
 Helminthology is the study of worms.
 Microbiology is the study of microorganisms.
 Mycology is the study of fungi.
 Phycology is the study of algae.
 Lichenology is the study of lichens.
 Paleontology is the study of fossils.
 Biogeography is the study of geographical
distribution of living things.
 Phytogeography is the study of the land and its
plants.
 Zoogeography is the study of the land and its
animals.

3. Part II
a. The Chemistry of the Cell
The living cell is a symphony ofthousands of chemical reactions all miraculously timed and coordinated to perform
all the functions necessary for life.
Amazingly, this symphony has only a few major players; only six elements carbon, hydrogen, oxygen, nitrogen,
phosphorus, and sulfur(sometimes called CHNOPS;>) make up about98% of the mass of all living organisms.
Carbon is a unique elementwith the remarkable ability to form strong, stable chemical bonds with other atoms
(keeps you from falling apart.) Each carbon atom can form four bonds with other atoms. (Sometimes, two atoms
will form more than one bond between themselves making a double bond or even a triple bond.)
This bonding ability allows carbon atoms to form chains of almostunlimited length. These chains can be closed on
themselves to form rings or may branch wildly. This gives greatvariety to the kinds ofmolecules thatcarbon can
form. Below are just a few examples ofthe many ways carbon chains can be arranged to form the skeleton for
different molecules.
b.
c. Atoms ofhydrogen and oxygen and less frequently nitrogen, sulfur, or phosphorous are bonded to the carbon
skeleton to form giant molecules called macromolecules. A few other elements may occur in trace amounts.
The four major types ofmacromolecules found in living cells—carbohydrates, lipids,proteins,and nucleic acids--
are made ofsmaller, repeating subunits called monomers. The monomers are notalways identical butthey always
have similar chemical structures. They are joined together by a series ofchemical reactions in a process called
polymerization to form large, complex molecules called polymers.
The Four Major Types of Macromolecules Found in Living Cells
Macromolecule Elements Monomer Polymer example
Carbohydrate C, H, O Simple sugars Polysaccharide Starch
Lipids C, H, O Fatty acids & glycerol Lipid Fats, oils, waxes
Proteins C, H, O, N, S Amino acids Polypeptides Insulin
Nucleic acids C, H, O, P Nucleotides Nucleic acids DNA
d. The chemical diversity that polymerization allows living things is similar to the diversity that our alphabetallows our
language. Although there are only 26 letters in our English alphabet, our ability to join them together to form
words gives us an almostinfinite variety of possible words. Similarly, the monomer units ofmacromolecules can
be arranged with an almostendless potential for variety.
The functions of macromolecules are directly related to their shapes and to the chemical properties oftheir
monomers. The way the monomers are arranged in the macromolecule determines its shape and its function in
the same way that the arrangement of the letters in a word determine its sound and meaning.
Much ofa cell's activities involve the arranging and rearranging and bonding ofmacromolecules. Itis the job of
DNA both directly and indirectly to coordinate and directthese activities.
An understanding ofthe structure and functions ofcarbohydrates and lipids is notparticularly key to the
understanding ofmolecular genealogy.However, itmay be helpful to take a quick look atthe structure and
function ofproteins before moving on to the nitty gritty of the nucleic acids (ofwhich DNA is one.)

4. b.