Chapter – 1
Introduction
DEFINITION OF BIOLOGY
Biology is the study of living organisms. It is derived from Greek
words.
CLASSIFICATION OF LIVING ORGANIZATION
According to the
modern classification given by R.H.Whittaker in 1969, living organisms are
divided into five major kingdoms, which are:
KINGDOM MONERA
It includes all
prokaryotes, unicellular organisms. For example Bacteria and Cyan bacteria.
KINGDOM PROTOCTISTA(PROTISTA)
It includes
unicellular Eukaryotic organisms, which are in between plants and animals. e.g.
Chlamydomonas, Euglena, Paramecium. etc
1. KINGDOM FUNGI
It includes non-chlorophyllus multi-cellular, thallophytic
organisms having cell wall. For example all types of fungi, unicellular to
multi-cellular like Mushrooms and Yeast etc.
2. KINGDOM PLANTAE
It includes all chlorophyllus multi-cellular Eukaryotic
living organisms having cellulose cell wall. For example apple, red wood etc.
3. KINGDOM ANIMALIA
It includes all Eukaryotic multi-cellular, non-chlorophyllus organisms having
no cell wall. For example Hydra, Earthworm, Human Beings etc.
EUKARYOTIC ORGANISMS
Those organisms,
which have true membranous structure in their cells, like mitochondria, golgi
bodies, endoplasmic reticulum. e.g. All plants, Higher animals.
PROKARYOTES
Those living
organisms, which do not have true membranous structure in their cells. e.g.
Bacteria, Blue green algae.
PHYLETIC LINEAGE
All living
organisms of today belong to a common ancestor and each specie of organism
arranged no ancestor to descendent order with rest of the group evolved from
one that immediately preceded.
BRANCHES OF BIOLOGY
1. MOLECULAR BIOLOGY
It is a recent branch of biological science that deals with the structure and
function of the molecules that form structure of cell and organelles that take
part in the biological processes of a living organism (Nucleic acid – Protein
molecule)
2. MICRO BIOLOGY
It deals with the study of micro-organisms (viruses, bacteria, protozoan etc)
3. ENVIRONMENTAL BIOLOGY
It deals with the study of environment and its effect on organisms.
4. MARINE BIOLOGY
It deals with the study of organisms inhabiting the sea an
ocean, and the physical and chemical characteristics of their environment.
5. FRESH WATER BIOLOGY
It deals with the life dwelling in fresh waters, physical
and chemical characteristics of fresh water bodies affecting it.
6. PARASITOLOGY
It deals with the study of parasitic organisms, their life
cycles, mode of transmission and interaction with their hosts.
7. HUMAN BIOLOGY
The branch of biology deals with all biological aspects of
man regarding evolution, anatomy physiology, health, inheritance etc.
8. SOCIAL BIOLOGY
Social biology is concerned with the social interactions
with in a population of a given species, especially in human beings focuses on
such issue as whether certain behavior are inherited or culturally induced.
9. BIOTECHNOLOGY
This is a very recent branch introduce in biological
sciences. It deals with the use of data and techniques of engineering and
technology for the study
and solution of
problems concerning living organisms particularly the human beings.
BIOLOGICAL METHOD
In order to solve
the biological problems (any animal or plant disease or environmental hazard),
following steps are necessary.
1. HYPOTHESIS
An educated guess
or fact regarding the biological problem.
INDUCTIVE REASONING
Isolated facts to reach a general idea that explain the
biological problem.
DEDUCTIVE REASONING
Accurate experimentation, true conclusions or results
regarding the biological problems.
2. OBSERVATION/EXPERIMENTS
The given
hypothesis is checked with the help of observation and experiments and then on
the basis of it a theory or rule is established.
3. THEORY
If observations and
experiments come true then hypothesis is taken true, other wise it is rejected.
Only on the basis of true hypothesis a theory is established.
4. LAW/PRINCIPLE
When theory is
proved to be true under all tested circumstances then it is accepted as a law.
MALARIA
§ Malaria means disease cause by bad air.
§ Actual Causative agent is plasmodium (Vector Female, Anopheles
Mosquito)
§ Leveran first discover plasmodium in human R.B.C.
§ Ronald Ross discovered plasmodium in the stomach of female
Anopheles Mosquito.
§ Grassi discover the complete life cycle of Plasmodium in human
being and mosquito.
ANTIBIOTICS
Substances or
chemicals, which are required in small quantity to inhibit the growth of
Microorganisms. The first antibiotic was penicillin discovered by Fleming.
Other examples are: Erythocin, Rythocin, Gentamycin, Ampicillin etc.
CHEMOTHERAPY
Treatment with drug
or chemical.
RADIOTHERAPY
Treatment with
radiations, like α, β, γ or X-rays.
HYDROPONICS
It is the science
of terrestrial plants growing in aerated solutions (add CO2 under pressure, in
any liquid also known as aerated water). This technique is also known as soil
less or water culture.
ADVANTAGES
1. Control weeds
and soil disease problems.
2. Area required for cultivation is minimum.
3. Can be applied on any part of the world.
4. Main purpose is to fulfill the food requirements of rapidly increasing world
population.
CLONING
Production of
duplicate copies of genetic material, cells or entire multicellular living
organisms, occurring naturally in plants or animals. Duplicate copies are known
as clones.
NATURAL CLONING
§ Identical twin, triplet in humans.
§ Asexual reproduction in plants and animal.
§ Regeneration and wound healing.
§ Growth of tumor cells or cancers.
ARTIFICIAL CLONING
§ Cloning of human cells such as liver cells, skin cells, blood
cells are quite helpful to develop human organs in laboratories.
§ There are also enormous advantages of cloning in the field of
medicine and agriculture. Examples are vegetative reproduction of fruits and
nuts by grafting.
§ Artificial cloning is also used for treating disease, production
of medically significant substances such as Insulin, growth hormones,
interferon and anti-thrombin etc.
LEVEL OF BIOLOGICAL ORGANIZATION
Life is built on
chemical foundation and the life of all living organisms emerges on the level
of cell. The foundation of cell is based on elements. Atoms of different
elements unite to form molecules. Living organism usually form extremely large
and complex molecules by living matter which is present in their bodies. The
molecules of living organisms are mostly composed of carbon and provide
building blocks of living matter. Mostly living matter of an organism is
composed of organic molecules along with inorganic compounds (minerals) are
also associated for e.g. Human blood. Simple organic molecules present in
living organisms are sugar, glycerol and fatty acids, amino acids, purine and
pyramidines. Similar types of cells form-tissues, similar tissues form organs,
different organs coordinating with each other form system and different systems
combine to form a living organism.
Cell → Tissues → organs → System → An Individual
Biological organization can be divided into the following levels:
SUB-ATOMIC PARTICLES
“Particles that make up an atom
are called sub-atomic particles”.
For e.g. electron, proton and Neutron.
ATOM
“The smallest particle of an
element that retains the property of that element”.
For example: Hydrogen, carbon and oxygen etc.
MOLECULE
“The combination of similar and
different atoms are called molecules”.
For example Hydrogen and oxygen combines to form water molecules.
ORGANELLE
“A structure with in a cell that
performs a specific function”.
For example: Mitochondria, chloroplast etc.
CELL
“The smallest structural and
functional unit of life”.
For example: A nerve cell
TISSUE
“A group of similar cells that
performs a specific function”.
For example: Nervous tissue.
ORGAN
“A structure with in an
organism usually compose of several tissue types that forms a functional unit”.
For example: The brain
ORGAN SYSTEM
“Two or more organs working
together in the execution of a specific bodily function”.
For example: The nervous system.
MULTICELLULAR ORGANISM
“An individual living thing
composed of many cells are called Multicellular organisms”.
For example: Pronghom antelope.
SPECIE
“A group of very similar inter
breeding organisms constitutes a species”.
For example Herd of pronghom antelope.
POPULATION
“Members of same species
inhabiting the same area are considered as population”.
For example: Herd of pronghom antelope.
COMMUNITY
“Population of several species
living and interacting in the same area form a community”.
For example: Snake, antelope and hawk.
ECO-SYSTEM
“A community with its
environment including land, water and atmosphere, constitute an eco-system”.
BIOSPHERE
“The part of earth inhibited by
living organisms, both living and non-living components.”
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