Zoology

Achievements in Zoology1665 Coined the term cell, Robert Hooke.1772 Observed free cells in bacteria, protozoans etc., A.V. Leeuwenhoek.1824 Animals and plants are aggregate of cells, Rene Dutrochet.1831 Round shaped nucleus, Robert Brown.1839 Applied cell theory of animals, T. Schwann.1861 Defined cells as living substance, Schutze.1882 Cell division in animals, W. Fleming.1886 Discovered cytochromes, Mac Munn.1902 […]

Zoology is an important branch of biology. This chapter describes some important terms used in zoology.Adaptations : The structural, functional and behavioural changes developed in living organisms over long period of time to adjust to specific environment for survival.Aggregation : An act of collection or getting together.Anabolism : Synthesis of complex molecules from simpler ones.Ageing

Environment : Plants, animals, viruses, microbes and non living things such as light, heat, soil, air, water houses and minerals constitute our environment.Composition of airNitrogen 77.17%Oxygen 20.60%Carbondioxide 0.03%Water Vapour 1.40%Argon and other gases 0.94%Others 0.80%Biosphere : All the biomes taken together as a bigger unit constitute a single large self-sustaining biological system called biosphere. It

Microbiology : It deals with the study of micro-organisms such as viruses, bacteria and other micro-organisms.Bacterium (pl. Bacteria) : This is a unicellular organism that lacks a nucleus and cytoplasmic organelles other than ribsomes, reproduces by binary fission and occurs in one of three shapes (rod, sphere, spiral). Bacteria are our friends and foes. They

Biotechnology deals with the use of living organisms or substances obtained from living organisms in industries to get useful products. It is comparatively a new branch which includes biology and technology.Usefulness of Biotechnology(i) Alcoholic Drinks : Wine, whisky, beer etc. are prepared by biotechnological methods.(ii) Dairy Products : Curd, cheese, butter etc. are prepared by

Biochemistry : The study of chemicals in relation to living organisms is known as biochemistry. In biochemistry many chemicals are studied. These are as follows:Acid : It is a compound tending to raise the hydrogen ion concentration in a solution and lowering its pH numerically.Base : A compound tending to lower the hydrogen ion concentration

Wild LifeWild life includes not only lion, tiger, wolves but also all animals living in natural environment. All forest plants, micro-organisms are included in wild life.Importance of Wild life conservation(i) Wild life conservation preserves environment.(ii) All food chains use maintained.(iii) Wild animals act as gene banks.(iv) Men’s greediness of hunting wild animals has been the

Smoking, drinking and taking narcotics are the habit cultivat substances in some persons due to family tensions and unbearable causes. When one becomes habitual of these things, we call it addiction. Giving off such habbits is very difficult. There may be many other causes for the addiction of these substances. We describe different kinds of

When the normal functioning of an organ or a system is hampered, it is said to be diseased. Diseases are caused by following agents.1. Pathogens : When virus, bacteria, fungi, protozoan, helminthes attack the body they cause diseases.2. Malnutrition : Deficiency of minerals, vitamins, proteins, fats, etc. in the body causes diseases. These are called

It is that branch of Zoology which contributes in the uplift of economy of a nation. Under economic zoology come—(i) Poultry(ii) Fisheries(i) Poultry : The demand of the poultry products have increased many times during the last 20 years. Poultry provides poultry meat and eggs to the humans. Meat and eggs provide protein rich diet

Palaeontology : It is the study of fossils or the remains or organisms of past geological age. This includes palaeobotany (dealing with botanical fossils) and palaeozoology (dealing with zoological fossils).Fossils : Fossils are preserved remains of animals, plants or their parts found in the various layers of the earth’s crust or rocks. The word fossil

Origin TheoriesSeveral theories regarding the ‘origin of life’ have been put forward.1. Special Creation Theory :According to this theory universe was created by God in six days. This theory has been published in Bible.According to this theory—First day—Earth and heaven were created.Second day—Sky was created.Third day—Dry earth and plants were created.Fourth day—Sun, moon and stars

Man has existed on earth only for the last 50,000 years. It started from stone age some 20,000 years ago. About 6000 years ago the agricultural age started. Industrialization is about 200 years old only. After this the population growth has been very fast.Study of human population statistically is known as demography. Demography as a

Genetics : Genetics deals with the study of of inheritance. Every living organism inherits traits from parents. These traits are transferred from generation to generation. All living being have genetic characters.Bateson in 1905 used for the first time the term ‘Genetics’. Mendel is considered the father of genetics. Genetics was revised in 1900.Genetics can be

GrowthGrowth refers to a process in which size and weight of an organism increases. It is a characterstic of every living being. In the process of growth cells undergo wear and tear process upto maturity. The process of growth is fast. After maturity it becomes a gradual process and finally the organnism dies.Auxetic Growth :