1) Ecology : Study of relationship of animals and plants with other organisms, inert objects and chemico-physical conditions in their environments.
(2) Morphology : Study of form and structure :
(a) External morphology : Study of shape, size, colour and external features.
(b) Anatomy : Study of gross structure of body and organs as revealed by dissection, and observed by unaided human eyes (size range 0.1 mm, i.e., 100 nm and larger).
(c) Histology : Study of tissues with the help of microscopes (size range 10 nm to 100 nm).
(d) Cytology : Study of cells from all aspects (size range 0.2 to 10 Hm).
(e) Microanatomy : Includes both Histology and Cytology.
(3) Craniology : Study of skull.
(4) Neurology : Study of Nervous system.
(5) Sarcology or Myology : Study of muscles.
(6) Haematology : Study of blood and blood diseases.
(7) Osteology : Study of skeletal system.
(8) Angiology : Study of vascular system.
(9) Odontology: Study of teeth.
(10) Organology : Study of organs.
(11) Syndesmology : Study of bone joints and ligaments.
(12) Karyology : Study of nucleus.
(13) Endocrinology : Study of endocrine system.
(14) Physiology : Study of functions of different parts of body.
(15) Tectology : Study of structural organization of body.
16) Ethology : Study of animal habits and behaviour.
(17) Embryology : Study of formation and development of embryos.
(18) Ontogeny : Study of the history of development of an organism.
(19) Phytogeny : Study of evolutionary history of a species or a larger group of organisms.
(20) Taxonomy : Study of animal and plant classification and nomenclature.
(21) Evolution: Study of the origin of new species by diversification of older ones.
(22) Ctetology : Study of acquired characters of animals and plants.
(23) Palaeontology : Study of animal and plant fossils.
(24) Genetics : Study of hereditary characters and their inheritance.
(25) Zoogeography : Study of geographical distribution of animals on the earth.
(26) Eugenics : Study of improvement of human race by means of principles of Genetics.
(27) Euthenics : Study of improvement of human race by providing better conditions of life, i.e., nurture.
(28) Euphenics : Study of improvement of human race by altering the proteins during mRNA —> protein synthesis process in cells. This is also called Medical Engineering.
(29) Radiobiology or Actinobiology : Study of effects t>f radiation on animal and plant bodies.
(30) Parasitology : Study of parasitic animals and plants.
(31) Pathology : Study of causes, nature and symptoms of diseases.
(32) Trophology : Study of food and nutrition.
(33) Toxicology : Study of toxic compounds (poisons) and their effects on animals and plants.
(34) Aerobiology : Study of flying animals.
(35) Limnology : Study of still-water bodies such as ponds, ditches, lakes, etc., from animal point cf view.
(36) Enzymology : Study of organic catalysts, i.e., the enzymes.
(37) Protozoology : Study of unicellular animals, i.e., protozoans.
(38) Helminthology : Study of parasitic worms—helminths.
(39) Entomology : Study of insects.
(40) Ichthyology : Study of fishes and fisheries.
(41) Herpetology : Study of amphibians and reptiles.
(42) Ornithology: Study of birds.
(43) Mammalogy : Study of mammals.
(44) Anthropology : Study of human evolution and culture.
(45) Malacology or Conchology : Study of molluscs and their shells.
(46) Ophiology : Study of snakes.
Using modern technology, scientists have now opened certain new aspects of animal biology, and have, thus, established some modern branches such as :
(47) Biochemistry: Study of chemistry of animal and plant bodies.
(48) Biophysics : Study of animal and plant activities on basis of principles of Physics.
(49) Serology : Study of blood serum.
(50) Immunology: Study of defense and resistance of animal body to infection.
(51) Psychobiology: Study of animal psychology.
(52) Molecular biology : Study of animal and plant chemistry at molecular level.
(53) Microbiology : Study of micro-organisms. Includes Bacteriology for study of bacteria and Virology for study of viruses.
(54) Gerontology : Study of ageing and old age in man.
(55) Teleology : Study of interpretations of structure in terms of purpose and utility.
