The researches using modern techniques and electron microscope widely enriched the zoology. The some of the main branches are as follows

1. Taxonomy – Systematic study of the animals is called as classification. The study of classification and nomenclature of the animals is called as taxonomy. 

2. Morphology – It deals with the study of size and external features of the animals 

3. Anatomy – The study of internal structure of the animals. The study of internal tissues is called as histology. 

4. Genetics – Study of the process of transmission of Characters (genes) from generation to generation is called as genetics. 

5. Physiology- The study of functioning of body organs and organ system is called as physiology. Such as physiology of digestion, respiration etc. 

6. Embryology – It deals with the study of embryonic development i.e. formation of young one from the zygote. 

7. Evolution – This branch deals with the process of origin of life, origin of species and differentiation. 

8. Ecology – Study of interaction between animals and their environment 

9. Biotechnology – The exploitation of biological processes, especially the genetic manipulation (DNA trimming) of organisms to obtain desired products. 

10.Paleontology – The study of fossils is called as paleontology. The preserved remains or traces of animals, plants & other organisms from the remote past are called as fossils. 

11.Zoo-geography – Study of geographical distribution of the animals on the earth. 

12.Eugenics – The study of improvement of human race with the help of genetics is called as eugenics. This term was coined by Sir Francis Galton.