zoology

Branch of biology concerned with the study of animals. It includes any aspect of the study of animal form and function - description of present-day animals, the study of evolution of animal forms, anatomy, physiology, embryology, behaviour, and geographical distribution.

Aspects of zoology Histology is the microscopic study of animals' cells and the different tissues made up of these cells. Cytology studies the interior of the cells and how their organelles function. Comparative anatomy compares the structure of various groups of animals to see how they are related to each other, and contributes to the study of evolution, which is concerned with how modern animals developed and what primitive ancestors they have evolved from.

Studies of reproduction, growth, and development include embryology and genetics. How animals function is studied through biochemistry, cytology, and physiology, all of which help zoologists to understand the workings of the animal's body. The relation of the animal to its surroundings is studied in ecology and animal behaviour or ethology. The classification of animals, how each group is related to the others, is studied in taxonomy.

Related fields Since many processes of life are common to plants and animals, the fields of zoology, botany, and biology cannot clearly be separated. All forms of life need to take in oxygen, food, and water and give out waste products, to grow and reproduce. Each organism has found a niche in which it can live and certain ways of carrying on the processes of life. Zoologists try to understand how all animals have solved these problems, from the one-celled protozoa to the close relatives of humans, the primates.