What is sex determination? State the different methods of sex determination in animals.

Explanation

The unisexual organism is either a male or a female. The mechanism by which the sex of an individual is determined is called sex determination.
The organism that develops from the fertilised egg (zygote) may be a male or a female offspring.
Methods of sex determination in animals : Different species of animals utilize different methods for their sex determination.
e.g., ( 1) In a few reptiles, the sex determination is dependent on the environmental factor, i.e., temperature. The egg (zygote) may develop into a male turtle or a female turtle, is determined by temperature.
When a temperature is over `30^(@)C`, the eggs of turtle, develop into female.
The eggs of crocodiles exposed to the high temperature induce the development of male whereas the lower temperature induces the development of female crocodiles.
( 2 ) In human beings the sex of the individual is determined by sex chromosomes and is thus genetically determined.
The genes inherited from parents decide the sex of the offspring.
Exception : The animal such as certain snail can change its sex. The sex therein, is not genetically determined.