12 Biology Organisms and Populations - Set No : 21 Question No :6
Question No : 6
| Periodic departure and return of an individual in a population is known as |
| a) | Immigration | b) | Migration |
| c) | Emigration | d) | Mutation |
Answer No : 6
(b)Migration
It is the temporary
departure and return of organism due to unfavourable condition of the
environment  bird migration from Siberia and
other extremely cold Northern regionWhereas,
immigration and emigration are the permanent phenomena |