Question

What do you understand by term migration?
(a)Movement of the organism or a group of organisms.
(b)Movement of natural habitat.
(c)Movement of an organism or a group of organisms from its natural habitat to another place at a particular time every year.
(d)All of the above

Answer 1

Hint: It is one of the factors that affect population growth by increasing the chances of survival of an organism. Few examples include the migration of birds in the spring and autumn. The colorful Greater Striped Swallow, Amur Falcon, white-rumped swift, etc are the birds that migrate to South Africa during autumn.

Complete answer:
Migration is a change of habitat periodically recurring and alternating in direction, which tends to secure optimum environment conditions at all times. Migration can be classified in following-
Latitudinal
Longitudinal
Altitudinal or vertical
Partial
Total
Vagrant or irregular
Seasonal
Diurnal
Nocturnal
Organisms migrate to escape from harsh environmental conditions which can reduce their rate of survival. It is a temporary and seasonal process. Organisms return to their original habitat after conditions become normal.

Additional Information: -Migration depends upon the amount of availability of food in an area to survive and raise their offsprings, so when there is a storage of food in one area they move to another area or the other reason is the change in temperature.
-Cuckoo breeds in India and spends the summer in southeast Africa and thus covers a distance of about 7250km which they migrate from north to south and vice versa termed as latitudinal migration.

So, the correct answer is, ‘Movement of an organism or a group of organisms from its natural habitat to another place at a particular time every year.’

Note: -In the late summer, the decrease in sunlight stimulates a migrating bird’s pituitary gland to produce hormone prolactin and its adrenal gland to produce the hormone corticosterone.
-These hormones cause the birds to accumulate large amounts of fat just under the skin, providing them with enough energy for the long migratory flight.