after pollination, if the 2-celled pollen grain comes across dry stigma, then there will not be germination of pollen grain. Give reason.
Answers
The stigma is generally moist and sticky or hairy in structure so that when the pollen grains fall on them they can get easily adhered to the stigma.
If the pollen grain comes in contact with a stigma which is dry and not sticky, the stigma will be unable to trap the pollen grain, as a result of which fertilization will not take place.
Reason why there will be no germination of pollen grain after pollination:
A stigma has a chemical which is sticky, moist and hairy like structure which helps the pollen grains to grow and form a pollen tube for fertilization. This sticky material helps the pollen grains to become fertilized. But if the stigma is dry and when the pollen grains comes near to stigma but stigma is unable to catch the pollen grains so the fertilization will not take place in dry stigma.