The term used for transfer of pollen grains from anthers of one plant to stigma of a different plant which during pollination, brings genetically different types of pollen grains to stigma, is:
In water hyacinth and water lily, pollination takes place by:
1. Water currents only
2. Wind and water
3. Insects and water
4. Insects or wind
Which of the following is incorrect for wind-pollinated plants?
1. Well exposed stamens and stigma
2. Many ovules in each ovary
3. Flowers are small and not brightly colored
4. Pollen grains are light and non-sticky
What type of pollination takes place in Vallisneria?
|1.||Pollination occurs in submerged conditions by water.|
|2.||Flowers emerge above the surface of water and pollination occurs by insects.|
|3.||Flowers emerge above the water surface and pollen is carried by the wind.|
|4.||Male flowers are carried by water currents to female flowers at the surface of the water.|
In which one of the following, both autogamy and geitonogamy are prevented?
Given below are two statements:
I: Cleistogamous flowers are invariably autogamous
II: Cleistogamy is disadvantageous as there is no chance for cross pollination
In the light of the above statements, choose the correct answer from the options given below:
1. I is incorrect but II is correct
2. Both I and II are correct
3. Both I and II are incorrect
4. I is correct but II is incorrect
Bee-keeping helps to improve the yield of following crops Except ____________.