Question

Pollination occurs in
A. Bryophytes and angiosperms
B. Pteridophytes and angiosperms
C. Angiosperms and gymnosperms
D. Angiosperms and fungi

Answer 1

Hint: The goal of every living thing, including plants, is to produce offspring. In plants it can be achieved by pollination only. We all know that pollination occurs in different plants in the presence of external agents like wind, water, animals etc.

Complete answer:
Pollen is a powdery substance consisting of pollen grains which are male microgametophytes of seed plants, which produce male gametes.
Pollen grains are immobile. They can not reach the stigma by themselves and hence require external reagents. It can be an abiotic agent or a biotic agent. The transfer of pollen grains from the anther to the stigma, whether of the same flower or of a different flower, is called pollination.
It was first reported by Kolreuter. Among plants, pollination occurs only in Gymnosperms and angiosperms. In Gymnosperms, pollination is direct as pollen is transferred to the micropyle of the ovule directly by wind. In angiosperms, pollination is indirect as ovules are enclosed in the ovary. Pollen first reaches stigma and then to ovule by various pollinating agencies.

So, the correct answer is option C, Angiosperms and gymnosperm.

Additional information:
Charles Darwin in his book "Good effects" of intercrossing stressed upon the benefits of cross pollination to the plants.
ADVANTAGES:
1. A number of plants are self- sterile, pollen grains cannot complete growth on the stigma of the same flower due to mutual inhibition or incompatibility.
2. Cross pollination introduces genetic recombination and hence variations in the progeny.
3. The seeds produced are usually larger and the offspring have characters better than the parents due to the phenomenon of hybrid vigor.
4. The defective characters of the race are eliminated and replaced by better characters.
5. It makes the organism better fitted in the struggle for existence.
5. Yield never falls below an average minimum.

DISADVANTAGES:
1. A factor of chance is always involved in cross pollination.
2. It is less economical.
3. Some undesirable characters may creep in the race.
4. The very good characters of the race are likely to be spoiled.

Note-
Living organisms are designed to ensure the survival of the progeny. Genetic diversity is needed for the survival of the progeny even in the adverse conditions. Self- pollinated plants produce less genetic diversity because the genetic material of the same plant is used to form the gamete. Contrary to this, in cross pollinated plants greater genetic diversity is seen as gametes are formed from different plants. Because cross pollination helps in forming more genetic diversity, plants have developed many ways to avoid cross pollination.