Question

Cross-pollination is favoured by
(a) Self-sterility
(b) Dichogamy
(c) Herkogamy and heterostyly
(d) All of these

Answer 1

Hint: Cross-pollination is when a plant of another type is pollinated by one plant. A common technique used by hermaphroditic angiosperms to minimize sexual interference is one characteristic. Self incompatibility is another trait.

Complete answer:
The genetic material of the two plants is mixed in cross-pollination and the resulting seeds from that pollination would have characteristics of both varieties and are a new variety.

By cross-pollination, many numbers of species are pollinated. Unisexuality, dichogamy, self-sterility, mechanical and structural barrier, and heterostyle are the variables favoring cross-pollination.
- To avoid self-fertilization and improve family diversification, self-sterility in plants is enhanced.
- Dichogamy is the ripening of a flower's stamens and pistils at various times in order to avoid self-fertilization.
- Herkogamy is a common technique used by hermaphroditic angiosperms to minimize the role of male (anthers) and female (stigma) sexual interference.
- Heterostyly in flowers is a rare type of polymorphism and herkogamy. Two or three morphological forms of flowers in a heterostyle species occur in the population. All these avoid and favour cross-pollination from self-pollination.
So, the correct answer is, ‘(d) All of these’.

Note: Cross-pollination is the movement of pollen from one flower's anther to another flower's stigma to another of the same species' separate individuals.
Self-sterility or self-incompatibility is the phenomenon in which a plant is unable to conduct successful self-fertilization, i.e. by inhibiting pollen germination or the growth of pollen tubes on the pistil, prevents self-pollen from fertilizing the ovules. As fertilization does not occur, there is no creation of seeds.