Question

Some flowers are unisexual, this property of unisexuality of flowers prevents which kind of pollination ?

Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow. Note : All plants belong to the same species. × — No pollen tube growth/inhibition of pollen germination on stigma. ✓ — Pollen germination on stigma.

Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow.

Select the statements that are true for outbreeding devices in the flowering plants. (i) They discourage cross-pollination and ensure self-pollination. (ii) They are advantageous as they lead to inbreeding depression. (iii) Self-incompatibility prevents self-pollen from fertilising the ovules. (iv) To prevent self-pollination in some species pollen release and stigma receptivity are not synchronised. Choose the correct answer :