Module: | Pre-fertilization: Micro/Megasporogenesis
Q15: Consider the following statements regarding pollen-pistil interaction:
1. Pollen-pistil interaction is a dynamic process involving pollen recognition followed by promotion or inhibition of the pollen.
2. The chemical components of the pollen interacting with those of the pistil mediate this dialogue.
3. Only compatible pollen grains of the same species are physically able to land on the stigma under natural conditions.
Which of the above statements is/are correct?
2. The chemical components of the pollen interacting with those of the pistil mediate this dialogue.
3. Only compatible pollen grains of the same species are physically able to land on the stigma under natural conditions.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, but Statement 3 is incorrect.
Pollen-pistil interaction encompasses all events from pollen deposition on the stigma until pollen tube entry into the ovule.
It is causally mediated by a continuous chemical dialogue between proteins and specific compounds present in the pollen wall and the stigmatic surface.
This dynamic recognition system allows the pistil to accept compatible pollen (promoting germination) and reject incompatible pollen (inhibiting tube growth). Statement 3 is fundamentally flawed regarding natural ecological environments: wind and insects are indiscriminate carriers.
Pollen from completely different, wrong species routinely lands on the stigma.
The biological filter is not in preventing the landing, but in the post-pollination chemical rejection that stops inappropriate pollen from germinating or penetrating the style.
Pollen-pistil interaction encompasses all events from pollen deposition on the stigma until pollen tube entry into the ovule.
It is causally mediated by a continuous chemical dialogue between proteins and specific compounds present in the pollen wall and the stigmatic surface.
This dynamic recognition system allows the pistil to accept compatible pollen (promoting germination) and reject incompatible pollen (inhibiting tube growth). Statement 3 is fundamentally flawed regarding natural ecological environments: wind and insects are indiscriminate carriers.
Pollen from completely different, wrong species routinely lands on the stigma.
The biological filter is not in preventing the landing, but in the post-pollination chemical rejection that stops inappropriate pollen from germinating or penetrating the style.