A mature pollen grain is typically released in a desiccated state. As such, which of the following must a receptive stigma provide in order for a pollen tube to fertilise an ovary, and why?
A) Water, so that the pollen grain can resume metabolic activity.
B) Nutrients, as pollen grains typically carry no energy reserves.
C) Anti-fungal compounds to prevent the pollen grains being broken down by plant pathogens.
D) Phyto-hormones to attract the pollen grain vector to the stigma.
E) A physical barrier to prevent the pollen grain being eaten by birds and insects.

Question

Quizplus · Accepted Answer

Water is essential for a pollen grain to resume metabolic activity once it lands on a receptive stigma. This rehydration process is critical for the pollen to germinate and for the pollen tube to grow towards the ovary for fertilization.

A Mature Pollen Grain Is Typically Released in a Desiccated