Which of the following is a useful method to store pollen grains?

$A$ long pollen tube is found in $.......$.

Which of the following stimulates pollen germination and pollen tube growth?

In which cell of the embryo sac are the male gametes released?

How many of the following statements are true about the figure given below?
i. Germination of pollen grain.
ii. Motile male gametes.
iii. Two male gametes and one female gamete.
iv. Pollen grain without exine.
v. Tube nucleus at the tip of pollen tube.

Where does the pollen tube develop?