Question

1. What is the function of the annulus? How does dehydration allow it to perform this function?

2. How are bryophyte and monilophyte gametes dispersed? How are the spores dispersed? Why do they need a moist environment in order to carry out sexual reproduction?

Answer 1

Question

1. The annulus is present in the leptosporangiate ferns and their function is to help the spore dispersal. The annulus is situated on the outer rim of the sporangium. When the annulus get dehydrated or dried out, the cell contract and assist in the rupturing of sporangium which help in the release of spores or spore dispersal.

2. The spores are dispersed through wind in case of bryophytes and gametes in monilophyte are dispersed through animals, water and gravity. The gametes are dispersed through water in bryophytes and by wind in monilophyte. They need water to carry out sexual reproduction because the egg in these plants are non-motile which are fertilized by flagellated sperm.