Question

The female gametophytes are retained on the parent sporophyte in
A. Homosporous species of pteridophytes
B. Heterosporous species of pteridophytes
C. Both are correct
D. Both are incorrect

Answer 1

Pteridophytes are seedless, vascular plants and reproduce through spores that are developed in the sporangia. They show the true alternation of generations. Based on the similarity between spores, pteridophytes may be homosporous or heterosporous.

Complete answer:
Pteridophytes are known to reproduce through the production of spores which may be similar or different, hence, termed as homosporous or heterosporous. Most of the pteridophytes are known to produce similar kinds of spores while some of the pteridophytes belonging to the genera Salvinia and Selaginella are known to produce two different kinds of spores i.e., microspores and macrospores. The microspores give rise to male gametophyte after germination while the macrospores germinate to form female gametophyte. So, the female gametophyte is retained on the parent sporophyte in heterosporous species of pteridophytes.
Option (A) is incorrect because the homosporous species of pteridophytes never give rise to female gametophyte as they possess only similar kinds of spores. There is no differentiation between male and female gametophyte.
Both, Option (C) and (D) are not correct because, to retain the female gametophyte on the parent sporophyte, macrospores need to germinate into female gametophyte and these macrospores are not found in homosporous species of pteridophytes but are present in heterosporous species of pteridophytes.

So, the correct option is (B).

Note: Heterosporous species as the name indicates are known to produce two different kinds of spores i.e., micro and macrospores which germinate to form male and female gametophytes that are retained on the parent sporophyte.