Question

Which among the following is a prerequisite in Selaginella to exhibit seed habit?

• A. Heterophylly
• B. Heterospory
• C. Microphylly
• D. Creeping stem

Answer 1

The correct option is B

Heterospory

Selaginella has many features which are required for the formation of seed. They are collectively called seed habit of Selaginella. These features include (i) heterospory, (ii) formation of two types of gametophytes, (iii) gametophytes are nutritionally dependent on parent sporophyte, (iv) gametophytes show precocious development which is also endosporic, (v) formation of one functional megaspore mother cell in a megasporangium, (vi) occassional presence of a single megaspore in a megasporangium, (vii) formation of integument over the megasporangium, (viii) retention of megaspores inside partially opened megasporangia and growth of male gametophyte near the female gametophyte, even fertilisation and development of embryo occurs there. However, seed formation does not occur.