Selaginella and Salvinia are considered to represent a significant step towards evolution of seed habit because

• female  gametophyte is free and gets dispersed like seeds

• female gametophyte lacks archegonia

• megaspores possess endosperm and embryo surrounded by a seed coat

• the embryo develops in female gametophyte which is retained on the parent sporophyte

What is the basis of classification of algae?

When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm and an angiosperm?

Name three groups of plants that bear archegonia. Briefly describe the life cycle of any one of them.

Mention the ploidy of the following: protonemal cell of a moss; primary endosperm nucleus in dicot, leaf cell of a moss; prothallus cell of a ferm; gemma cell in Marchantia; meristem cell of monocot, ovum of a liverwort, and zygote of a fern.

Write a note on economic importance of algae and gymnosperms.

Both gymnosperms and angiosperms bear seeds, then why are they classified separately? 

What is heterospory? Briefly comment on its significance. Give two examples.

Explain briefly the following terms with suitable examples:
(i) protonema
(ii) antheridium
(iii) archegonium
(iv) diplontic
(v) sporophyll
(vi) isogamy

Differentiate between the following:
Red algae and brown algae

Differentiate between the following:
liverworts and moss