Question

The main plant body of pteridophytes is
A. Sporophyte
B. Gametophyte
C. Haploid
D. None of the above

Answer 1

Pteridophytes are vascular plants that have the main plant body differentiated into leaves, roots, and sometimes true stem, which is diploid. Their life cycle shows true alternation of generation having both phases i.e, gametophytic as well as sporophytic that are independent at maturity.

Complete answer:
Option (A) is correct. The sporophyte is the main plant body of pteridophyte because it is a diploid multicellular stage that differentiates into true root, stem, and leaves. The sporophyte develops from the zygote which is formed by the fusion of haploid male gamete with the haploid female gamete.
Option (B) is incorrect. The free-living gametophyte phase in pteridophytes produces gametes by the mitotic division because the gametophyte phase is haploid. The gametes thus produced will then fuse to form a zygote which later on, forms the sporophytic phase of pteridophyte i.e., the main plant body of pteridophytes.
Option (C) is incorrect. The main plant body of pteridophyte is not haploid but it is diploid because it develops from the diploid zygote.
Option (D) is incorrect. The alternative “none of the above” cannot be right, since one of the options is correct, i.e. option (A).

Hence, the correct answer is option (A).

Note: The sporophyte phase of pteridophyte is diploid that forms the main plant body of pteridophytes. This phase produces spores through the meiotic division that germinate to form the gametophytic phase i.e., haploid. The gametophytic phase produces haploid gametes through the mitotic division which then fuse to form the diploid zygote that will further form the diploid sporophytic phase. Hence, pteridophytes show alternation of generation.