Read the following statements (A - E) and answer the question which follows them.
(A) In liverworts, mosses, and ferns gametophytes are free living .
(B) Gymnosperms and some ferns are heterosporous.
(C) Sexual reproduction in Fucus, Volvox and Albugo is oogamous.
(D) The sporophyte in liverworts is more elaborate than that in mosses.
(E) Both Pinus and Marchantia are dioecious.
How many of the above statements are correct?
Liverworts and mosses are bryophytes. Their spores germinate to form free- living gametophytes.
Ferns belong to pteridophytes. Their spores germinate to give rise to inconspicuous, small but multicellular, free-living, mostly photosynthetic thalloid gametophytes (thalloid).
In majority of the pteridophytes all the spores are of similar kinds; such plants are called homosporous. Genera like Selaginella, Azolla and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous.
Gymnosperms are heterosporous; they produce haploid microspores and megaspores; these spores germinate and give rise to reduced male and female gametophytes.
Fusion between one large, nonmotile (static) female gamete and a smaller, motile male gamete is termed as oogamous reproduction, e.g., Volvox, Fucus, Albugo candida.
Sporophyte of liverworts and mosses is differentiated into a foot, seta and capsule. But the sporophyte in mosses is more elaborate than that in liverworts. Mosses have an elaborate mechanism of spore dispersal which is aided by the presence of peristomial teeth.
Pinus is monoecious but Marchantia is dioecious.
Therefore, statement A, B and C are correct.