Question

Read statement ${}^{\prime }a$ to $d^{\prime }$ and find out how many is/are incorrect statement(s).
(a) In majority of the pteridophytes, all the spores are of similar kinds.
(b) Genera like Selaginella and Salvinia produce two kind of spore.
(c) The development of the zygote in the young embryos take place within the female gametophytes. This event is a precursor to the seed habit.
(d) Azolla is an aquatic fern that is used as biofertilizer due to the presence of nitrogen fixing cyanobacteria.

• A. $0$
• B. $1$
• C. $2$
• D. $3$

Answer 1

The correct option is A $0$

In majority of pteridophytes, all the spores are of similar kinds, such plants are called homosporous. Pteridophytes, which produce two kinds of spores, macro (large) and micro (small) spores are called heterosporous, e.g. Selaginella and Salvinia. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. The female gametophytes in these plants are retained on the parent sporophytes for variable periods. The development of the zygotes into young embryos take place within the female gametophytes. This event is the precursor to the seed habit which is considered as an important step in evolution.

The water fern Azolla harbors nitrogen-fixing. Cyanobacterium Anabaena azollae as symbiont is in it and is known as potent $N_2$ fixer. It is used as a biofertilizer.

Hence, all statements are correct.