Question

Heterospory is found in
A) Funaria
B) Dryopteris
C) Marchantia
D) Selaginella

Answer 1

Hint:Heterospory is the formation of two spores of different size and sex on the same sporophyte land plant. The evolution of heterospory first took place in Pteridophytes.

Complete answer:
Let us analyse the options to find the correct answer.
>Option A:Funaria, also known as Moss belongs to phylum Bryophyta. Bryophytes are homosporous and also Funaria is found near water. Hence, this is an incorrect option.
>Option B: Dryopteris is a Pteridophyte but it is homosporous. It produces haploid spores 32-64 in number inside each of the sporangium. Hence, this is an incorrect option.
>Option C: Marchantia is a bryophyte and belongs to a group of Liverworts.Since Bryophytes are homosporous, they do not show heterospory. Hence, this is an incorrect option.
Option D: Selaginella is a Pteridophyte and heterospory first evolved in them. Two types of spores which >are different in size and function are produced. Smaller spore is called the microspore which forms male gametophyte and the larger spore is called megaspore which forms female gametophyte. Hence, this is the correct option.

Additional information:
>Evolution of heterospory has helped in the expression of sex determination during the sporophyte phase.
>It helps the plant to approach the seed habit.
>Numerous characteristic changes have taken place in spore development due to seed habit.
>Heterospory has helped in formation of endosporic gametophyte.

Thus, the correct answer is option (D) Selaginella.

Note:In Selaginella the number of megaspores produced in a megasporangium are more than the number of microspores produced in microsporangium.Pteridophytes that show Heterospory are Soetes, Stylites, Marsilea, Pilularia, Regnellidium, Salvinia, Azolla, and Platysma.