Question

Read the following five statements (A to E) and select the option with all correct statement
(A) Mosses and Lichens are the first organisms to colonize a bare rock.
(B) Selaginella is a homosporous pteridophyte.
(C) Coralloid roots in Cycas have VAM.
(D) The main plant body in bryophytes is gametophytic whereas in pteridophytes it is sporophytic.
(E) In Gymnosperms, male and female gametophytes are present within sporangia located on sporophytes.

A. (A), (D) and (E)
B. (B), (C) and (D)
C. (A), (C) and (D)
D. None of these

Answer 1

Pioneer community is the one which arises first on a bare rock or land. Bryophytes have diploid sets of chromosomes while pteridophytes have haploid sets of chromosomes.

Complete answer:
Mosses and lichens belong to the pioneer community. They are the first organisms to colonize a bare rock. The main plant body of bryophytes is gametophytic means they have two sets of chromosomes. They are non-vascular that is xylem and phloem are not present. Their body is thalloid. In contrast, the pteridophytes are sporophytic plants. They are also known as vascular plants as xylem and phloem are present in them. Their body is divided into roots, stems and leaves. They have one set of chromosomes. Gymnosperms are seed bearing plants. They often bear naked seeds. Also, in Gymnosperms, male and female gametophytes are present within sporangia located on sporophytes. This implies that statements A, D and E are correct.
However, statement B and C are not correct. Although Selaginella belongs to pteridophytes but they are heterosporous, that is spores are differentiated into males and females. Moreover, VAM is a type of fungus which enters the roots of the plants via penetration and thus starts absorbing the plant nutrients but in the roots of Cycas, cyanobacteria are present, not VAM.

Hence, the correct answer is option (A).

Note: Species of Selaginella consists of ascendant plants. They belong to creepers. They are vascular plants having xylem and phloem and their body is divided into roots, stems and leaves. In Cycas, development of coralloid roots takes place at the base of the stem. It is of greenish brown color showing dichotomous branching. In the cortex region of these roots, an algal zone is present consisting of Nostoc and Anabaena.