Question

Read the following five statements ( A to E ) and select the option with all correct statements.

(A) Mosses and Lichens are the first organisms to colonize 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 sporophyte.

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

Answer 1

The correct option is A (A), (D) and (E)

• The thalli of lichens can adhere to the surface of the rock and absorb moisture from the atmosphere; therefore, these colonize the bare surfaces of rocks first. These lichens produce acids that corrode the rock and their thalli collect windblown soil particles among them that help in formation of a thin film of soil.
• The adult plant body of bryophyte represents the gametophyte. A short-lived sporophyte occurs as a parasite on the gametophyte. In gymnosperms, a leafy green sporophyte generates cones containing male and female gametophytes; female cones are bigger than male cones and are located higher up in the tree.
• The coralloid roots contain symbiotic cyanobacteria (blue-green algae), which fix nitrogen and, in association with root tissues, produce such beneficial amino acids as asparagine and citrulline.
• Hence the correct option is A.