Solved Examples on Plant Kingdom

(1) In angiosperms, functional megaspore develops into [CBSE PMT’2011M]

(a) Embryo sac

(b) Ovule

(c) Endosperm

(d) Pollen sac

Answer: a

Solution:

During megametogenesis functional megaspore (most chalazal) gives rise to embryo sac. This is the mature female gametophyte generation.

(2) Cycas and Adiantum resemble each other in having [CBSE PMT’2012M]

(a) Seeds

(b) Motile Sperms

(c) Cambium

(d) Vessels

Answer: b

Solution:

Cycas (a gymnosperm) and Adiantum known as Maiden hair fern is a pteridophyte resemble each other in having motile sperm. Seeds, cambium are common in gymnosperms and absent in pteridophytes. True vessels are absent in both pteridophytes and gymnosperms.

(3) Gymnosperms are also called soft wood spermatophytes because they lack [CBSE PMT’2012M]

(a) Cambium

(b) Phloem fibres

(c) Thick-walled tracheids

(d) Xylem fibres

Answer: d

Solution:

Gymnosperms lack thick walled tracheids rendering them soft-wood because tracheids impart strength to wood. Tracheids are the elongated cells in xylem.