Question

Select the correct statements regarding the structure of a mature embryo sac.

a) Egg apparatus consists one egg cell and two synergids.
(b) Antipodals cells are situated towards micropylar end.
(c) Polygonum type of embryo sac is most common type in angiosperms.
(d) Polar nuclei are situated below the egg apparatus in the larger central cell.

• A. (a), (b) and (c)
• B. (b), (c) and d
• C. Only (a) and (c)
• D. (a), (c) and (d)

Answer 1

The correct option is C Only (a) and (c)

In flowering plants, the embryo sac is small-sized and consist of seven cells and eight nuclei. The cell closest to the micropyle opening of the integuments differentiated into egg cell with two synergies cells. Three antipodal cells form on the opposite end i.e chalazal end of the ovule. The large central cell of the embryo sac contains two polar nuclei.

In angiosperm polygonum type of embryo sac is most common in polygonum type embryo sac meiosis occurs in diploid mother cell in the nucellus which produces four haploid megaspore. Three of megaspore usually which are present at the micropyle end of nucellus undergoes programmed death so we get only one functional megaspore.

Thus, 'Only (a) and (c)' is the correct answer.