Which one of the following statements is not true about the arrangement of cells in the embryo sac?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Three cells are grouped together at the chalazal end and constitute the egg apparatus.
The mature embryo sac (female gametophyte) has its cells in a fixed arrangement. At the micropylar end is the egg apparatus (two synergids and one egg cell). At the chalazal end are the three antipodal cells. In the middle is a large central cell with two polar nuclei.
(1) At maturity, a typical angiosperm embryo sac is an 8-nucleate, 7-celled structure. — True. There are 8 nuclei but only 7 cells, because the central cell holds two polar nuclei.
(2) The egg apparatus consists of two synergids and one egg cell. — True. These three cells form the egg apparatus.
(3) Three cells are grouped together at the chalazal end and constitute the egg apparatus. — Not true. The ends are reversed. The egg apparatus is at the micropylar end. The three cells at the chalazal end are the antipodals.
(4) The large central cell has two polar nuclei. — True. The two polar nuclei lie in the central cell, below the egg apparatus.
NCERT Extract:
The Pistil, Megasporangium (ovule) and Embryo Sac – …
