Question

Polygonum type of embryo sac/ typical female gametophyte of angiosperms is?

• A. $7$-celled, $7$-nucleate
• B. $7$-celled, $8$-nucleate
• C. $8$-celled, $7$-nucleate
• D. $8$-celled, $8$-nucleate

Answer 1

Answer: (B)

$7$-celled, $8$-nucleate

In the first mitotic division megaspore forms two nuclei. one is function that is chalazal end and other is micropylar. These nuclei are redivided to form eight nucleate stage. This is called as egg apparatus.At the chalazal end 3 out of 4 differentiates as antipodal cells and other two are moved toward nuclei .Hence, at maturity the female gametophyte appears as 7-celled structure and it has 8 nucleates.

Correct option is B.