Botany - Sexual Reproduction in Flowering Plants Question with Solution | TestHub
From the statements given below choose the option that is true for a typical female gametophyte of a flowering plant:
i. It is 8-nucleate and 7-celled at maturity.
ii. In majority of the angiosperms, it is monosporic.
iii. It is situated inside the integument but outside the nucellus.
iv. It has an egg apparatus situated at the micropylar end.
v. It develops by mitosis of the 4 cells of megaspore tetrad.
Options:
Answer:
Solution:
Typical female gametophyte develops when one of the cells in the ovule towards microphylar end become megaspore mother cell (2n) and undergoes meiosis to form one functional megaspore(n) and three non-functional/ degenerative megaspore(n) arranged in linear tetrad form. This functional megaspore(n) undergoes three successive, free nuclear division to form 7 celled and 8 nucleated female gametophyte. Out of these seven cells, three antipodal cells arrange itself at chalazal end, central cell arranges near the centre of embryo sac and egg apparatus (one egg cell and two synergids) is situated at the micropylar side. Embryo sac/ female gametophyte is surrounded by nucellus which in turn is protected by integuments.
