Question

What is ploidy of nucellus,MMC,functional megaspore,female gametophyte?plz explain how?

Answer 1

nucellus-it is the layer enclosed within the integuments. its cells have abundant reserve food which helps in providing energy during megasporogenesis  to mmc. so, its ploidy is same as that of other cells in the plant.
and we know that plants are diploid.  hence its  ploidy is 2n
mmc - it is a meiocyte cell which undergo meiotic division to giverise to the female gamete(n) so, its ploidy is also 2n
functional megaspore-
mmc undergo 1st meiotic division to give megasore dyad which further undergoes 2nd meiotic  division to give megaspore tetrad .
out of the 4 , 3 of them degenerate and one remains functional i.e is the functional megaspore.
as it formed by meiosis (reductional division) so its ploidy is half the ploidy of mmc
ie 2n/2 = n
female gametopyte - it is nothing but the female gamete.
it is universal fact that the gamete are haploid so, ploidy of female gametopyte is n

Answer 2

Dear Students,

◆ Answers -

• Nucellus => Diploid (2n)
• Megasore mother cell => Diploid (2n)
• Functional megaspre => Haploid (n)
• Female gametophyte => Haploid (n)

● Explanation -

• Basically, plants embryo are formed from male & female gametophyte, it's diploid in nature.
• Both nucellus & megaspore mother cell occur before meiosis, thus reatain diploidy.
• Whereas functional megaspore & female gametophyte are observed after meiosis, thus become halpoid.

Hope I was useful..