Question

38. (a) What changes are observed in the
uterus if fertilisation does not occur.
[b]What would be the ratio of
chromosomes number between an egg and its
zygote? How is the sperm genetically different
from the egg?​

Answer 1

❖a)

Uterus every month prepare itself to receive a fertilised egg for implantation by making it's walls thick and spongy. If fertillisation does not occur then uterus keep the unfertilized egg for 2 days and after then this thick wall shed off and come out through vagina as blood and mucus. ❖

❖b)

Egg is haploid in nature and have 23 chromosomes while zygote is diploid in nature having 46 chromosomes, SO,

Ratio will be 1 : 2.❖

Sperm is genetically different from egg because egg is homogametic having both X chromosomes while Sperm is heterogametic containing ( two different) X and Y chromosomes.