Reproduction in Organisms Question 10
10. What is true for cleavage?
[2002]
(a) Size of embryo increases
(b) Size of cells decrease
(c) Size of cells increase
(d) Size of embryo decreases
Show Answer
Answer : b
Hints & Solutions
(b) Cleavage involves repeated cell division without increase in size. But cell size decreases. In placental mammals (including humans) where nourishment is provided by the mother’s body, the eggs have a very small amount of yolk and undergo holoblastic cleavage. Other species, such as birds, with a lot of yolk in the egg to nourish the embryo during development, undergo meroblastic cleavage.
