Ques. 1AIPMT 2002
What is true for cleavage?
- Size of embryo decreases
- Size of embryo increases
- Size of cells increases
- Size of cells decreases
Answer
(4) Size of cells decreases
Solution
As per NCERT, the zygote undergoes mitotic divisions called cleavage as it moves through the isthmus of the oviduct towards the uterus and forms 2, 4, 8, 16 daughter cells called blastomeres.
∵ There is no growth between successive divisions, the overall size of the embryo stays nearly the same while it is divided into more and more cells,
∴ the size of the cells (blastomeres) decreases.
Answer: (4)