Question

If the first cleavage furrow divides the zygote completely into two, the cleavage type is

• A. Radial
• B. Equatorial
• C. Meroblastic
• D. Holoblastic

Answer 1

The correct option is D Holoblastic

When the cleavage furrow passes through the embryo's midsection, then it is equatorial cleavage.
Radial cleavage is a type of holoblastic cleavage where the blastomeres are arranged in a radial symmetry, i.e., the upper tier lie directly over those of the next lower tier.
In meroblastic cleavage, the cleavage furrow does not divide the egg completely.
In holoblastic cleavage, the furrow divides the egg completely into two. Blastomeres are formed by the holoblastic cleavage and they may be equal or unequal in size.
Thus, the correct answer is option D.