Question

Which one of the following statements about morula in humans is correct?

• A. It has almost equal quantity of cytoplasm as an uncleaved zygote but much more DNA
• B. It has far less cytoplasm as well as less DNA than in an uncleaved zygote
• C. It has more or less equal quantity of cytoplasm and DNA as in uncleaved zygote
• D. It has more cytoplasm and more DNA than an uncleaved zygote

Answer 1

The correct option is A It has almost equal quantity of cytoplasm as an uncleaved zygote but much more DNA

A morula is an embryo at an early stage of embryonic development, consisting of cells (called blastomeres) in a solid ball contained within the zona pellucida. The morula is produced by embryonic cleavage, the rapid division of the zygote. The increase in the number of cells doesn't change the size of the original mass. The divisions are rapid because there is no net growth of the embryo. In the absence of growth, the cell number in the embryo increases while the cell size decreases. Thus, it has an almost equal quantity of cytoplasm as an uncleaved zygote but much more DNA.