Question

The blastula of reptiles and birds is known as

• A. Coeloblastula
• B. Discoblastula
• C. Superficial
• D. None of the above

Answer 1

Answer: (B)

Discoblastula

Discoblastula, a blastula formed from the partial cleavage that occurs in a fertilized ovum containing a large amount of yolk. It develops from the blastodisc and consists of a cellular cap, or blastoderm, separated from the uncleaved yolk mass by a small cavity, the blastocoel. This type of cleavage is seen in reptiles and birds.

Coeloblastula is a blastula formed as a result of complete holoblastic cleavage. It is formed in echinoderms and Amphioxus.

Superficial blastula is one which shows the absence of blastula and is formed as a result of superficial cleavage.

Amphiblastula is formed in amphibians as a result of two structurally different blastomeres.

Thus, the correct answer is option B.