1
Question
In which of the following animal cleavage, divisions are restricted to a small part of cytoplasm and nucleus in animal pole of egg?
In which of the following animal cleavage, divisions are restricted to a small part of cytoplasm and nucleus in animal pole of egg?
Open in App
Solution
The correct option is C Chick
The telolecithal eggs of reptiles and birds have very large amounts of yolk at the vegetal pole and only a small amount of cytoplasm concentrated at the animal pole. The yolk of such eggs never cleaves. Cell division is restricted to the blastodisc, the small disc of cytoplasm at the animal pole; this type of cleavage is termed meroblastic cleavage. In birds and some reptiles, the blastomeres form two layers separated by the blastocoel cavity: an upper epiblast and a lower, thin layer of flat cells, the hypoblast.
The telolecithal eggs of reptiles and birds have very large amounts of yolk at the vegetal pole and only a small amount of cytoplasm concentrated at the animal pole. The yolk of such eggs never cleaves. Cell division is restricted to the blastodisc, the small disc of cytoplasm at the animal pole; this type of cleavage is termed meroblastic cleavage. In birds and some reptiles, the blastomeres form two layers separated by the blastocoel cavity: an upper epiblast and a lower, thin layer of flat cells, the hypoblast.
Suggest Corrections
0
Similar questions
View More
Join BYJU'S Learning Program
Explore more
Join BYJU'S Learning Program
