Question
Biology Question on Structural Organisation of Animals and plants
Blastopore in frog development occurs in
blastula and opens into eccentric blastocoel
blastula and opens into archenteron
gastrula and opens into blastocoel
gastrula and opens into gastrocoel
gastrula and opens into gastrocoel
Solution
In frog, the gastrulation starts by the deformation of certain prospective endodermal cells in a circumscribed area below the equator or in border line of the vegetal region and exactly below the grey crescent of blastula. These cells assume elongated shape and move towards the interior of the blastula. With continued multiplication and attenuation of the cells, the invagination deepens. This causes the formation of a crescentric slit or groove upon the dorsal surface of the vegetaJ hemisphere. This slit is the beginning of blastopore. Blastopore forms an external opening for the gastrocoel and marks the posterior end.