ANATOMY

Detailed explanation-1: -Fourth and fifth cleavage are also vertical forming 16 celled zygote. These division is followed by two horizontal cleacage, one toward animal pole and other toward vegetal pole, resulting in 32 celled stage.

Detailed explanation-2: -The term morula is used to designate the ensuing stages of embryonic development (16, 32, and 64 cells). The morula is thus the product of the first cell cleavages, which result in practically no growth, because the daughter cells become smaller and smaller. The morula is like a solid ball.

Detailed explanation-3: -(B) Holoblastic unequal: It is the cleavage which produces unequal size of blastomeres. Example: frog egg, which contains a fair amount of yolk towards the vegetal pole. Because of the concentration of the yolk at the vegetal pole, the blastomeres formed in a different size.

Detailed explanation-4: -Basic Facts. Frogs have multiple stages in thier life cycle: egg, tadpole, tadpole with legs, froglet, frog.

Detailed explanation-5: -Blastulation. At the end of cleavage the solid ball of cells give rise to blastula which consists of number blastomeres. The characteristic features of the blastula stage are the presence of a well defined cavity called the blastocoel. This is the beginning of the primary body cavity.