ANATOMY

Detailed explanation-1: -Cleavage in most frog and salamander embryos is radially symmetrical and holoblastic, just like echinoderm cleavage. The amphibian egg, however, contains much more yolk. This yolk, which is concentrated in the vegetal hemisphere, is an impediment to cleavage.

Detailed explanation-2: -So, the correct option is ‘Holoblastic unequal’

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: -Answer and Explanation: No, frogs do not have meroblastic cleavage. This is because the cleavage found in frogs is holoblastic and symmetrical.

Detailed explanation-5: -Humans and Marsupials are an example of unequal holoblastic cleavage. The mode of cleavage is determined by the amount of yolk and it’s distribution. The first cleavage occurs in human zygotes about 30 hours after fertilization.