Fifth Cleavage In Frog Result In

The fifth cleavage (also double), which should provide a 32-cell embryo, is more apt to be out of line, and the symmetry and regularity of the earlier cleavages is lost. The gradient of cleavage rate from the rapidly dividing animal hemisphere blastomeres to the slowly dividing vegetal hemisphere cells now becomes more apparent.

The correct sequence in the development of frog is fertilization, cleavage, morula, blastula and gastrula. Cleavage is a term used for the early cell divisions of the zygote upto the completion of blastula stage.

The two cells of frog’s egg formed by the first cleavage represent the right and left half of the embryo. In frog, there is a regulative development. The cleavage is indeterminate. If one of the two blastomeres of frog is damaged, the development will be normal.

Cleavage is a series of rapid cell divisions without cell growth or gene expression which occurs in early embryogenesis. Early cleavage divisions in most embryos are reductive. During cleavage, the cytoplasm is divided into smaller and smaller cells, called blastomeres.