In frogs , micromeres and megameres are formed during

1. first cleavage b.second cleavage c.forth cleavage

In frog, the micromeres and megameres appear during third cleavage. The third occurs horizontally and is unequal i.e it occurs little above the equator toward the pole. The four cells formed during third division divide and produce eight cells. Among these eight cells, the upper four cells are smaller and are called micromeres while the lower four cells are larger with yolk and are known as macromers.