1. PRESENTATION ON CLEAVAGE & BLASTULATION

2. Cleavage follows fertilization
Functions of cleavage
Multicellular for differentiation
The zygote is partitioned into BLASTOMERES.
Interphase is very short. It contains M&S phase
Restores Somatic nuclear to Cytoplasmic Ratio
1: _>_>_> :6
Cleavage is regular and synchronus (2n)

3. First two cleavage are vertical. The third division is horizontal
First two cleavage are vertical. The third division is horizontal . It form 8-celled vegetal & animal pole. HOLOBLASTIC cleavage . In animal with less yolk ,there is complete divison of egg is called holoblastic equal cleavage HOLOBLASTIC UNEQUAL cleavage . Where there is more yolk at vegetal pole. Cleavage is occurs more rapidly in animals Pole than in vegetal

6. A blastocel forms within the morula blastula

7. In birds the yolk is so plentiful that it restricts cleavage to the animal pole: meroblastic cleavage

10. Fate map

18. THANK YOU