Distribution of visible materials in the egg and in the embryo during cleavage is, however, not always of crucial importance for the localization of parts in the developing embryo. Some substances and cellular inclusions may be displaced without disturbing the normal segregation of the embryo into its subordinate parts. This displacement can most conveniently be accomplished by centrifugation of the [...]
In this article we will discuss about:- 1. Definition of Cleavage 2. Chemical Changes during Cleavage 3. Patterns 4. Nuclei of Cleavage Cells 5. Morula and Blastula. Definition of Cleavage: One of the peculiarities of sexual reproduction in animals is that the complex multicellular body of the offspring originates from a single cell—the fertilized egg. It is necessary, therefore, that [...]
The cytoplasm of the egg, and particularly its cortex, starts the chain of reactions which eventually leads to the differentiation of parts of the embryo, it should not be assumed that the structure of the future embryo is rigidly determined by local differences in the cytoplasm of the egg. The local peculiarities of the egg cytoplasm are only some of [...]