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 [...]
In this article we will discuss about the involvement of parental genes in the development of control of embryos. Apart from the foregoing data, which characterize the activity of the nuclear DNA in general terms, there are many indirect indications that nuclear genetic factors (the genes), after having been dormant throughout the period of cleavage, begin to manifest themselves during [...]