The following points highlight the two main stages involved in the process of spermatogenesis. The stages are: 1. Formation of Spermatids 2. Spermiogenesis. Spermatogenesis: Stage # 1. Formation of Spermatids: The male germinal cells which produce the sperms are known as the primary germinal cells or primordial cells. The primordial cells pass through following three phases for the formation of [...]
The following points highlight the four main parts of mature egg of birds. The parts are: 1. Plasma Membrane 2. Primary Egg Membranes 3. Secondary Egg Membranes 4. Ooplasm. Mature Egg: Part # 1. Plasma Membrane: The mature egg is covered by a plasma membrane which is the unit membrane. It is composed of an outer and an inner layer [...]
In this article we will discuss about Parthenogenesis in Insects:- 1. Meaning of Parthenogenesis 2. Types of Parthenogenesis 3. Significance. Meaning of Parthenogenesis: Usually an un-fertilised ovum develops into a new individual only after the union with the sperm or fertilisation but in certain cases the development of the egg takes place without the fertilisation. This peculiar mode of sexual [...]