The following points highlight the three successive stages of oogenesis. The stages are: 1. Multiplication phase 2. Growth phase 3. Maturation phase. Oogenesis: Stage # 1. Multiplication Phase: The primordial germinal cells divide repeatedly to form the oogonia (Gr., oon = egg). The oogonia multiply by the mitotic divisions and form the primary oocytes which pass through the growth phase. [...]
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 Fertilisation in Animals:- 1. Meaning of Fertilisation 2. Process of Fertilisation 3. Kinds 4. Significance. Meaning of Fertilisation: The union of the cytoplasm and pronuclei of the male and female gametes is known as the fertilisation (L., fertilis = to bear; frevo = to bear). The fertilisation is the most commonly used method [...]