The origin and development of gametes is called gametogenesis (Fig. 3(B).1). This may be divided into spermatogenesis and oogenesis. Spermatogenesis deals with the development of male sex-cells called sperms in the male gonad or testis. Oogenesis is the development of female sex-cells called ova or eggs in the female gonad or ovary. 1. Spermatogenesis: The entire process of spermatogenesis can [...]
Useful notes on Asexual Reproduction and Sexual Reproduction are described below: There is a large diversity among animals. There are about 1.2 million types of animals. The lower animals like protozoans, sponges and few coelenterates reproduce in one simple way while all the rest follow a different pattern of reproduction. Based on whether there is participation of one organism or [...]
Developmental biology or embryology is that branch of Biology which deals with the development of animals. So long as the developing animal is inside the egg, it is called as embryo. Therefore, the term Embryogenesis or Embryogeny may be defined as formation and development of embryos. It includes all the changes by which a fertilized egg is transformed into an [...]