Evolution: Theories of origin of life and evidence of evolution
The origin of life on Earth and evolution are closely connected, as one explains how life began and the other explains how it changed over […]
Developmental biology
Meiotic cell division (Meiosis), its stages and significance
What is meiosis? The term meiosis is derived from the Greek word ‘meioum’ which means to reduce. It is a special kind of cell division, […]
Mitotic cell division (Mitosis), its stages and Significance
What is cell division? Life of multicellular organisms starts from a single cell known as a zygote. An adult plant or animal contains millions of […]
Sequential events and stages in the development of frog (pre-embryonic, embryonic and post-embryonic development)
Introduction: In sexual reproduction, development of organisms begins with a fertilized egg or zygote. Zygote divides and re-divides to form an embryo. Embryo is the […]
Formation and development of male and female gametophytes in angiosperms
A gametophyte is the haploid phase in the life cycle of a plant that produces gametes. The process of formation of gametes or germ cells […]
The process of fertilization and development of embryo in angiosperms
The fusion of male gamete and female gamete in sexual reproduction is called fertilization. In angiosperms, the female gamete lies deep in the ovarian cavity, […]