Reproduction in Animals
Reproduction is essential for the continuation of life on Earth.
There are two modes by which animals reproduce: Sexual reproduction and asexual reproduction.
Reproduction resulting from the fusion of male and female gametes is called sexual reproduction.
The reproductive organs in male include testes, sperm ducts and penis.
Testes produce the sperms.
The structure of sperm comprises: Head, middle piece and tail.
The reproductive organs in the female include ovaries, oviducts and uterus.
The ovary produces female gametes called ova or egg.
The fusion of ovum and sperm is called fertilisation.
Fertilisation is of two types: Internal fertilization and external fertilisation.
The fertilised egg is called a zygote.
The zygote divides repeatedly to form an embryo.
The embryo gets embedded in the wall of the uterus for further development.
The stage of the embryo in which all the body parts are identifiable is called foetus.
There are two types of animals based on the site of embryonic development: Viviparous animals and oviparous animals.
The transformation of the larva into adult through drastic changes is called metamorphosis.
The type of reproduction in which only a single parent is involved is called asexual reproduction.
In hydra, new individuals develop from buds by the process of budding.
Amoeba reproduces by binary fission.