Asexual reproduction involves the production of offspring from only one parent. Fission is a type of asexual reproduction. The process of splitting of unicellular organisms into two or more than two separate daughter cells is called fission.

Budding is a type of asexual reproduction that may be defined as the production of a new individual from an outgrowth in the parent individual. This outgrowth develops as a protuberance, known as a bud, which later separates from the parent body and develops as an independent organism.

The time period from the fertilisation i.e. the fusion of male and female gametes to form zygote up to the parturition (birth of the baby) is called gestation. In humans, the gestation period is about forty weeks or nine months (280 days).

The age at which the sex hormones begin to be produced and the individual becomes become sexually mature to produce offspring is called puberty. This age varies from eight years to fourteen years in an average. The beginning of puberty in females is marked by the menarche and in males by the appearance of facial hair like beard and moustache.