We know that all the plants and animals die after completing their life cycle. Thus, new organisms must be produced to take their place. The process of formation of new organisms of a species from pre existing ones is called reproduction. Reproduction is the most important biological activity of living organisms. It ensures the continuity of a particular species of organisms on earth by producing more and more individuals of that particular species.
Types of Reproduction
Reproduction is of two types:
1. Asexual reproduction
2. Sexual reproduction
Most of the animals and flowering plants reproduce by sexual reproduction method. In sexual reproduction a new organism is formed from two parents of different sexes (a male sex and a female sex). The male parent produces male gametes or male sex cells which are called pollens in plants and sperms in animals. The female parent produces female gametes which are called ovules or ovum in plants and eggs in animals.
The male gamete fuses with the female gamete to make a new single cell zygote. The zygote divides many times to produce a new individual. These gametes are produced by special organs present in male and female parent which are known as sex organs. In plants the male sex organ is stamen while the female sex organ is carpel. In animals the male sex organ is penis while the female sex organ is vagina. The fusion of male gamete with female gamete to produce zygote in sexual reproduction is called fertilization.