reproduction

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In biology, the process by which a living organism produces other organisms more or less similar to itself. The ways in which species reproduce differ, but the two main methods are by asexual reproduction and sexual reproduction. Asexual reproduction involves only one parent without the formation of gametes: the parent's cells divide by mitosis to produce new cells with the same number and kind of chromosomes as its own. Thus offspring produced asexually are clones of the parent and there is no variation. Sexual reproduction involves two parents, one male and one female. The parents' sex cells divide by meiosis producing gametes, which contain only half the number of chromosomes of the parent cell. In this way, when two sets of chromosomes combine during fertilization, a new combination of genes is produced. Hence the new organism will differ from both parents, and variation is introduced. The ability to reproduce is considered one of the fundamental attributes of living things.

Sexual reproductive systems
The plant organs concerned with sexual reproduction are found in the flowers. These consist of the stamens (male organ) and carpels (female organ). In male mammals the reproductive system consists of the testes, which produce sperm, epididymis, sperm duct, and penis, and in the females the ovaries, which produce eggs, Fallopian tubes, and uterus.

Hermaphrodites
These are bisexual organisms, such as earthworms, that have both male and female reproductive organs, or plants whose flowers contain both stamens and carpels. This is the normal arrangement in most plants. Some plant species, such as maize and birch, which have separate male and female flowers on the same plants are described as monoeious; in dioecious species, such as willow and holly, the male and female flowers are on separate plants.