Repnxiuction is the means by which a species is able to perpetuate itself.
If animals lived for ever, there would be no need for another generation to take over from previous ones: in reality, all animals become old or ‘worn out' and die and must be replaced if the species is not to become extinct.
All species of mammals have evolved separate sexes and reproduce sexually. This is in contrast to less highly evolved species, which may Tepnxluce asexually - producing offspring that are identical to the parent. Sexual reproduction involves the transfer of genetic material. Specialised germ cells - spermatozoa and ova - develop in the male or female animal and fuse to form a single-celled zygote. The zygote undergoes cell division to form the embryo. The offspring resulting from sexual reproduction are genetically different from each other and from their parents.
The reproductive system shares part of its structure with the urinary system and the combined systems may be referred to as the urogenital system.