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3.
Hi Vivek,
Sex refers to the male and female duality of biology and reproduction, a process in biological DNA that dates back 3.5 - 4.6 billion years. Unlike organisms that only have the ability to reproduce asexually, sexed male and female pairs have the ability to produce offspring through meiosis and fertilization. The two sexes attract one another and communicate their readiness to procreate through differences in their biology.
An organism's sex category reflects its biological reproductive function rather than its sexuality other behavior. The female sex is defined as the one which produces the larger gamete and which typically bears the offspring. In contrast, the male sex has a smaller gamete and rarely bears offspring. In some animals, sex may be assigned to specific structures rather than the entire organism. Earthworms, for example, are normally hermaphrodites.