Genetics

There is no 'gay gene,' major study concludes

There's no such thing as a single "gay gene" that drives a person's sexual behavior, concludes the largest genetic study ever conducted on the issue.

Medical research

Sperm formation step could hold clues to male contraception

A cross-college collaboration is opening new doors in the study of male infertility by breaking down a key step in sperm formation. Isolating the intricacies of meiotic sex chromosome inactivation (MSCI), will now enable ...

Psychology & Psychiatry

First brain-wide map shows how sex and intimacy rewire the brain

How does sex relate to lasting love? To answer that question, scientists have long studied a small Midwestern rodent called the prairie vole, one of the few mammals known to form long-term, monogamous relationships.

page 1 from 40

Sex

In biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into male and female types (or sexes). Sexual reproduction involves combining specialized cells (gametes) to form offspring that inherit traits from both parents. Gametes can be identical in form and function (known as isogametes), but in many cases an asymmetry has evolved such that two sex-specific types of gametes (heterogametes) exist: male gametes are small, motile, and optimized to transport their genetic information over a distance, while female gametes are large, non-motile and contain the nutrients necessary for the early development of the young organism.

An organism's sex is defined by the gametes it produces: males produce male gametes (spermatozoa, or sperm) while females produce female gametes (ova, or egg cells); individual organisms which produce both male and female gametes are termed hermaphroditic. Frequently, physical differences are associated with the different sexes of an organism; these sexual dimorphisms can reflect the different reproductive pressures the sexes experience.

This text uses material from Wikipedia, licensed under CC BY-SA