A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. Most sexual organisms have two sexes. Occasionally there are hermaphrodites in place of one or both sexes. There are also some species that are only one sex due to parthenogenesis, the act of a female reproducing without fertilization. In many cases, sex determination is genetic: males and females have different alleles or even different genes that specify their sexual morphology. In animals this is often accompanied by chromosomal differences. Determination genetically is generally through chromosome combinations of XY, ZW, XO, ZO, or haplodiploid. Sexual differentiation is generally started by a main gene, a sex locus, then a multitude of other genes follow in a domino effect. In other cases sex is determined by environmental variables (such as temperature) or social variables (the size of an organism relative to other members of its population). Environmental sex determination occurred before genetic; it is thought that a temperature-dependent amniote was the common ancestor to sex chromosomes. Some species do not have a set sex, and instead change it based on certain cues. The details of some sex-determination systems are not yet fully understood.
Sexual intercourse (or coitus or copulation) is, broadly, the insertion and thrusting of a male's penis, usually when erect, into a female's vagina for the purposes of sexual pleasure or reproduction; also known as vaginal intercourse or vaginal sex. Other forms of penetrative sexual intercourse include penetration of the anus by the penis (anal sex), penetration of the mouth by the penis or oral penetration of the vulva or vagina (oral sex), sexual penetration by the fingers (fingering), and sexual penetration by use of a strap-on dildo. These activities involve physical intimacy between two or more individuals and are usually used among humans solely for physical or emotional pleasure and commonly contribute to human bonding.
A variety of views concern what constitutes sexual intercourse or other sexual activity and their effects on health. While the term sexual intercourse, particularly the variant coitus, most commonly denotes penile-vaginal penetration and the possibility of creating offspring (the fertilization process known as reproduction), oral sex (especially when penetrative) and particularly penile-anal sex are also commonly considered sexual intercourse. Non-penetrative sex acts (such as non-penetrative forms of cunnilingus or mutual masturbation) have been termed outercourse, but may additionally be among the sexual acts contributing to human bonding and considered sexual intercourse. The term sex, often a shorthand for sexual intercourse, can mean any form of sexual activity. Because people can be at risk of contracting sexually transmitted infections during these activities, though the transmission risk is significantly reduced during non-penetrative sex, safe sex practices are advised.
In journalism, a human interest story is a feature story that discusses a person or people in an emotional way. It presents people and their problems, concerns, or achievements in a way that brings about interest, sympathy or motivation in the reader or viewer.
Human interest stories may be "the story behind the story" about an event, organization, or otherwise faceless historical happening, such as about the life of an individual soldier during wartime, an interview with a survivor of a natural disaster, a random act of kindness or profile of someone known for a career achievement.