Sex : Sexual dimorphism
Many species of living things are categorized into two or more forms called sexes that combine genetic material in order to reproduce. This is called sexual reproduction. Typically, a species will have two sexes: male and female (sexual dimorphism). The female is defined as the sex that produces the larger gamete. Fungi and some other organisms exist in more than two sexes, but still reproduce in pairs (any two differing sexes may reproduce). Some species, like earthworms or geckos, are capable of both sexual and asexual reproduction. Some species are hermaphrodites containing both sexes in one body.The word sex is also used to refer to sexual intercourse (the physical acts related to sexual reproduction) and other human sexual behavior, but this article will discuss the concept of sex defined above.
In mammals, birds, and many other species, sex is determined by the sex chromosomes, called X and Y in mammals, and Z and W in birds. Males typically have one of each (XY), while females typically have two X chromosomes (XX). Since all individuals have at least one X, the Y chromosome is generally reduced, and is absent in some forms, this pattern admitting some considerable variation. In other species, including crocodiles, and most insects, sex may be determined by various other sex-determination systems, including ones controlled by environmental factors like temperature, or by age.
Intersexuals are the small minority of people that were born with bodies that are difficult to assign to the traditional "male" and "female" categories because they have both genitalia, are of indeterminate sex, or combine features of both sexes. This biological fact has led some scientists to argue that sexes are cultural constructions. Some people have sought to define their sexuality and sexual identity in non-polar terms.
As part of this movement, Anne Fausto-Sterling once suggested a classification of five sexes (male, female, merm, ferm and herm). Advocates for intersexual people stated that this theory is confusing and unhelpful to the interests of intersexual people, and she has since ceased to advocate this idea.
Many social scientists use "sex" to refer to the biological division into male and female, and "gender" to refer to gender roles assigned to people on the basis of sex. There is tremendous variation of cultural attitudes, both between and within societies, to sex, sexuality, and gender roles.
See the article Pictogram for an example of a pictogram of a man and a woman, to indicate the respective toilets. It shows the man with broader shoulders and the woman in clothing that is in the western world rarely worn by men, a dress. Presumably it isn't used in countries where men wear dress-like clothing.
See also:
- autosome
- evolution
- gender and sexuality studies
- hermaphrodite
- human sexual behavior
- human sexuality
- sex organ
- sex and illness
- the assembly language mnemonic SEX
External link
- The International Encyclopedia of Sexuality (http://www2.rz.hu-berlin.de/sexology/GESUND/ARCHIV/IES/BEGIN.HTM) by Robert T. Francoeur[?] (Ed.), full text
Or dream'st thou.html">thou.html">thou.html">thou?'
He lifted his head and replied, 'even.html">Even so.'
Thereat he stood up languidly, and went to her and kissed her. And she
swiftness of limb, brightness of eye, and the longing for earthly
jewel were struggling to cast its beams through the sides of a crystal
was amazed, and cried, 'How's this? What change is passing in thee?'
She said, 'Joy in thy kiss, and that I have 'scaped Shagpat.'
Then he: 'Shagpat? How? had that wretch claim over thee ere I came?'
But she looked fearfully at the corners of the room and exclaimed, 'Hush,
power cannot keep off his emissaries at all times.' Then she said, 'O my
shall be! Wait thou for the time and it will reward thee. What! thou
under the branches, a sour tamarind? 'Tis well! I say nought, save that
thee between me and Shagpat; and that honoured one of this city thought
father, knowing me wise, and knowing the thing that transformed me to
proposal save with scorn; but the King looked favourably on it, and it is
me from Shagpat.'
Quoth Shibli Bagarag, 'A clothier, O Noorna, control the Vizier! and
against his Vizier!'--tis, wullahy! a riddle.'
She replied, ''Tis even so, eyes of mine, my betrothed! but thou know'st
three, are held in enchantment by him, and made foolish by one hair
discovery, and cried, 'The Identical!'
Then she, sighing, ''Tis that indeed! but the Identical of Identicals, the
the Genie held in bondage by me, till thou art proved by adventure, and
me as I am, and hear my story, and marvel at it; for 'tis wondrous, and a
.
On
wordlookup.net
All is still licensed under the GNU FDL.
It uses material from the wikipedia.
|
|