There are several kinds of human gender? Such a boring question, may be a lot of people don't want to look at.
But the fact is: this problem has always been a controversial topic in the scientific community.
From 1968 to 1999, during the international Olympic committee (ioc) collected, all involved female athletes of blood samples.
Purpose is to test whether the women athletes contains Y chromosome.
In principle, the sex chromosomes are determinants of gender, women are XX chromosome, men are XY chromosome.
In principle, the sex chromosomes are determinants of gender, women are XX chromosome, men are XY chromosome.
Since the birth was identified as female, the male Y chromosome body how? The behavior of the ioc is not reinvent the wheel?
And the result of the test report tells us: the average per 400 women athletes, there is one person contain a Y chromosome, which means this female athletes with masculine features, is not only the appearance, but also the change of the body.
The most typical example is that of the 2016 Olympics in Rio bisexual people -- -- castel caster semenya.
Caster semenya is Rio DE janeiro Olympic Games women's 800 meters champion, after inspection found that the "she" both male and female genitals, ovary and uterus.
Chromosome detection results show that the caster semenya type belongs to the x, y, is the male chromosome.
So someone called: in the women's running in the project, you will never know that ran in front of you is a man or a woman.
Chromosome that caster semenya belongs to men, why Olympic committee also put out prizes?
International Olympic committee (ioc) actually began in 1999 gave up chromosome examination, because geneticists have found that sex chromosomes have been unable to represent a person's sex.
Even if you are male chromosome x, y, is also likely to show the feminine traits; You are XX female chromosomes, are also likely to show masculine features. This kind of unique people, is the third kind of gender between the sexes, bisexual.
But strictly speaking, there are five kinds of human sex.
(male, partial male, bisexual men, women, female), it doesn't distinguish from the character, but to distinguish from the physical. Reference the chromosome, hormone levels, external genital, comprehensive conclusion.
Exist this kind of question, it is the fault of the gene of.
Under normal circumstances, a mother will leave future generations a X chromosome, father will leave future generations a X or Y chromosome.
Combination of sperm and egg, is XX or XY actually already have destiny. But not get the Y chromosome can develop into normal men.
Key determinants of biological male sex, is the SRY on the Y chromosome, it can promote the testicular development and inhibit ovarian formation.
If it is the XY chromosome and SRY gene will form in the fertilized egg after one and half months time begin to form testes.
If XX chromosome, is the direction of the X chromosome in the fertilized egg formation within 3 months after the ovaries.
The whole process, any link error, can lead to abnormal fetus gender.
Bisexual people
If belong to the x, Y chromosomes, but SRY on the Y chromosome problems, only expresses the part (promoted the testicles form, but did not inhibit ovarian formation).
The fetus may be there are both testicles and ovaries, chromosome of a check or y type, that is the bisexual men out of life.
"Partial male sex" the formation of a variety of situations, one is the XY chromosome, SRY is no exception, this kind of male hormone in the human body normal or on the high side, but show the characteristics of women, because the problem on the X chromosome.
AR gene on the X chromosome mutations, and AR gene is the key to the male hormone receptor, lack the gene, the male hormones in the body to function in the cell, men will show the feminine traits, known as "man".
Partial male type combinations alternatively XXY chromosome, is the egg in the process of the formation, meiotic abnormalities.
Men become female, male hormone secretion, female secondary sexual began to appear, such as breast development. Testicular hypoplasia normally, most people do not produce mature sperm, no fertility.
Partial female
The formation of the "partial" gender also has a variety of situations, such as the body only one X chromosome, the probability only 1 in 10000 live births in the newborn.
X to be partial to female, female characteristics, but they were all aspects of the sex hypoplasia, including ovarian and genitals, most of them can become a normal woman through medication and surgery.
Has so a news online, 19 of the three girls go to a hospital checking, unexpectedly found themselves are male, nearly 20 years to find out their gender.
Some people may feel very funny, their gender will be lost, in fact, they belonged to bisexual, it has both male and female gonads. This kind of people in the general population proportion is very low, and in modern sports is a lot see.
, as the representative of the bisexual people caster semenya let the whole world to have noticed that a small group, the international sports arbitration court for the caster semenya open the green light to allow her to take part in the women's competition, the premise is to control the levels of testosterone in the standard range.
Modern science has confirmed that there is no obvious dividing line between the sexes.
Regardless of gender, each individual should be respected, also should enjoy equal treatment.