Boy or girl has always been one of the most concern of the people, many people hope can choose according to their wish boys or girls. But boy or girl is not decided by women, this is mainly determined by the male sex chromosomes.
Sex chromosomes, just as its name implies is a decisive other chromosomes. The human reproductive cells, with 23 of the 46 chromosomes, including 22 for euchromosome, 1 on the sex chromosomes.
Female sex chromosomes for xx, genotype of 46, xx.
The male sex chromosomes for x, y, genotype for 46, XY.
Reproductive cells after two meiosis, article 23 pairs of chromosomes into 23, sex chromosome egg contains only one X, and sperm can contain X or Y chromosome, respectively. When sperm and egg, the fertilized egg's chromosomes back into 23 pairs.
If X chromosomes of sperm and egg, the fertilized egg to xx, will develop into a female fetuses.
If the Y chromosomes of sperm and egg combine, the fertilized egg is XY model, will develop into a male fetus.
Boy or girl, therefore, depends on to participate in fertilization is X sperm, or Y sperm. And the union of sperm and egg is random, it is not by the will of the people for transfer, so, boy or girl is not we can choose.
The influencing factors of baby's gender
Although we already know boy or girl principle, however, there is a situation in which always let people elusive, someone is always a boy, but someone always gave birth to a girl. Although it is not according to the wishes of the people follow one's inclinations to control the gender. However, scientists have found gender related to the following several factors:
Genetic effects. Boy or girl often has a tendency to family.
The effect of acid and alkali environment. Y sperm alkaline not acid, Y sperm in alkaline environment are active, active X sperm in acidic environment, easy to fertilization.
The influence of sex. If the woman orgasm during fertilization, easy male fetus. Because the woman orgasm secretion contains alkaline, on the contrary, if sex premature ejaculation, can increase the chances of girls.
The influence of metallic elements. Six weeks before pregnancy eat salty foods rich in potassium, sodium, and increases the chances of boys.
The influence of the season. The spring and autumn period and the conception more boys, summer conception more girls.
The effects of age. Couple each ages 5, girls the opportunity to increase 1%. Husband age is too high, having the opportunity to reduce boy and men aged between 25 and 29 male is more than a girl, is less than and greater than 25, 29, more female than male. (wen: Xu Suzhen)