Is curettage calculated according to the last menstrual period? The correct calculation method refers to the first day of the last menstruation to 280 days after the delivery of the fetus. The normal time limit for human pregnancy is about 40 weeks. In medicine, the first day of the last menstruation is often used to calculate the expected date of delivery. The normal pregnancy time limit is about 265 days (referring to the day when the egg is fertilized), and ovulation is in the middle of menstruation, so it is 40 weeks (280 days).
If a woman's menstruation takes 28 days as a menstrual cycle, then 280 days of pregnancy is equivalent to ten months of pregnancy (28 days is a menstrual cycle) or ten menstrual cycles, so there is a saying that she is pregnant in October. The expected delivery date is only an estimate, and the actual delivery time often differs from the expected delivery date by 1-2 weeks.
The legend of boys and girls born in Qing Dynasty was invented by a scientist in China. It is based on the deduction of Yin and Yang, five elements and gossip, plus the calculation of time. At the same time, he painted a portrait of a boy and a girl, buried under an imperial tomb 700 years ago.
It is difficult to study the authenticity of the appearance of boys and girls from the Qing Dynasty, but the painting method of boys and girls is clear at a glance. According to the lunar calendar algorithm, it is clearly listed that 18 to 45-year-old women will get pregnant in different months and give birth to boys or girls. Women only need to plan monthly according to the birth of boys and girls? When you are pregnant, you can control the birth of a boy or a girl.
Is the map of Qing Palace accurate? Experts say, the so-called? Secrets of Qing Palace? At best, it can only be regarded as a statistical table, without any scientific nature.
To sum up, having boys and girls is only a matter of probability. There is no scientific basis for forecasting through the map of Qing Dynasty. From a medical point of view, only when the statistical probability is above 90% can the accuracy of the prediction be credible, while the prediction of boys and girls in "Da Qing Tu" is 50%. There are 23 pairs of 46 chromosomes in human cells. Comparing the chromosomes of men and women, it is found that 22 pairs (44 chromosomes) of men and women are the same. These identical chromosomes are called. Autologous chromosome? . The remaining pair is a very special chromosome, and the male and female chromosomes are combined in different ways. This special pair of chromosomes owned by women consists of two X chromosomes. This pair of male chromosomes consists of an X chromosome and a Y chromosome.
The size of the Y chromosome is very small, about one third of that of the X chromosome. The XY chromosome is called. Sex chromosome? . Such a small difference in chromosome combination makes us different genders. Newborns have 23 chromosomes from their mothers and 23 chromosomes from their fathers, which means that eggs and sperm provide 22 autosomes and 1 sex chromosomes respectively. Since the mother can only provide the X chromosome, the Y chromosome is obtained from the father. Therefore, it is not the mother but the father who decides the sex of the child.
The sperm produced by men is half X and half Y, which determines the sex of future children at the moment when sperm and eggs combine. Theoretically, the number of boys and girls should be 50% each, but in fact, there are about 5 1.3 boys and 48.7 girls per 100 newborn, and the ratio is roughly the same in all countries. There will always be more men than women in society. Scientists have given a very vivid explanation for this phenomenon. Y chromosome is smaller and lighter, so it? Run? It will be faster, so there is a chance to combine with the egg faster. Therefore, the combination of two X chromosomes or one X chromosome and one Y chromosome cannot be controlled artificially.
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