How is the gender of the fetus determined? Or how is the gender of the fetus determined? How do fetal reproductive organs differentiate and develop? Learn about the process of fetal gender formation and how and when it is determined!
A fetus is a new life formed by the union of egg and sperm. A normal woman ovulates an egg during her menstrual cycle. The eggs have the same sex chromosomes, which are all X chromosomes. There are two types of sex chromosomes in sperm: one is sperm with X chromosome (commonly known as X chromosome sperm or X sperm); the other is sperm with Y chromosome (commonly known as Y chromosome sperm or Y sperm).
If the sperm that enters the egg is an X-chromosome sperm, and the fertilized egg formed by combining with it has XX sex chromosomes, it will be a female fetus; if the sperm that enters the egg is a Y-chromosome sperm, and the fertilized egg formed by combining with it will have XY sex chromosomes, it will form a male fetus. . Therefore, the gender of the fetus is determined entirely by male sperm.
During sexual intercourse, among the hundreds of millions of sperm ejaculated into the vagina at one time, the number of Y sperm is extremely dominant, twice that of X sperm, but in the end the number of Y sperm is almost the same or less than that of X sperm, X sperm or Y sperm Binding to the egg is completely random. It should be said that each has a 50% probability, so having a boy and giving birth to a girl are basically equal.
X sperm and Y sperm differ in appearance and performance.
X sperm is the sperm that determines the birth of a baby girl. Its characteristics are: the head of the sperm is larger, oval-shaped, and the tail is shorter, so it is larger in size and moves slower, but it has strong acid resistance and relatively strong vitality. It takes a long time and can survive in the uterine cavity or fallopian tube for 2-3 days after entering the vagina.
Y sperm is the sperm that determines the birth of a male baby. Its characteristics are: small sperm head, round and slightly pointed (pointed), long tail, fast swimming speed, weak acid resistance, easy to be frustrated, short survival time, and death soon. After entering the vagina, it only survives in the uterine cavity and fallopian tube. Can survive 24 hours
During sexual intercourse, the sperm injected into the vagina slowly advances at a speed of 30-50 microns/second and enters the cervical canal; the speed in the uterine cavity and fallopian tube is 75-100 microns/second; 12 hours after sexual intercourse, the sperm reaches the fallopian tube at most.
Only healthy and energetic sperm can make this difficult journey. In the end, only one capacitated sperm can effectively penetrate the outer membrane of the egg, enter the egg nucleus and combine with it to become a viable fertilized egg. Regardless of X sperm or Y sperm, the effective fertilization time is within 12 hours after the sperm enters the female vagina. The optimal fertilization time is 15-18 hours after the egg is discharged from the ovary.