You sperm they are the male gametes of animals and are therefore responsible for sexual reproduction in these organisms. They are formed from gametogenesis, more precisely the spermatogenesis, and possess genetic information from the male individual. Sperm, like oocytes, are haploid cells, that is, they have only half the chromosome number of a species.
→ Parts of sperm
Human sperm have a basic structure: head, cervix and tail.
Head - is where the core is located. In its anterior portion is the acrosome, a cap-shaped structure originated from the Golgiense complex that releases an enzyme and covers half of the sperm head. It is the presence of these enzymes that ensures that sperm are able to enter the secondary oocyte and there is the fertilization.
Col – is the junction region between the head and tail portion;
Tail - has three distinct regions: the intermediate piece, the main piece and the end piece. The intermediate portion is where the mitochondria of this cell are located, which are responsible for carry out the process of cellular respiration and provide the energy necessary for this gamete to be able to move.
During the formation of sperm, some defects may appear, generating abnormal sperm. These sperm are seen relatively often and it is estimated that more than 10% of all sperm that are shed in an ejaculation have a problem. Among the changes observed, the presence of sperm with sizes too high or too high stand out. below average, some appear united and with two heads and there are also those with head size not normal. These sperm usually have affected motility, not being able to fertilize the oocytes.
→ Differences between oocytes and sperm
The secondary oocyte (female gamete) and sperm have several differences, such as:
The sperm is much smaller than the secondary oocyte;
The sperm is a mobile gamete due to the presence of flagella, while the secondary oocyte is immobile;
Sperm may contain either the X or Y chromosome, while the secondary egg has only the X chromosome. That is why it is said that man is responsible for sex determination in babies;
In gametogenesis, a spermatogonia gives rise to four sperm, while an ovogony gives rise to only one secondary oocyte.
Curiosity: Did you know that sperm do not survive longer than 48 hours in the female genital tract?
By Ma. Vanessa dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/biologia/o-que-e-espermatozoide.htm
