Sexual Reproduction

Sexual reproduction is a type of reproduction that results in a growing genetic diversity of offspring. In sexual reproduction, the genes of two individuals (XX and XY) are randomly combined with each new generation. The female reproductive system and the male reproductive system are the only systems so enormously different that each sex has its different organs. All other systems have "unisex" organs

Reproduction is characterized by two processes. The first, meiosis, involves half of the 46 chromosomes. The second process, fertilization, leads to the fusion of two gametes and the restoration of the original number of chromosomes: 23 chromosomes on the paternal side and 23 on the maternal side. During meiosis, the chromosomes of each pair generally cross to obtain genetic recombination

Meiosis

It is the type of cell division that allows for sexual reproduction since it reduces the number of chromosomes of the species in half, which makes it possible to combine two gametes to form a new individual with the same number of chromosomes of each parent

Although the timing of meiosis is different in women and men, the basic chromosomal dynamics of the processes are the same in both sexes, most human cells contain 46 chromosomes, each chromosome contains several 100 genes (~ 500-600 genes / chromosome), these genes are the instructions to be transmitted to new cells, most of the cells of the body are produced by mitosis: a type of cell division that produces genetically identical copies, each cell in your body has all the genes For all instructions that a human needs, egg and sperm formation requires a different type of cell division

Meiosis: each cell has 46 chromosomes, but in the form of pairs . We have two of each type of chromosome or 23 pairs of chromosomes (1 for each mum pair; 1 for dad, egg and sperm formation requires sex cells that only have one set of chromosomes). Meiosis occurs during spermatogenesis and oogenesis, when the sperm cell fertilizes the egg So the fertilized egg has 46 chromosomes again (meiosis forms sex cells (eggs and sperm))

• In mitosis, the chromosomes replicate during the interface and the cells divide (PMAT) once to produce 2 identical cells, each with 46 (23 pairs) of chromosomes

• In meiosis, chromosomes replicate during the interface as in mitosis, but then go through two sets of cell divisions (PMAT) → (PMAT) to produce a total of 4 unique cells, each with 23 chromosomes

Sex detarmination  

There is a specific type of chromosome which are known as sex chromosomes. In humans, the mother's egg contains an X chromosome. The sperm of the father contains an X or Y chromosome. A child will inherit a pair of sex chromosomes, or an X from the mother and an X from the father OR an X from the mother and a Y from the father. This random inheritance will determine whether the boy is a boy or a girl. It is important to note that the sex chromosome that a child inherits from his father will determine his sex

Fertilization

                             (The Fusion of sexual cells)

In order for fertilization to occur, that is, for a sperm to join an egg, the man must ejaculate in the woman's vagina. This expulsion occurs during sex, when the man experiences intense pleasure called orgasm. However, ejaculation does not necessarily lead to fertilization, as the fertility period is limited to a few days per ovarian cycle. If the egg is not fertilized during this short period, it degenerates and is eliminated with menstrual flow

Sexual relationship

Various types of sensory or psychic stimuli can cause sexual arousal. In men, this stimulation causes an erection of the penis, while the woman's vagina secretes lubricating mucus. Each of clitoris, labia majora and nipples are also erect. The sexual relationship itself (or sexual intercourse) begins when the man introduces his penis into the woman's vagina. Both partners experience a greater sense of pleasure

When man's pleasure reaches its paroxysm, muscle spasms works to excrete sperm contained in his urethra, what is known as ejaculation occurs. The woman may also feel an orgasm, but is not accompanied by ejaculation. However, the contraction of the muscle walls of the vagina can cause partner orgasm. During an ejaculation, 300 to 500 million sperm are deposited on the bottom of the vagina. Thanks to the waves of his flagellum, the sperm migrates to the uterus and rises into the fallopian tubes, where one of them can fertilize an egg