This process results in variation within a population because it involves the mixing of genetic information. This short video explains the role of meiotic cell division. Sexual reproduction uses the process of meiosis , which creates gametes. The process of meiosis happens in the male and female reproductive organs. As a cell divides to form gametes:. Gametes have half the total number of chromosomes that the organism needs to develop and are referred to as haploid.
For example, humans need 46 chromosomes to develop, therefore a human gamete has 23 chromosomes. Fertilisation is the fusion of the nucleus of a male gamete with the nucleus of a female gamete. This cell division process allows the gametes to have half of the genetic material of the original cell. The genetic material is packaged in structures called chromosomes and the chromosomes sorted in an orderly fashion to give each gamete the one set of genetic instructions.
Offspring made from sexual reproduction will have two sets of genetic instructions, one delivered from the male gamete pollen in plants, sperm in animals and one from the female egg.
Fig 1. Somatic cells have two of each type of chromosome, gametes have one of each. Image by P. When sperm fertilizes meets an egg, this fertilized egg is called a zygote ZYE-goat.
The zygote goes through a process of becoming an embryo and developing into a fetus. The male reproductive system and the female reproductive system both are needed for reproduction. Humans, like other organisms, pass some characteristics of themselves to the next generation.
We do this through our genes , the special carriers of human traits. The genes that parents pass along are what make their children similar to others in their family, but also what make each child unique. These genes come from the male's sperm and the female's egg. The external part of the female reproductive organs is called the vulva , which means covering.
Located between the legs, the vulva covers the opening to the vagina and other reproductive organs inside the body. The fleshy area located just above the top of the vaginal opening is called the mons pubis. Two pairs of skin flaps called the labia which means lips surround the vaginal opening. The clitoris , a small sensory organ, is located toward the front of the vulva where the folds of the labia join. Between the labia are openings to the urethra the canal that carries pee from the bladder to the outside of the body and vagina.
When girls become sexually mature, the outer labia and the mons pubis are covered by pubic hair. The vagina is a muscular, hollow tube that extends from the vaginal opening to the uterus. Because it has muscular walls, the vagina can expand and contract. This ability to become wider or narrower allows the vagina to accommodate something as slim as a tampon and as wide as a baby. The vagina's muscular walls are lined with mucous membranes, which keep it protected and moist. A very thin piece of skin-like tissue called the hymen partly covers the opening of the vagina.
Hymens are often different from female to female. Most women find their hymens have stretched or torn after their first sexual experience, and the hymen may bleed a little this usually causes little, if any, pain. Some women who have had sex don't have much of a change in their hymens, though.
And some women's hymens have already stretched even before they have sex. The vagina connects with the uterus , or womb, at the cervix which means neck. The cervix has strong, thick walls. The opening of the cervix is very small no wider than a straw , which is why a tampon can never get lost inside a girl's body.
During childbirth, the cervix can expand to allow a baby to pass. The uterus is shaped like an upside-down pear, with a thick lining and muscular walls — in fact, the uterus contains some of the strongest muscles in the female body. These muscles are able to expand and contract to accommodate a growing fetus and then help push the baby out during labor. When a woman isn't pregnant, the uterus is only about 3 inches 7. At the upper corners of the uterus, the fallopian tubes connect the uterus to the ovaries.
The ovaries are two oval-shaped organs that lie to the upper right and left of the uterus. They produce, store, and release eggs into the fallopian tubes in the process called ovulation av-yoo-LAY-shun.
There are two fallopian fuh-LO-pee-un tubes, each attached to a side of the uterus.
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