Like most animals, human beings produce offspring through a process known as sexual reproduction. A man and a woman have sexual intercourse to cause the woman's egg to unite with the man's sperm and make a baby.Continue Reading
Women are born with millions of very small eggs that are stored in small organs called ovaries. When a girl goes through puberty, she begins to release one of these eggs every month into the fallopian tubes that are small passageways to the uterus, where a baby grows. When boys go through puberty, they begin to produce sperm cells in their testicles. The sperm are contained in a milky white fluid known as semen.
During sexual intercourse, the man's penis is inserted into the woman's vagina. After the man has experienced sufficient stimulation, he has an orgasm, a series of muscle contractions in the penis that release semen and millions of sperm cells into the woman's vagina. They swim up the woman's vagina, past her cervix, and toward her uterus and fallopian tubes. If a single sperm cell meets with the woman's egg in the fallopian tubes or uterus, the resulting combination of the egg and the sperm becomes an organism known as a zygote.
About 14 hours after the couple has sex, the zygote may attach to the inside of the uterus, at which point the woman becomes pregnant. The zygote is then called an embryo.Learn more about Parenting