Sex - Introduction, Sex Cells, Fertilization, and FAQs

Table of Contents

Introduction to Male and Female Sex Cells

In humans, sex cells are produced by the male and female reproductive systems. Male sex cells, or sperm, are produced in the testes, while female sex cells, or eggs, are produced in the ovaries.

Male sex cells are small and round, and they contain the genetic information that determines the sex of the baby. Sperm are produced in the testes, and they travel through the vas deferens to the penis. During sexual intercourse, sperm are deposited in the woman’s vagina, where they travel up the reproductive tract to the ovaries.

Female sex cells are larger and more complex than male sex cells. Eggs are produced in the ovaries, and they are released into the fallopian tubes. During sexual intercourse, sperm travel up the reproductive tract to the fallopian tubes, where they fertilize the egg. The fertilized egg then travels to the uterus, where it implants in the uterine wall and begins to grow.

Fertilization

The male sex cell, or sperm, is tiny—only about 0.05 millimeters long. It is produced in the testes, the two oval organs that lie in the scrotum, outside the body. The sperm are carried in the semen, a thick, white fluid that is ejaculated from the penis during orgasm.

The female sex cell, or ovum, is much larger—about 0.2 millimeters in diameter. It is produced in the ovaries, two almond-sized organs that lie in the pelvic cavity, just below the navel. The ovum is released from the ovary into one of the two fallopian tubes.

Fertilization is the process by which the male sperm and the female ovum unite to form a new individual. This occurs when the sperm swims up the fallopian tube to the ovum and fertilizes it. The fertilized ovum then travels down the fallopian tube to the uterus, where it implants in the uterine wall and begins to grow.

Gametes

are reproductive cells that are produced by a process called meiosis. Gametes are haploid, which means that they only have one set of chromosomes. When a gamete fuses with another gamete, the resulting cell is diploid, which means that it has two sets of chromosomes. This process is called fertilization.

Fertilization

is a process of sexual reproduction in which the male sperm cells fuse with the female egg cells to form a fertilized zygote.

The fertilized zygote divides and grows into an embryo. The embryo implants in the uterus and develops into a fetus. The fetus is born and becomes an infant.

Sex Determination in Humans

The sex of an individual is determined by the sex chromosomes. Males have one X and one Y chromosome, while females have two X chromosomes. The sex chromosomes are determined at conception.

Sex Chromosome Disorders

There are a few different sex chromosome disorders that can occur in humans. The three most common types are Turner Syndrome, Klinefelter Syndrome, and XXYY Syndrome.

Turner Syndrome is a disorder that affects females and is caused by a missing or abnormal X chromosome. Girls who have Turner Syndrome typically have short stature, webbed neck, and infertility.

Klinefelter Syndrome is a disorder that affects males and is caused by an extra X chromosome. Boys who have Klinefelter Syndrome typically have a taller than average height, enlarged breasts, and infertility.

XXYY Syndrome is a disorder that affects males and is caused by two extra X chromosomes. Boys who have XXYY Syndrome typically have a taller than average height, behavioral problems, and infertility.