Find out how many chromosomes there are in a human body cell.
There are 46 chromosomes (23 pairs) in a human body cell with the exception of the sex cells. One of each pair is inherited from the mother's egg, the other from the father's sperm. When the sperm and egg unite in fertilization, they create a single cell, or zygote, with 46 chromosomes.
When cell division occurs, the 46 chromosomes are duplicated and the process is repeated billions of times over, with each of the cells containing the identical set of chromosomes. Only the gametes, or sex cells, are different. In their cell division, the members of each pair of chromosomes are separated and distributed to different cells. Each gamete has only 23 chromosomes.
Chromosomes contain thousands of genes that have information for a specific trait. That information is in the form of a chemical code, and the chemical compound that codes this genetic information is deoxyribonucleic acid or DNA.
A gene can be seen as a sequence of DNA that is coded for a specific protein. These proteins determine specific physical traits (such as height, body shape, color of hair, eyes and skin), body chemistry (blood type and metabolic functions) and some aspects of behavior and intelligence.
More than 150 human disorders are inherited and genes are thought to determine susceptibility to many diseases.