Chromosomes

Chromosomes are part of most types of cells in the body. Each chromosome has a single molecule of DNA.

Humans have 46 chromosomes (23 pairs). Half of a person's chromosomes come from the mother and half from the father. One of the 23 pairs are the sex chromosomes, X and Y. A female inherits an X chromosome from each birth parent (XX). A male inherits an X chromosome from their mother and a Y chromosome from their father (XY).

Changes in chromosomes can cause problems with how the body works. They can cause a genetic condition, such as Down syndrome.

Symptom Checker

Feeling under the weather?

Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.

Interactive Tools

Get started learning more about your health!

Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.