A  A  A   Print
GeneticsGenética

Genetics

What is genetics?

Picture of a model of a strand of DNA, magnified

Genetics is the study of the patterns of inheritance--how traits and characteristics are passed from parents to their children. Genes are formed from segments of DNA (deoxyribonucleic acid), the molecule that encodes genetic information in the cells. DNA controls the structure, function, and behavior of cells and can create exact copies of itself.

Humans have an estimated 25,000 different genes that contain specific genetic information. These genes are located on chromosomes (stick-like structures in the nucleus of cells). Every cell contains 46 chromosomes grouped in 23 pairs. The gamete (egg or sperm) from each parent only contains one half of each chromosome pair. When the two gametes unite and the egg is fertilized, the single chromosomes from each parent join again to form new pairs. The baby's gender is determined by one of the chromosome pairs: females have two X chromosomes and males have one X and one Y chromosome.

Genetic illustration, chromosome
Click Image to Enlarge

Genes are lined up on the chromosomes in specific positions and locations. Although these locations are the same for each pair of chromosomes, the genes may be similar or different. Just as traits, such as blue eyes and curly hair, are passed from the genetic information of the parents to a baby, inherited diseases and abnormalities can also be passed on. Some disorders are recessive, meaning that the abnormal gene must be received from both parents. Other disorders are dominant, meaning an abnormal gene may come from only one parent for the disorder to occur.

When a gene is abnormal, or when entire chromosomes are missing or duplicated, defects in the structure or function of the body's organs or systems can occur. These mutations or abnormalities can result in disorders, such as cystic fibrosis, a recessive genetic disease, or Down syndrome, a condition that occurs when a baby receives three copies of the #21 chromosome.

 
Today's Interactive Tools

The third-party content provided in the Health Library of phoebeputney.com is for informational purposes only and is not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your physician. If you or your child has or suspect you may have a health problem, please consult your primary care physician. If you or your child may have a medical emergency, call your doctor or 911 or other emergency health care provider immediately in the United States or the appropriate health agency of your country. For more information regarding site usage, please visit: Privacy Information, Terms of Use or Disclaimer.

Follow us online:

© 2014 Phoebe Putney Health System  |  417 Third Avenue, Albany, Georgia 31701  |  Telephone 877.312.1167

Phoebe Putney Health System is a network of hospitals, family medicine clinics, rehab facilities, auxiliary services, and medical education training facilities. Founded in 1911,
Phoebe Putney Memorial Hospital (the flagship hospital) is one of Georgia's largest comprehensive regional medical centers. From the beginning, Phoebe's mission and vision
has been to bring the finest medical talent and technology to the citizens of Southwest Georgia, and to serve all citizens of the community regardless of ability to pay.