Anatomy and Genetics: How Your DNA Shapes Your Body
Anatomy is the study of the structure and function of the human body. Genetics is the study of how traits are passed down from parents to offspring. These two fields are closely related, as our DNA shapes our bodies in many ways. Learn Anatomy
What is DNA?
DNA, or deoxyribonucleic acid, is a molecule that contains the genetic instructions for building and maintaining all living things. It is made up of four different chemical bases: adenine (A), thymine (T), guanine (G), and cytosine (C). These bases are arranged in pairs, with A always pairing with T and G always pairing with C.
What are genes?
Genes are segments of DNA that code for specific proteins. Proteins are the building blocks of our bodies and are responsible for all of our bodily functions. We have about 20,000 genes in our bodies, and each gene contains the instructions for making a different protein.
How does DNA shape our bodies?
Our DNA shapes our bodies in many ways. For example, it determines our eye color, hair color, skin color, height, weight, and even our susceptibility to certain diseases.
Here are some specific examples of how DNA shapes our bodies:
- Eye color: The color of our eyes is determined by the amount of melanin in the iris. Melanin is a pigment that gives our skin, hair, and eyes their color. People with brown eyes have more melanin in their irises than people with blue eyes.
- Hair color: Hair color is also determined by the amount of melanin in the hair shaft. People with brown hair have more melanin in their hair shafts than people with blonde hair.
- Skin color: Skin color is determined by the amount and type of melanin in the skin. People with dark skin have more melanin in their skin than people with light skin.
- Height: Height is determined by many different genes, but some of the most important genes are those that control the growth of long bones. People who have mutations in these genes may be shorter or taller than average.
- Weight: Weight is also determined by many different genes, but some of the most important genes are those that control metabolism and appetite. People who have mutations in these genes may be more likely to be overweight or obese.
- Susceptibility to disease: DNA can also influence our susceptibility to certain diseases. For example, people with certain gene mutations may be more likely to develop cancer, Alzheimer’s disease, or other chronic diseases.
How do we inherit our DNA?
We inherit our DNA from our parents. When a sperm cell fertilizes an egg cell, the two cells combine their DNA to create a new embryo. The embryo contains half of its DNA from its mother and half from its father.
Genetic inheritance patterns
There are two main patterns of genetic inheritance: dominant and recessive.
- Dominant inheritance: A dominant trait is a trait that is expressed when a person has only one copy of the gene for that trait. For example, brown eyes are a dominant trait. If a person has one gene for brown eyes and one gene for blue eyes, they will have brown eyes.
- Recessive inheritance: A recessive trait is a trait that is only expressed when a person has two copies of the gene for that trait. For example, blue eyes are a recessive trait. If a person has two genes for blue eyes, they will have blue eyes.
Genetic disorders are diseases or conditions that are caused by changes in our DNA. These changes can be inherited from our parents or they can occur spontaneously.
There are many different types of genetic disorders, including:
- Single-gene disorders: Single-gene disorders are caused by changes in one specific gene. Examples of single-gene disorders include cystic fibrosis, sickle cell anemia, and hemophilia.
- Chromosomal disorders: Chromosomal disorders are caused by changes in the structure or number of chromosomes. Examples of chromosomal disorders include Down syndrome, Klinefelter syndrome, and Turner syndrome.
- Multifactorial disorders: Multifactorial disorders are caused by a combination of genetic and environmental factors. Examples of multifactorial disorders include cancer, heart disease, and diabetes.
DNA is the blueprint for life. It shapes our bodies in many ways, from our physical appearance to our susceptibility to disease. While we cannot change our DNA, we can learn more about it and take steps to manage our health risks.
What you can do to manage your health risks
If you are concerned about your health risks, you can talk to your doctor about getting genetic testing. Genetic testing can identify changes in your DNA that may increase your risk of developing certain diseases. Once you know your genetic risks, you can take steps to manage them, such as eating a healthy diet, exercising regularly, and getting regular checkups.