Codominance: Definition & Example

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Stabilizing Selection: Examples, Definition & Graph

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:00 Definition of Codominance
  • 0:45 Examples of Codominance
  • 2:20 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Derrick Arrington

Derrick has taught biology and chemistry at both the high school and college level. He has a master's degree in science education.

There are numerous factors that play a role in determining how an organism will look and act. In this lesson, you will learn about a genetic situation known as codominance.

Definition of Codominance

We look and act the way we do because of our genes. Genes are units of hereditary information that are located on segments of chromosomes. The genes for a specific trait may exist in different forms known as alleles.

An example of an allele or a gene is a flower color. A flower may have alleles that make it red, or pink, and so on. Alleles that always show up when they are present are known as dominant alleles. Alleles that are masked or hidden by dominant alleles are known as recessive alleles. In some situations, both alleles are expressed equally. A genetic scenario where neither allele is dominant or recessive and both get expressed is known as codominance.

Examples of Codominance

Do you know your blood type? Blood types are excellent examples of codominance. A person's blood type can be A, B, AB, or O. The letters refer to the types of proteins present in the blood.

If a person has the type A protein, they have type A blood. If a person has the type B protein, they have type B blood. If a person has type O blood, then neither protein is present. If a person is type AB, then they have both A and B proteins present in their blood. If a person is type A or type B, this means that they have the dominant A or dominant B allele present in their blood. All other alleles are masked. If a person is type O, it means that neither the type A or type B allele is dominant. However, if a person is type AB, this means that both the A allele and the B allele are equally expressed and are therefore codominant.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create An Account
Support