DNA Replication Lesson for Kids

Instructor: Rebecca Gillaspy

Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.

Before your cells can divide, they need to replicate their DNA, which contains your unique genetic code. Learn how enzymes break down and build up DNA molecules during the process called DNA replication.

What Is DNA?

Did you ever notice that kids tend to look like their parents? If two redheaded parents have a child, there's a good chance their kid will also have red hair. Hair color is one of the many genetic traits that are passed down from parents to children. Your genetic traits are what make you unique, and they are kept inside a molecule called DNA, or deoxyribonucleic acid.

DNA is a double-stranded molecule that contains your unique genetic code. DNA is found in the nucleus of each of your body's cells. In fact, every cell of your body contains your entire DNA code. This explains how cops find bad guys. If a criminal leaves behind a drop of blood or a single strand of hair, cells in the blood and hair contain the criminal's complete, one-of-a-kind DNA code.

DNA Replication

Your body is constantly making new cells through cell division. Therefore, cells need a way of copying the DNA so that each new cell has the same genetic information. The process of copying a DNA molecule to produce two identical DNA molecules is called DNA replication. It has to happen before a cell can divide.

DNA replication
DNA replication

The double-strands of a DNA molecule make it resemble a ladder that's wound up like a spiral staircase. The rungs of the ladder are made up of bases that bond together in pairs. There are four bases: adenine (A), thymine (T), cytosine (C), and guanine (G). The bases are very picky about who they bond with. In fact, A will only bond with T, and C will only bond with G. We call A-T and C-G complementary pairs. As the pairs join, they make the unique rungs of the DNA ladder into a code. This code must be replicated exactly to preserve your unique traits.

How DNA Replication Works

DNA replication is controlled in a large part by enzymes. Enzymes are able to speed up reactions and either build up or break down the molecules they act on. The first enzyme involved in DNA replication is helicase. Its job is to unwind and break apart the two strands of the DNA molecule. It does this by breaking the bonds between the complementary pairs. If you picture the DNA strand as a ladder, helicase splits the ladder into two halves.

To unlock this lesson you must be a 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

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

Earning College Credit

Did you know… We have over 200 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? 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