All About DNA, Genes, and Chromosomes

Have you ever wondered where you got your good looks from? DNA, genes, and chromosomes are all important parts of the human body. They help make us who we are and give us certain features. Let’s break down each of these science words with simple definitions.

cell dna gene chromosome labeled diagram

What is genetics?

In simple words, genetics is the study of genes. It’s a type of science that focuses on how certain features – like the way you look or act – are passed down from ancestors and parents to children.

In a way, genetics is like a puzzle. Scientists who study genetics are called geneticists. Their job is to figure out the puzzle and discover fascinating secrets hidden in human DNA and genes.

What is DNA?

DNA double helix structure

DNA is a nickname for deoxyribonucleic acid. It’s a special molecule that contains all the information that makes you special.

Think of DNA as pages of an interesting book. And that book is all about YOU!

If you could see DNA up close with a special microscope, it would look like a twisted ladder. Scientists call this shape a “double helix.”

DNA is made up of building blocks called nucleotides. The four nucleotides have fancy names called:

  • Adenine
  • Thymine
  • Guanine
  • Cytosine

Adenine is always linked up with thymine while guanine is always linked up with cytosine. Together, these nucleotides make up the “stairs” in the twisted DNA ladder.

What are genes?

Genes are small sections of DNA – kind of like chapters in a book.

Genes are really important because they contain instructions that tell your body how to look, grow, and function.

For example, genes tell your cells how to make certain proteins. As a result, the proteins help your body work like digesting food and building muscles. Genes also determine some of your traits, like your eye color and hair texture.

What are chromosomes?

Chromosomes: Thread-like structures that contain DNA

A chromosome is like a book that holds lots of pages of DNA information. They are located in the nucleus of your cells. Up close, chromosomes look like tiny pieces of string.

Most people have 46 chromosomes, and they come in pairs. You get 23 chromosomes from your birth mother and 23 chromosomes from your birth father. This is why you might have your father’s nose and your mother’s toes.

Just as books have a spine that binds the pages together, chromosomes have special proteins called histones that hold DNA together.

Key differences between DNA, genes, and chromosomes

In summary, DNA, genes, and chromosomes are parts of the human cells. They are related to each other with a few key differences.

  • DNA are like pages of information in a recipe book.
  • Genes are like chapters of a recipe book filled with instructions.
  • Chromosomes are like recipe books that contain genes and DNA. And the recipe books are all about how to make YOU!

Learn more about the difference between DNA, genes, and chromosomes

Human Body Learning Lab anatomy book for kids

Want to learn more fun facts about your DNA, genes, and chromosomes? Human Body Learning Lab is the best anatomy book for kids.

Check out the “Building Blocks of You” chapter to learn more about cell biology and genetics.

Have fun exploring hands-on projects like how to make cells and DNA models with recycled materials!


Updated on August 28, 2023 by Betty Choi, MD

Updated on August 28, 2023

by Betty Choi, MD