Genetics is typically a topic taught to students in middle or high school.
Well you can’t really discuss heredity and how genes are passed from parent to offspring without talking about sexual reproduction.
Children mature at different rates, and not every child is ready to learn about reproduction at the same age.That doesn’t mean that you can’t begin to introduce the topic to younger children.
Here is how I would suggest introducing genetics to kids not quite ready for “the talk”.
First, I’d try to explain what DNA is as simply as possible.
- Just like anything that needs to be assembled comes with a set of directions, EVERY LIVING THING on the planet comes with a set of directions that tell how it should be put together.
- Those directions come in the form of DNA. DNA is an abbreviation for a very long word (deoxyribonucleic acid).
- All living things have DNA. Dogs and whales have DNA. Trees and plants have DNA. Butterflies and germs have DNA. Even dinosaurs had DNA.
- Directions have to be written in a way that is easily understood. The directions that come with a toy or a kit are written using words. Well, the DNA directions that tell how to make living things are also written using words. But we call the DNA words genes.
- One piece of DNA can contain many genes. Each gene contains the instructions for making a different part of a living thing.
- human DNA contains 20,000-25,000 different genes, and every one contains the directions for making a different part of you.
- Many genes carry instructions for traits that we can observe.
There is a gene that tells what color your eyes are.
There is a gene that tells what color your hair is.
There is a gene that tells whether you are right or left handed.
There is even a gene that determines whether you think cilantro tastes like soap!
A great activity you could do at this point is to extract DNA. If you want to extract A LOT of DNA, strawberries are perfect! You can find directions for how to do that here.
But do you know what’s better than extracting strawberry DNA? Extracting YOUR OWN DNA! The process is totally painless. You can see how it’s done by watching the following video:
Genes Come in Different “Flavors”
Once kids have a basic understanding about what DNA is and how it controls the expression of traits like eye and hair color, it’s time to explain that one gene can come in more than one version.
The scientific term for the different versions of a gene is allele. With younger kids, I often refer to the different alleles as different “flavors” of a gene. I think kids can comprehend a gene coming in different flavors more easily than they can understand the abstract concept of alleles.
Try to teach this concept in a way they can understand. For instance:
Do you like milk? It’s good, right? But what about chocolate milk? I think that tastes even better!Have you ever made your own chocolate milk? You usually do that by taking plain milk and then adding chocolate powder or syrup. Once you’ve got it just the way you like it, and you take a sip, what do you taste? You taste chocolate. What color is the chocolate milk? Is it white like plain milk, or brown like the chocolate you added? I’m going to guess that your chocolate milk is brown and tastes like chocolate. What happened to the plain milk? It’s still there, right? But the chocolate flavor and color is stronger than the color and flavor of the plain milk, so you only see and taste the chocolate. We’d say the chocolate flavor was dominant over the flavor of the plain milk.
Next, explain that genes can come in different flavors too. For instance, everyone has eyes but not everyone has the same color of eyes. Some people have blue eyes, others have brown eyes, and still others have green eyes. That’s because the gene that codes for eye color comes in different flavors.
And many times, when a gene has different flavors, one flavor is stronger than another (kind of like the chocolate flavor was stronger than the plain milk flavor).
We call the stronger gene flavor the dominant flavor (or dominant allele), and the other gene flavor the recessive flavor (or recessive allele).
Next, have your kids determine which dominant genes and which recessive genes they possess by doing the following activity. This will really bring genetics to life for your kids!
It’s not only human genes that come in different flavors. The genes of dogs, cats, rabbits, plants, and just about every other living thing you can think of also come in different flavors. That’s why not every flower looks the same, nor every dog, cat, rabbit, etc.
More Ways to Explore:
In this activity, your kids can inventory what traits they have and their traits with others: Inventory of Traits.
Traits Bingo is a fun game to play with a group.
When your child is ready to understand that genes are passed down from parents to child, they can start making connections between the traits they possess and which they have in common with one or both parents.
It can be really fun when a child has a recessive trait (such as blue eyes) and his/her parents both have brown eyes. At that point, you can explain how a person has two copies of each gene. If for a given gene, a person has one dominant and one recessive allele, only expression of the dominant allele can be seen. But he or she can still pass on the recessive allele to a child. That’s what happened in our family. My husband and I are both right handed, but our son is left handed. Consequently, my husband and I must each carry a copy of the recessive left-handed allele.
In this activity, kids can explore what traits they share with family members: Family Traits Trivia.
In this activity, kids have fun “creating” their own dog by mixing different possible traits: A Recipe for Traits.
Whatever you do, have fun with it! Genetics is one of my favorite topics to teach!!
When your child is ready to learn more about how genes are expressed in cells, check out my self-paced, online course on DNA: The Alphabet of Life. They can explore how heredity works, learn how to use Punnett Squares, and understand more complicated patterns of inheritance (such as codominance, sex-linked traits, incomplete dominance, and polygenic inheritance) in my course Genetics and Heredity.
As with all of my courses, students proceed at their own pace through the material. Videos, experiments, hands-on activities, and links to additional information are included to enhance the learning experience. Periodic quizzes ensure that material is mastered before moving from one topic to the next.
If your high schooler is ready to learn more about DNA, gene expression, Mendelian (and non-Mendelian) Inheritance, Punnett Squares and more from a homeschool mom who is also a trained molecular geneticist (that’s ME!), you may be interested in my live, online high school biology class. We have a lot of fun learning all about biology with many opportunities for hands-on exploration. There is even an optional honors track available! Find out more about this course and the others I teach her: Live, Online High School Science Classes Taught by Dr. Kristin Moon