All Activities
Science

Genetics: Why Do We Look Like Our Parents?

Overview

Students explore why offspring resemble their parents but are not identical, discovering the role of DNA, genes, and chromosomes in inheritance.

Learning Objective
Students understand the basic principles of inheritance and can explain how traits are passed from parents to offspring through genes.

Resources needed

  • None

Lesson stages

0 / 7 done
  1. 1 Ask: which features of your appearance do you share with your parents? Which are different?
  2. 2 Introduce: information for building your body is stored in DNA — a long molecule found in every cell nucleus.
  3. 3 DNA is organised into chromosomes — humans have 46 (23 pairs).
  4. 4 A gene is a section of DNA that codes for one trait (eye colour, blood type, etc.).
  5. 5 Introduce: you inherit one chromosome from each parent — so you get a mix of both parents genes.
  6. 6 Introduce dominant and recessive alleles: if one allele is dominant, it always shows — the recessive only shows when paired with another recessive.
  7. 7 Simple example: brown eyes (dominant) vs blue eyes (recessive) — what combinations produce each eye colour?

Tap a step to mark it as done.

Variations

  • Use a Punnett square to predict the probability of offspring traits.
  • Discuss genetic diseases: how can two healthy parents have a child with a recessive genetic disease?
  • Discuss genetic variation beyond simple dominant/recessive — most traits are influenced by many genes.
More information

Teach: DNA, gene, chromosome, inherit, allele, dominant, recessive, trait. The hierarchy is important: DNA → gene → chromosome → cell nucleus.

Focus on the DNA-gene-chromosome hierarchy before introducing dominance and recessiveness.

Can students explain what a gene is and where it is found? Can they use the concept of dominant and recessive alleles to predict the eye colour of offspring in a simple scenario?

No resources needed. The Punnett square can be drawn in soil.

Students often think offspring are a 50/50 blend of their parents — like mixing paint. Genetics involves discrete units that can be dominant or recessive, not a blending of traits.

Genetics explains inheritance, evolution, genetic diseases, and is the foundation of biotechnology.

Activity details
Secondary Challenging 25 minutes no prep Whole Class, Small Group Indoor & Outdoor
Topics
Genetics Inheritance DNA