Reproduction & Variation

This animated slideshow steps through the two sources of genetic variation: recombination (gene shuffling) and mutation. It will prepare them for the next activity, Make-a-Model.

Project the slide show and go through it as a class or have students explore it on their own.

• Allele shuffling (recombination) and mutation contribute to genetic variation, which underlies trait variation.
• Recombination is the random shuffling of gene variations (alleles) during sexual reproduction.
• Different versions of genes (alleles) come about through mutation—DNA copying errors during reproduction.
  • Gene differences are passed from parent to offspring during reproduction.

Some students believe children inherit different amounts of genetic information from each parent—for example, that “girls inherit more genes from their mothers.” Some may talk about inheriting traits from aunts, uncles, or other relatives that are not in their direct lineage (as parents and grandparents are).

This activity goes through mutation quickly. If you wish to spend more time on this topic, consider using the resources below.

What Is Mutation? (video) — Notice the graphic on the page, just below the video. You may want to go over it with your students.
Mutate a Gene (interactive)

Student devices with internet access, headphones

Reproduction & Variation (interactive)
Reproduction & Variation storyboard (pdf)

Have students model asexual and sexual reproduction again, using materials such as chenille stems (aka pipe cleaners) and beads.