Homologous Structures: Evidence for Evolution (Part 3)

What You'll Learn

Homologous structures are similar body parts in different species that suggest a common ancestor. The arm bones of humans, whales, bats, and dogs share the same basic structure.

Key Words

adaptation
fossil record
species

Materials Needed

iodine stain
paper
colored pencils
coins (for Punnett squares)

Safety First

Work in a well-ventilated area when using vinegar or other strong-smelling substances.
Dispose of materials properly after the experiment.

Steps

Step 1 — Read

Read about Cells and write down three key facts.

Step 2 — Do

Research one genetic disorder. Create an infographic showing its cause, symptoms, and how it is inherited.

Step 3 — Observe

Watch carefully for any changes and note the time.

Step 4 — Record

Create a data table to organize your measurements.

Check Your Understanding

Question 1

1 of 3

What are homologous structures?