Mass Extinctions Through History (Part 3)

What You'll Learn

Extinction occurs when the last member of a species dies. Mass extinctions have occurred several times in Earth's history, the most famous killing the dinosaurs 66 million years ago.

Key Words

heredity
allele

Materials Needed

tape
index cards
markers
ruler
scissors
microscope (or magnifying glass)

Safety First

Handle glass items carefully to avoid breakage.
Do not mix unknown chemicals together.
Tie back long hair before starting the experiment.

Steps

Step 1 — Read

Read and learn: Extinction occurs when the last member of a species dies. Mass extinctions have occurred several times in Earth's history, the most famous killing the dinosaurs 66 million years ago.

Step 2 — Do

Follow the procedure carefully, step by step.

Step 3 — Observe

Look for patterns in your observations.

Step 4 — Record

Make a graph or chart showing your results.

Check Your Understanding

Question 1

1 of 3

What is an allele?