Lesson 18 of 84 · Crosscutting Concepts
Lesson⭐ 30 XPMass Extinctions Through History
Crosscutting Concepts.
🎯 Your mission
Learn the rule. Then catch nature using it.
⚡ The twist
Nature loves to surprise the careful watcher.
Mind = Blown
🔬 The more you look, the more nature shows you.
Make a hypothesis first
Before you start: write down what you think will happen, and why.
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
- cell
Steps
Read the introduction and identify the main idea of this lesson.
Extract DNA from a strawberry using dish soap, salt, water, and rubbing alcohol. Observe the stringy white substance—that's DNA!
Look for patterns in your observations.
Make a graph or chart showing your results.
Check Your Understanding
Question 1
1 of 3What is an allele?
Where you see this in real life
This shows up in your everyday life more than you'd think.
Stretch Challenge
Try this in real life this week.
Try one experiment in real life this week — even a tiny one.
For the dinner table
“What's the most surprising thing you learned today?”
Next Smart Experiment
We'll pick an experiment that matches exactly how you're thinking right now.
Share this experiment
Send it to a parent who's looking for a 10-minute kitchen science win.
Checkout complete lesson on Crosscutting Concepts for 8th Grade
Get the full Crosscutting Concepts track as a printable PDF — all lessons, worksheets, and answer keys.