14
Lesson 14 of 84 · Spacetime
ExperimentClassifying Living Things
What You'll Learn
Living things are organized into levels: cells form tissues, tissues form organs, organs form organ systems, and organ systems make up a complete organism.
Key Words
- metamorphosis
- germination
Materials Needed
- paper towels
- markers
- tape
- small pots
- cotton balls
Safety First
- Wear safety goggles when mixing liquids.
- Wash hands after handling materials.
- Be careful with scissors — ask an adult for help if needed.
Steps
Step 1 — Read
Review the background information on Spacetime before starting.
Step 2 — Do
Compare the skeletal structures of a bird wing, human arm, and whale flipper using diagrams. Identify homologous bones and write what this tells us about common ancestry.
Step 3 — Observe
Note any unexpected results and think about why they happened.
Step 4 — Record
Share your findings with the class or a partner and discuss what you learned.
Check Your Understanding
Question 1
1 of 3What do all living things have in common?