Classifying 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

plastic wrap
ruler
magnifying glass

Safety First

Do not mix unknown chemicals together.
Tie back long hair before starting the experiment.
Protect your work surface with newspaper or plastic.

Steps

Step 1 — Read

Review the background information on Equilibrium 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 3

What do all living things have in common?