Both organisms use the green parts to move. Both organisms die if the green parts are removed. The green parts in both organisms are observed making light. The green parts in both organisms can make more green parts.
I gave my students this multiple choice question: A student observes that a one-celled organism and a plant leaf have similar green parts. The student thinks that both organisms use the green parts to live. Which evidence supports the conclusion that both organisms need the green parts to live?

Only one answer is correct among these 4 choices:
- Both organisms use the green parts to move.
- Both organisms die if the green parts are removed.
- The green parts in both organisms are observed making light.
- The green parts in both organisms can make more green parts.

Could you tell me which one is correct?

Both organisms die if the green parts are removed.