Algae grows rapidly. Mutations occur gradually in fish. Clam shells are slowly weakened. Frogs adapt quickly to new food sources.
I gave my students this multiple choice question: Nitrogen, a nutrient found in fertilizer, helps plants increase in size. Rainwater runoff often carries fertilizer into ponds and lakes. What effect does excess nitrogen have on organisms in a pond or lake ecosystem?

Only one answer is correct among these 4 choices:
- Algae grows rapidly.
- Mutations occur gradually in fish.
- Clam shells are slowly weakened.
- Frogs adapt quickly to new food sources.

Could you tell me which one is correct?

Algae grows rapidly.