Lesson: Chapter 15 — The biosphere

15.3. Pollutants and their sources 1 of 5 Reset answers

Clear all your answers?

This erases every answer in this set and starts you again at question one. Your score will be gone.

Type these four numbers to confirm:

Those numbers don't match. Look at them again and type them.

Yes, clear Keep them

Question 1

What does LD₅₀ measure?

A The dose that kills half of a pest population B How much a crop grows C The price of a pesticide D How long a chemical lasts

The right answer is the one marked above.

The dose that kills half of a pest population. A small LD₅₀ means a very poisonous chemical.

Answer the question to continue.