Turn the given fact into a question by a simple rearrangement of words. This typically involves replacing some part of the given fact with a WH word. For example, replacing the subject of the provided fact with the word "what" can form a valid question. Don't be creative! You just need to rearrange the words to turn the fact into a question - easy! Don't just randomly remove a word from the given fact to form a question. Remember that your question must evaluate scientific understanding. Pick a word or a phrase in the given fact to be the correct answer, then make the rest of the question. You can also form a question without any WH words. For example, "A radio converts electricity into?"

Fact: the population divided by the area is the average number of individuals per unit of area or volume.
What is the average number of individuals per unit of area or volume?

Fact: reefs are built by organisms that usually reproduce asexually.
What are built by organisms that usually reproduce asexually?

Fact: Plant reproduction often requires gametes.

Gametes are often required for reproduction in:?