instruction:
In this task, you are given a question and answer for that. The answer will fill in the blank or will complete the unfinished question. Your task is to provide an explanation based on the given question or fill-in-the-blank statement, and answer.
question:
Question: A _____ in the population cold lead to less food availability. 
 Answer: increase
answer:
As the population increases, the food supply, or the supply of another necessary resource, may decrease.


question:
Question: If Mona shines a light through both wool and cotton and determines that cotton is more dense then wool, which material will the light move faster through? 
 Answer: wool
answer:
The more dense the medium, the slower the light moves.


question:
Question: If Mona owns a greenhouse and she decides to cover the top up to restrict sunlight, what happens to her plant's ability to make food? 
 Answer: decreases
answer:

Less photosynthesis means that plants and phytoplankton produce less food.