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: Dana washes her hands a lot, so her bacteria has mutated to help to resist antibiotics. As that bacteria decreases in numbers, the mutation becomes 
 Answer: rare
Bacteria with a mutation the helps resist antibiotics increase in numbers, so the mutation becomes more common.

Question: If Earth's plate tectonics slowed down, Earth's convection would 
 Answer: decrease
Convection on early Earth was faster and so plate tectonics was faster.

Question: Tanya has a substance with mass 10kg. Logan has a substance with mass 5kg. If both substances are the same size, who has the less dense substance. 
 Answer: Logan

If we have two materials with the same volume, the material with a higher mass will be more dense.