2.The death of individuals reduces population size. If births outnumber deaths, the population grows. True
False

True

Explanation:

This would be like a birth to death ratio. If you have more deaths than births your population would decrease. See a similarity?

He is incorrect, it caused long-term changes.

Explanation:

A short term change is the one which exert a small impact over the environment which could be recover soon. Like drought, volcanic eruption, and pollution. A long term change is the one which exert a large and drastic impact over the environment which either does not recover or takes long time to recover.

The extinction of dinosaur due to asteroid strike is a long-term change because it has wiped large diversity of dinosaurs from earth. This loss was not compensated.