question:
Which of the following is formed immediately after fertilization?

answer:
zygote

question:
If wolves prey on deer for food, what will most likely happen to the deer population if wolves are removed from an area where deer live?

answer:
The population of deer will increase.

question:
As the human population increases, more fossil fuels are being used. The burning of fossil fuels produces greenhouse gases. How might humans reduce greenhouse gases?

answer:
Use renewable resources to generate power.

question:
Which human body system attacks viruses and bacteria once they have invaded the body?

answer:
immune