Which of the following must result in a decrease in population?

Answer choices:
increased death rate and increased immigration
decreased birth rate and increased emigration
increased birth rate and increased immigration
decreased death rate and decreased emigration

Question

Which of the following must result in a decrease in population?

Answer choices:
increased death rate and increased immigration
decreased birth rate and increased emigration
increased birth rate and increased immigration
decreased death rate and decreased emigration

anonymous · Answer

@wolfe8

anonymous · Answer

Is it: increased birth rate and increased immigration?

wolfe8 · Answer

First, what is the difference between immigration and emigration?

anonymous · Answer

immigration: Movement of individuals INTO a population's area.

emigration: Movement of individuals OUT OF a population's area.

wolfe8 · Answer

Right. So let's use logic here. If you have little births, but more moving away from an area, what would happen?

anonymous · Answer

A decrease in population?

wolfe8 · Answer

Yup. But if you have a lot of births and more coming into the same place, what will happen?

anonymous · Answer

An increase in population...so the answer is:decreased birth rate and increased emigration

wolfe8 · Answer

Yup you got it. So the only things that affect an isolated population in terms of number are birth, death, immigration, and emigration. Birth and immigration add to the number, and death and emigration decreases the number.

anonymous · Answer

Ok, thanks! Do you mind checking my answers to two other questions? It's ok if you don't have the time.

wolfe8 · Answer

I can try

anonymous · Answer

Ok, thanks!

Suppose a species of beetle feeds on grass in a grassland ecosystem. Toads prey on beetles. In which of the following scenarios would a predator become a limiting factor for the beetle population?

Answer choices:
A drought reduces the toad population.
An influx of soil nutrients results in increased grass growth.
A hawk species moves in that hunts toads
The toad population increases after a warm, wet spring.

Limiting factor - Condition in an organism's environment that limits its population size.

anonymous · Answer

Would it be:A hawk species moves in that hunts toads? @wolfe8

wolfe8 · Answer

First, can you make a new post for this? For some reason I see it is how things are told to be done.

anonymous · Answer

Ok, I will make a new post.

anonymous · Answer

Ans: decreased birth rate and increased emigration