Answer:
The term niche, when used in the science of ecological biology, is used to define an organism's role in an ecosystem. Not only does its niche include the environment that a given organism lives in, but it also includes the organism's "job" in that environment
Explanation:
credit to Thought.co
The answers for the question are given below
7.B
8.D
They compete for food, water and space
I think that the answer is 12 billion. So sorry if I am not right.
The blood flows through the vessels of the heart to keep it going
