<span>Different pressure levels
Hope this helps and please award brainly :)
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Answer:
A niche is a way that a population uses the living and nonliving resources of its habitat.
Explanation:
A niche is the role a population has in it's habitat, and the second option is the best one that matches.
<span>for accurate results, for example when they are making vaccines, these are weakened harmful or disease causing viruses,, too little of the virus then it would not be a vaccine or simply would not build you antibodies, and too much of it would not also not a vaccine since it will already inflict a disease or possibly be fatal</span>
Answer: B: the variety of living things on Earth.
(Biodiversity refers to every living thing, including plants, bacteria, animals, and humans.)