The answer is D
One way to remember this is when you are building a bridge there is one piece right in the middle that keeps the whole thing from collapsing that is called the key-stone. If a keystone species goes extinct then the rest of the ecosystem will crumble around it.
Answer:
Microorganisms are the smallest organisms on Earth. In fact, the term microorganism literally means "microscopic organism." Microorganisms may be composed of prokaryotic or eukaryotic cells,
Explanation:
Leaf area index
The leaf area index (LAI) is the ratio of total projected leaf area per unit ground area, and is widely used to characterize canopy light conditions.
is that clear
When an individual's cortisol levels are low, such as in the case of people with Addison's disease, the hypothalamus region of the brain releases corticotrophin-releasing hormones. This causes the pituitary gland to also secrete another hormone called, adenocortocotropic hormone into the bloodstream. <span>When the adrenal glands detect these hormones, they secrete cortisol, causing blood levels of cortisol to rise.</span>
