Answer:
A forest ecosystem can support a limited number of bears because bears are the supreme predators of their ecosystem and very few animals can hunt bears so nature by supporting a limited number of bear populations supports a balanced number of population of its prey like insects, fishes, deer.
Another reason for the limited population of bear is that bear occupies the highest trophic level in the ecosystem so according to 10% law of energy transfer, it will get very less energy from its food so it needs to eat more.
Therefore the population of bears is limited because the environment can not meet the energy requirement of many bears so a forest ecosystem can support a limited number of bears.
awnser is high concentrations of oxygen
Biology helping with medical research and treatment
The human body is made up of four different types of tissues, these are epithelial, muscular, connective and nervous tissues. Epithelial tissues refers to the thin tissues, which covers all the exposed surfaces of the human body. They can be found in the following places: digestive tract, inner lining of the mouth, secretory glands, external skin, the lining of hollow part of the heart, etc. The cells of epithelial tissues are usually closely bound together and they lack blood vessels and nerves.