Why is some cholesterol necessary for animal cell membranes but high cholesterol levels are dangerous?

What is turgor pressure, what causes it, and what does it do for a plant?

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

Wich level of organization includes all the other levels or organizations