An area of land or water set aside for the protection of an ecosystem is a

Which statement is true about the cell theory? a) it is well-supported by evidence. b) it is unchangeable and permanent.

How do cells grow and reproduce to maintain homeostasis?

What is true of all organisms in the kingdoms protista, plantae, fungi, and animalia? a. they are multi-celled. b. they are photosynthetic. c. they have cells that contain membrane-bound organelles. d. they contain cells that lack membrane-bound organelles.