Cells use passive and active transport to move materials across cell membranes in order to maintain a constant internal environment. what is the process of maintaining a constant internal environment called?

Which statement correctly describes other ways in which nebulae and stars are different? a. a star always has a higher density than a nebula. b. stars can form inside a nebula but a nebula can never be produced by any star. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star. reset submit