When does the cell have to use active transport

a) when the cell is low on energy

b) when the cell is in a highly concentrated solution

c) to move molecules across the membrane quickly

d) to move molecules across the membrane against a gradient

What role does differential reproduction play in natural selection? ! a) some organisms have different reproductive success due to nongenetic traits. b) some organisms have traits that them reach reproductive age. c) different methods of reproduction result in some organisms being genetically altered. d) reproduction varies among organisms due to pathogenic factors. the answer is not a or d based on other posts.

Afisherman is dragging his boat from the shore out into the ocean. match the following lists of areas he will move over in the correct order. continental rise continental slope continental shelf [tex]1.[/tex] [tex]2.[/tex] [tex]3.[/tex]

The transport tubes for food coming down the plants are called?