Some substances can cross a cell membrane against a concentration gradient, with the help of transport proteins. Such movement from LOW to HIGH concentration is called
a. active transport
b. simple diffusion
c. facilitated diffusion
d. exocytosis
e. plasmolysis

Theories basic to all of the life sciences include the germ theory of disease. theory of evolution by natural selection. o two of these answers are correct none of these answers are correct o cell theory.

Which mechanism of transport takes place when solute particles move from a region of high concentration to a region of low concentration? active diffusion isotonic osmosis

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes