Answer:
first and third one
Explanation:
animals need the oxygen they make. and animals eat the plants. if an animal doesnt eat plants it eats somthing that does. sorry for the typos.
Chloroplast is the cell structure that enables the process of photosynthesis
Answer:
b. to amplify the signal
Explanation:
A multi-enzyme phosphorylation cascade is a series of signaling events where one enzyme phosphorylates to another, then this last enzyme acts to phosphorylate another protein and so successively, thereby triggering a chain reaction that leads to the phosphorylation of hundreds or even thousands of proteins. A multi-enzyme phosphorylation cascade is known to increase the number of activated (phosphorylated) proteins at each step of the signaling cascade. Phosphorylation is a posttranslational modification capable of activating proteins during long periods, thereby a phosphorylation cascade also enables the activation of multiple proteins before these proteins become inactive again.