Answer:
Active transport: movement against a gradient To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the proper concentrations of ions and molecules in living cells.
Answer:
They enable protein production.
Explanation:
True because excretory is like sweat and you sweat through your skin- more specifically the pores in your skin
The dorsal side of the frog is the back of the frog, where the spine is.
The fact that gravity exists as it can be repeatedly tested and verified
