Some animals can produce a potassium ion concentration inside their cells that is twenty times greater than that of their environment. This ion concentration gradient is maintained by the plasma membrane.
Identify the source of energy used to maintain the concentration gradient. Where does this energy come from?

it enhances antibody production by t cells of the adaptive immune system.

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explanation:

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.