D) an oil spill could harm food sources for polar bears.
Answer: meiosis gamete beyond that I have no clue. complain about the lack of proper grammar to your instructor and say ou could not understand because of it
Explanation:
Answer:
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 right concentrations of ions and molecules in living cells.
Explanation: