Answer: option D
The sodium potassium ion exchange move sodium and potassium in opposite direction in electrochemical gradients.
Explanation:
The sodium potassium pump is found in many animals plasma membranes and its moves the sodium and potassium ion in opposite direction across the plasma membrane with the hydrolysis of ATP(adenosine triphosphate) to supply the needed energy. It is an active transport process.
A situation where friction would be desirable is rubbing your hands together to make them warm in the winter time.
The answer is B between respiration and combustion
I believe the answer is "biodegradable". Hope this helps!
Because you would not want to change anything in your experiment you are just changing what you are observing
