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:
Answer:
Which of the following is a complementary base pair ?
A . guanine - thymine
B . guanine - guanine
C . adenine - cytosine
D . guanine - cytosine
Explanation:
B.) is the answer. I think it is. I'm not completely sure. But I think this is the right answer. Can you mark me brainliest if it is please.
I don't know much but i believe the immune system which protects the body from viruses is one of those<span />
