Answer:
mitchondria is powerhouse
<span>The production of red blood cells, which transport oxygen, is triggered by a low level of oxygen in the blood. is correct.</span>
Active transport requires that the cell move engegy that it has obtained the food to move the molecule threw the cell membrane.The passive transport doesn't required as much energy for the molecule to move....
C. exocytosis (I have to use 20 characters to respond and "answer it well". Exo means out/outside and exocytosis is an active transport system where a cell uses energy to transport material, like protein or waste, from inside a cell to the outside.)