D) The AV valves are supported by chordae tendineae so that they do not blow back up into the atria during ventricular contraction.
<span>Digestive enzymes are prolific inside the lysosomes. The organelle is named as such because these enzymes engage in "lysing" activity, meaning that the break up the worn-out cell parts or other wastes that the structure engulfs.</span>
Answer:genetic variation helps ensure that not all organisms are the same.
Explanation:
Answer:
The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place (Figure below). The transfer of oxygen into the blood is through simple diffusion. ... While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries.
Explanation: