Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot.
Answer:
Choice D : Lysosome
Explanation:
In the case of damaged or unhealthy cells, lysosomes can be triggered to open up and release their digestive enzymes into the cytoplasm of the cell, killing the cell.
The answer is A.
If the bicipe muscle contracts it will bring the forearm up because the insertion of this muscle is in the forearm.
One of the functions of this muscle is flexing the elbow, which would result in the action i already mentioned.
It couldn't be B, because that would be the work of another muscle, the triceps.
