Answer:
present
Explanation:
Otherwise the only similarity is that they are organelles, and can generate themselves.
The structure that serves as the cell's boundaries from its environment is known as the CELL MEMBRANE. It keeps the bad things from coming in, and releases waste out into the environment.
<span>Answer: cell membrane</span>
The answer is All of above
Answer: Possession of Valves
Explanation: Veins possess valves which ensures that blood flows in only one direction. Valves helps blood to flow back to the heart against gravitational force.
Arteries don't have valves because the pressure originating from the heart is capable of causing the blood to flow in one direction.
