Based on the characteristics you describe, this is most likely a type of fungi.
Is there anything you need help with for this problem? I need to clarify first before answering your question.
Answer:
if a molecule is too large it cannot pass. also it depends on the concentration of a specific substance inside the cell. similarly, if a molecule is polar it cannot penetrate the phospholipid bilayer.
there are proteins that work as channels and pumps that allow these molecules to pass
Explanation:
The inferior vena cava brings deoxygenated blood back into the heart from the lower body. For comparison, the part that directs deoxygenated blood from the upper body is the superior vena cava.