Could you be more specific? I can't really answer the question when it's written like that (no offense).
Answer:
The plasma membrane is a phospholipid
Explanation:
The plasma membrane is phospholipid bilayer. The layers are two and are continuous flat sheets. They have proteins and cholesterol embedded in them, for facilitating the transport of compounds and maintanng fluidity. The lipid bilayer is both hydrophobic and hydrophillic.
They decay. Anything that can grow will eventually start to decay over time. I hope this helps.
The answer is the occipital lobe of the brain
Eliptical (oval shaped), rather than Circular.