Question

glycoprotein: protein with carbohydrate attached
glycolipid: lipid with carbohydrate attached
peripheral membrane protein
integral membrane protein
cholesterol
channel protein
phospholipid bilayer
which structure gives the cell a boundary?
mesoderm
cell membrane
nuclear envelope

Explanation:

To determine which structure gives the cell a boundary, we analyze each option:

• Mesoderm is one of the three germ layers in embryonic development and not a cell - boundary structure.
• The cell membrane (plasma membrane) is the outermost structure of the cell (in animal cells) or lies just inside the cell wall (in plant cells). It separates the cell's internal environment from the external environment, acting as the cell's boundary.
• The nuclear envelope is a double - membrane structure that encloses the nucleus, not the entire cell.

Answer:

B. cell membrane