The diagram shows a portion of a plasma membrane - VCE - SSCE Biology - Question 12 - 2010 - Paper 1

Based on the diagram of the plasma membrane, Molecule X is identified as a component typically found within membrane structures. Given the options:

• A. Glycolipid: These are lipids with a carbohydrate attached, often located on the outer surface of the membrane and involved in cell recognition.
• B. Cholesterol: This molecule maintains membrane fluidity and is interspersed within the phospholipid bilayer but does not make up the main structure.
• C. Phospholipid: The primary building block of the cell membrane, forming the bilayer structure that makes up the membrane itself.
• D. Globular protein: Integral or peripheral proteins involved in various functions like transport and signaling.

Considering the structural role of Molecule X in the membrane, the correct answer is A. Glycolipid.