Question

which type of molecule makes up the double layer of a cell membrane? a carbohydrate b lipid c nucleic acid d protein

Explanation:

Cell membranes are composed of a phospholipid bilayer. Phospholipids are a type of lipid. Carbohydrates are often involved in cell - cell recognition on the membrane surface, nucleic acids are for genetic information storage and transfer, and proteins have various functions like transport and signaling in the membrane but do not form the bilayer structure.

Answer:

B. lipid