Consider statements about cell biology: 1. The cell membrane is made of a phospholipid bilayer. 2. Ribosomes are the site of lipid synthesis. 3. The cytoskeleton provides structural support. Which are correct? MCQ with Answer and Explanation

The cell membrane (plasma membrane) is primarily composed of a phospholipid bilayer with embedded proteins, following the fluid mosaic model. The cytoskeleton is a network of protein filaments (microtubules, microfilaments, intermediate filaments) that provides structural support, shape, and facilitates intracellular transport. Ribosomes are the site of protein synthesis, not lipid synthesis (which occurs in the smooth ER). Thus, statements 1 and 3 are correct.