Multiple choice Endoplasmic reticulum is made of which of the following? Tubules Cisternae Vesicles 1 only 2 only 3 only 1 and 2 only 1, 2 and 3 Reveal answer Fill a bubble to check yourself E Correct answer Explanation Correct answer. Endoplasmic reticulum is made of tubules (branched network; 50-100 nm in diameter), cisternae (parallel interconnected flattened sac of 40-50 nm of thickness) and vesicles (round or oval; 25-500 nm diameter).