This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Largest organelle in eukaryote is 
Select and explain. 
A. ER, B. Nucleus, C. Cytoskeleton, D. Golgi body
B: Nucleus
Answer: B: Nucleus 
Explanation: The Nucleus - The nucleus constitute the central, more dense, pa of the cell. It is usually rounded or ellipsoid. Occasionally it may be elongated, indented or lobed. It is the largest cell organelle measuring 4-10 um in diameter. All cells in the body contain nucleus, except mature red blood cells (RBCs) in circulation. Nuclear Components - Chromatin, Nucleolus, Nuclear membrane, Nucleoplasm. REF : Inderbir Singh's Textbook of Human Histology, seventh edition, pg.no., 28.