Centrosome and Cell Division — NEET Biology

Correct answer: C — S1, S4 and S5

The core concept tested is the structure, membrane status, distribution, and functional characteristics of various eukaryotic cell organelles, as described in NCERT. S1: Ribosomes are indeed non-membrane bound organelles found freely in the cytoplasm, and also within certain organelles like chloroplasts (in plants) and mitochondria. This statement is correct. (NCERT Page 88). S2: Centrosomes are non-membrane bound organelles, but they are found primarily in *animal cells* and are absent in almost all plant cells. Therefore, this statement is NOT correct. (NCERT Page 88, Page 91). S3: The endomembrane system includes the endoplasmic reticulum, Golgi complex, lysosomes, and vacuoles. However, mitochondria are *not* considered part of the endomembrane system because their functions are not coordinated with the other components. Therefore, this statement is NOT correct. (NCERT Page 95). S4: Plant cells are distinct from animal cells because they typically possess cell walls, plastids (like chloroplasts), and a large central vacuole, all of which are generally absent in animal cells. This statement is correct. (NCERT Page 91). S5: Eukaryotic ribosomes are 80S, comprising 60S and 40S subunits, and prokaryotic ribosomes are 70S, comprising 50S and 30S subunits. This statement accurately describes the types and subunits of ribosomes. This statement is correct. (NCERT Page 98). Statements S1, S4 and S5 are correct. Final Answer: The final answer is C because statements S1, S4 and S5 are correct.