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GATE 2022 BT Q.20: solution and answer

GATE 2022 · BTQ.20 · 1 mark · MCQ

Match the component of eukaryotic cells (Column I) with its respective function (Column II).

Column I: P. Lysosome, Q. Peroxisome, R. Glyoxysome, S. Cytoskeleton

Column II: 1. Digestion of macromolecules, 2. Detoxification of harmful compounds, 3. Conversion of fatty acids to sugar, 4. Involvement in cell motility

  1. (A)

    P-1, Q-2, R-3, S-4

  2. (B)

    P-2, Q-1, R-3, S-4

  3. (C)

    P-3, Q-1, R-2, S-4

  4. (D)

    P-4, Q-3, R-1, S-2

See the question in the paper
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Answer and solution

ANSWER

Match the component of eukaryotic cells (Column I) with its respective function (Column II). Column I: P. Lysosome, Q. Peroxisome, R. Glyoxysome, S. Cytoskeleton. Column II: 1. Digestion of macromolecules, 2. Detoxification of harmful compounds, 3. Conversion of fatty acids to sugar, 4. Involvement in cell motility

Official answer: ASource: Official answer key, GATE 2022 BT (IIT Kharagpur)

  1. Lysosome (P) contains hydrolytic (acid) enzymes such as proteases, lipases, nucleases and glycosidases that digest macromolecules delivered via endocytosis, phagocytosis and autophagy — this is its defining function, matching function 1 (Digestion of macromolecules).

  2. Peroxisome (Q) houses oxidative enzymes including catalase, which breaks down hydrogen peroxide and other reactive by-products generated during metabolic oxidation reactions — a general detoxification role present in essentially all eukaryotic cell types, matching function 2 (Detoxification of harmful compounds).

  3. Glyoxysome (R) is a specialized peroxisome-type organelle found in plant seeds and germinating tissue that carries out the glyoxylate cycle, converting stored fatty acids into sugars (succinate → gluconeogenesis precursors) to fuel seedling growth before photosynthesis starts — matching function 3 (Conversion of fatty acids to sugar).

  4. Cytoskeleton (S) is built from microtubules, microfilaments and intermediate filaments; microtubules (in cilia/flagella) and actin microfilaments (in cell crawling) directly drive cell motility — matching function 4 (Involvement in cell motility).

  5. Combining the four matches gives P-1, Q-2, R-3, S-4, which is exactly option (A).

  6. Checking the distractors confirms they are wrong: (B) swaps P and Q, wrongly giving lysosome the detoxification role; (C) wrongly assigns lysosome to fatty-acid-to-sugar conversion (the glyoxysome's unique role) and glyoxysome to digestion; (D) is a fully mismatched permutation with no correct pairing.

  7. Therefore the correct option is (A).

KEY IDEA

Each organelle listed is matched to its single best-known signature function: lysosome = intracellular digestion (hydrolytic enzymes), peroxisome = general detoxification (catalase breaking down H2O2), glyoxysome = the glyoxylate cycle converting stored fatty acids to sugars (plant seeds), cytoskeleton = structural/motility roles (microtubules, actin filaments).

WATCH OUT FOR

Confusing peroxisome's general detoxification role (H2O2 breakdown via catalase, found in nearly all cell types) with the glyoxysome's specialized fatty-acid-to-sugar conversion (glyoxylate cycle, restricted to plant seeds/germinating tissue) — swapping Q and R, or picking option (C) which assigns lysosome to the glyoxylate function instead of digestion.

From the GATE 2022 BT paper. Every question of this paper · Download the full paper · All 15 Cell biology questions, with notes

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