Cell: The Unit of Life — 30 questions with worked solutions

Free questions

30 solved MCQs, answer marked and reasoning written out

Every question below is free to read — no sign-up, no email. 2 of them are real questions from past NEET papers. The other 204 questions in this chapter are in the book and in practice access.

1. Q1 Multi-statement analysis

   Pili and fimbriae: (i) are surface structures of bacteria (ii) do not play a role in motility (iii) fimbriae help attach bacteria to rocks and host tissues (iv) they are the organs of locomotion. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.ThreeCorrect answer
   4. 4.Four

   Why option 3 is the answer

   The trap: (i)–(iii) correct; they play NO role in motility, so (iv) is wrong.

   What this is testing: whether pili and fimbriae are for grip or for movement.

   (i) is correct. Pili and fimbriae are surface structures found on many bacteria. (ii) is correct — neither one helps a bacterium move. (iii) is correct. Fimbriae are filamentous appendages that let bacteria attach to rocks, other surfaces and host tissues. (iv) is the trap. They are NOT organs of locomotion; that job belongs to the flagellum.

   So three are correct.

   The trap: fimbriae look like tiny hairs, so students assume they help the cell move like a flagellum does. Attachment and movement are different jobs, done by different structures.

   NCERT Class 11 Biology, page 91

2. Q2 Multi-statement analysis

   Inclusion bodies: (i) store reserve material in prokaryotic cells (ii) are not bound by any membrane (iii) lie free in the cytoplasm (iv) include phosphate granules and glycogen granules. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.Three
   4. 4.FourCorrect answer

   Why option 4 is the answer

   The trap: All four are correct.

   What this is testing: what inclusion bodies are and where they sit in the cell.

   All four statements are correct. Inclusion bodies store reserve material in prokaryotic cells, and unlike organelles they are NOT bound by any membrane — they lie free in the cytoplasm. Phosphate granules, cyanophycean granules and glycogen granules are the named examples.

   There is no planted error here; each line is a separate, true fact about the same structure. The exam is checking whether you remember that "unbound, free-lying storage" is the defining feature of inclusion bodies, not whether you can spot a contradiction.

   So all four are correct.

   Inclusion bodies are stores, not organelles - no membrane, lying free. That absence is what separates them from every eukaryotic counterpart.

   NCERT Class 11 Biology, page 91

3. Q3 Multi-statement analysis

   Prokaryotic cells: (i) all have a cell wall surrounding the cell membrane except mycoplasma (ii) the genetic material is naked, not enveloped by a nuclear membrane (iii) many bacteria have plasmids besides genomic DNA (iv) they possess a well-defined nucleus. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.ThreeCorrect answer
   4. 4.Four

   Why option 3 is the answer

   The trap: (i)–(iii) correct; prokaryotes have NO well-defined nucleus, so (iv) is wrong.

   What this is testing: the exception to the bacterial cell wall rule, and whether prokaryotes have a real nucleus.

   (i) is correct. Almost all prokaryotes have a cell wall around the plasma membrane, with mycoplasma as the one named exception. (ii) is correct — their genetic material is naked DNA, not wrapped in a nuclear membrane. (iii) is correct: many bacteria carry extra circular plasmid DNA besides their genomic DNA. (iv) is the trap. Prokaryotes do NOT possess a well-defined nucleus; that absence is the very feature that makes them "prokaryotic".

   So three are correct.

   The trap: (iv) directly contradicts (ii) — spotting that clash is the fastest way to the answer.

   NCERT Class 11 Biology, page 90

4. Q4 Multi-statement analysis

   Eukaryotic cells: (i) include protists, plants, animals and fungi (ii) show compartmentalisation of cytoplasm (iii) possess an organised nucleus with a nuclear envelope (iv) have genetic material organised into chromosomes. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.Three
   4. 4.FourCorrect answer

   Why option 4 is the answer

   The trap: All four are correct.

   What this is testing: the defining features shared by all eukaryotic cells.

   All four statements are correct. Eukaryotes include protists, plants, animals and fungi; their cytoplasm is compartmentalised by membranes; they possess an organised nucleus enclosed by a nuclear envelope; and their genetic material is organised into chromosomes.

   Every line names a genuine eukaryotic feature, and none is reversed or swapped with a prokaryotic trait, so there is nothing to eliminate.

   So all four are correct.

   Compartments, a true nucleus, chromosomes. Those three together are what eukaryote means.

   NCERT Class 11 Biology, page 91

5. Q5 Multi-statement analysis

   Vacuoles: (i) are bound by a single membrane called the tonoplast (ii) may occupy up to 90 per cent of the volume of a plant cell (iii) the contractile vacuole of Amoeba aids osmoregulation and excretion (iv) the tonoplast transports ions against concentration gradients into the vacuole. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.Three
   4. 4.FourCorrect answer

   Why option 4 is the answer

   The trap: All four are correct.

   What this is testing: the vacuole's membrane, its size in a plant cell, and its transport role.

   All four statements are correct. The vacuole is bound by a single membrane, the tonoplast; it can occupy up to 90 per cent of a mature plant cell's volume; Amoeba's contractile vacuole handles osmoregulation and excretion; and the tonoplast actively transports ions against their concentration gradient into the vacuole.

   Each fact stands on its own and none contradicts another, so there is no false statement to strike out.

   So all four are correct.

   Tonoplast, up to 90 per cent of the cell, and active transport across it. The vacuole concentrates solutes rather than merely holding them.

   NCERT Class 11 Biology, page 96

6. Q6 Multi-statement analysis

   The mesosome: (i) is formed by extensions of the plasma membrane into the cell (ii) occurs as vesicles, tubules and lamellae (iii) helps in cell wall formation and DNA replication (iv) contains photosynthetic pigments. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.ThreeCorrect answer
   4. 4.Four

   Why option 3 is the answer

   The trap: (i)–(iii) correct; pigment-containing membranous extensions are CHROMATOPHORES, so (iv) is wrong.

   What this is testing: what the mesosome does, and what actually carries photosynthetic pigment.

   (i) is correct. The mesosome forms from extensions of the plasma membrane into the cell interior. (ii) is correct — it appears as vesicles, tubules and lamellae. (iii) is correct: it helps in cell wall formation and DNA replication. (iv) is the trap. Photosynthetic pigments in bacteria are held in a separate membranous structure called the CHROMATOPHORE, not the mesosome.

   So three are correct.

   The trap: both mesosomes and chromatophores are plasma-membrane extensions in bacteria, which makes it easy to credit one with the other's job.

   NCERT Class 11 Biology, page 90

7. Q7 Multi-statement analysis

   Transport across the membrane: (i) passive transport needs no energy (ii) simple diffusion moves neutral solutes along the concentration gradient (iii) diffusion of water is osmosis (iv) active transport moves molecules along the concentration gradient. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.ThreeCorrect answer
   4. 4.Four

   Why option 3 is the answer

   The trap: (i)–(iii) correct; active transport moves substances AGAINST the gradient, so (iv) is wrong.

   What this is testing: how passive and active transport differ in energy and direction.

   (i) is correct. Passive transport needs no energy input. (ii) is correct — simple diffusion moves neutral solutes down (along) their concentration gradient. (iii) is correct: the diffusion of water specifically is called osmosis. (iv) is the trap. Active transport moves molecules AGAINST the concentration gradient, using energy — moving "along" the gradient is what passive transport already does.

   So three are correct.

   The trap: giving active transport the passive-transport direction erases the one feature — working against the gradient — that defines it.

   NCERT Class 11 Biology, page 94

8. Q8 Multi-statement analysis

   Cell theory as understood today states: (i) all living organisms are composed of cells and products of cells (ii) all cells arise from pre-existing cells (iii) cells may arise de novo from abiotic material (iv) the cell is the fundamental structural and functional unit of life. How many are correct?

   1. 1.One
   2. 2.Two
   3. 3.ThreeCorrect answer
   4. 4.Four

   Why option 3 is the answer

   The trap: (i),(ii),(iv) correct; cells do NOT arise de novo from abiotic material, so (iii) is wrong.

   What this is testing: the modern statement of cell theory, and whether cells can form from non-living matter.

   (i) is correct. All living organisms are made of cells and products of cells. (ii) is correct — all cells arise from pre-existing cells. (iv) is correct: the cell is the basic structural and functional unit of life. (iii) is the trap. Cells do NOT arise de novo (freshly, from scratch) from abiotic material; this directly contradicts (ii), which is the whole modern point of cell theory.

   So three are correct.

   The trap: (iii) is the old, discarded idea of spontaneous generation slipped back in — Virchow's principle in (ii) is what replaced it.

   NCERT Class 11 Biology, page 88

9. Q9 Assertion and Reason

   AssertionRough endoplasmic reticulum is abundant in cells actively engaged in protein synthesis.

   ReasonThe endoplasmic reticulum divides the intracellular space into luminal and extra-luminal compartments.

   1. 1.Both A and R are true and R is the correct explanation of A
   2. 2.Both A and R are true but R is not the correct explanation of ACorrect answer
   3. 3.A is true but R is false
   4. 4.A is false but R is true

   Why option 2 is the answer

   The trap: Both are true of the ER; the compartmentalisation of the cytoplasm is a parallel structural fact and does not explain the abundance of RER in secretory cells.

   What this is testing: whether the ER's compartmentalising role explains why RER is abundant in secretory cells.

   A says rough ER is abundant in cells actively making proteins. True — ribosomes on its surface do that synthesis. R says the ER divides the intracellular space into luminal and extra-luminal compartments. Also true, but this is a general structural fact about all ER, not a reason RER specifically piles up in protein-secreting cells.

   So both are true but R does not explain A, giving code (2).

   The trap: a true general fact about the ER is offered as if it explained a specific cell-type pattern; check that the reason actually targets the assertion's claim.

   NCERT Class 11 Biology, page 95

10. Q10 Assertion and Reason

    AssertionThe nucleolus is the site of active ribosomal RNA synthesis.

    ReasonLarger and more numerous nucleoli are present in cells actively carrying out protein synthesis.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of ACorrect answer
    3. 3.A is true but R is false
    4. 4.A is false but R is true

    Why option 2 is the answer

    The trap: Both are true of the nucleolus; the correlation with protein-synthesising cells is a parallel observation rather than the explanation of rRNA synthesis.

    What this is testing: whether nucleolus size correlating with protein synthesis explains its rRNA-making role.

    A says the nucleolus actively synthesises ribosomal RNA. True. R says larger and more numerous nucleoli occur in cells actively carrying out protein synthesis. Also true — this is a real, separately noted observation.

    R describes a pattern seen alongside A rather than explaining why the nucleolus makes rRNA in the first place, so the code is (2).

    The trap: a correlation (bigger nucleolus, more protein synthesis) is not automatically the mechanism behind rRNA synthesis itself.

    NCERT Class 11 Biology, page 100

11. Q11 Assertion and Reason

    AssertionNuclear pores permit the movement of RNA and protein molecules.

    ReasonThe nuclear pores are formed by the fusion of the two membranes of the nuclear envelope.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of ACorrect answer
    3. 3.A is true but R is false
    4. 4.A is false but R is true

    Why option 2 is the answer

    The trap: Both are true of the nuclear pores; their mode of formation is a parallel structural fact and does not explain the transport function.

    What this is testing: whether how nuclear pores form explains what they transport.

    A says nuclear pores let RNA and protein molecules move through. True. R says the pores form where the two membranes of the nuclear envelope fuse. Also true — this is how a pore is structurally built.

    R is a true fact about pore formation, but it does not by itself explain why RNA and proteins specifically pass through; it describes structure, not function. So the code is (2).

    The trap: a true structural fact and a true functional fact about the same feature can sit side by side without one causing the other.

    NCERT Class 11 Biology, page 100

12. Q12 Assertion and Reason

    AssertionThe centriole gives rise to the spindle apparatus during cell division in animal cells.

    ReasonCentrioles are made up of nine evenly spaced peripheral fibrils of tubulin protein.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of ACorrect answer
    3. 3.A is true but R is false
    4. 4.A is false but R is true

    Why option 2 is the answer

    The trap: Both are true of centrioles; the tubulin fibril composition is a parallel structural fact and does not explain the spindle-forming role.

    What this is testing: whether the centriole's tubulin fibrils explain why it forms the spindle apparatus.

    A says the centriole gives rise to the spindle apparatus during animal cell division. True. R says centrioles are made of nine evenly spaced peripheral fibrils of tubulin protein. Also true, but this is a structural fact about what centrioles are made of, not an explanation of why they specifically generate the spindle.

    Both are true but R does not explain A, so the code is (2).

    The trap: naming a structure's building material is not the same as explaining its specific biological function.

    NCERT Class 11 Biology, page 100

13. Q13 Assertion and Reason

    AssertionProkaryotic cells lack membrane-bound organelles.

    ReasonIn prokaryotic cells the genetic material is naked and is not enveloped by a nuclear membrane.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of ACorrect answer
    3. 3.A is true but R is false
    4. 4.A is false but R is true

    Why option 2 is the answer

    The trap: Both are true prokaryotic features running in parallel; the naked genetic material does not cause the absence of organelles.

    What this is testing: whether naked genetic material is what causes prokaryotes to lack membrane-bound organelles.

    A says prokaryotic cells lack membrane-bound organelles. True. R says their genetic material is naked, without a nuclear membrane. Also true, but this is a separate, parallel feature of prokaryotes — the missing nuclear envelope does not itself cause the absence of other membrane-bound organelles.

    Both are true but R does not explain A, so the code is (2).

    The trap: prokaryotes lack many things at once (nucleus, organelles), and it is tempting to chain these separate absences into one cause-and-effect story.

    NCERT Class 11 Biology, page 90

14. Q14 Assertion and Reason

    AssertionThe Golgi cisternae possess a cis face and a trans face.

    ReasonThe cis and trans faces of the Golgi are entirely different but interconnected.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of ACorrect answer
    3. 3.A is true but R is false
    4. 4.A is false but R is true

    Why option 2 is the answer

    The trap: Both are true of the Golgi; the interconnection is a parallel structural fact and does not explain the existence of the two faces.

    What this is testing: whether the Golgi's cis and trans faces being interconnected explains why it has two faces.

    A says the Golgi cisternae have a cis face and a trans face. True. R says these two faces are entirely different but interconnected. Also true as a description, but it does not explain why the Golgi is organised into these two distinct faces in the first place — it just restates that they exist and connect.

    Both are true but R does not explain A, so the code is (2).

    The trap: a true elaboration on a fact can still fail to be its explanation; check whether the reason gives a cause, not just more detail.

    NCERT Class 11 Biology, page 96

15. Q15 Assertion and Reason

    AssertionThe mesosome is a characteristic structure of prokaryotes.

    ReasonChromatophores of cyanobacteria are membranous extensions that contain pigments.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of ACorrect answer
    3. 3.A is true but R is false
    4. 4.A is false but R is true

    Why option 2 is the answer

    The trap: Both are true prokaryotic membranous structures running in parallel; the chromatophore does not explain the mesosome.

    What this is testing: whether chromatophores explain why the mesosome is a characteristic prokaryotic structure.

    A says the mesosome is a characteristic structure of prokaryotes. True. R says chromatophores of cyanobacteria are pigment-containing membranous extensions. Also true, but chromatophores are a separate structure from the mesosome — one carries pigments, the other does not — so R does not explain why the mesosome itself is characteristic of prokaryotes.

    Both are true but R does not explain A, so the code is (2).

    The trap: mesosomes and chromatophores are both plasma-membrane extensions in bacteria, but they are distinct structures with different jobs, not one explaining the other.

    NCERT Class 11 Biology, page 91

16. Q16 Assertion and Reason

    AssertionMitochondria are part of the endomembrane system.

    ReasonMitochondria, chloroplasts and peroxisomes are excluded from the endomembrane system because their functions are not coordinated with it.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of A
    3. 3.A is true but R is false
    4. 4.A is false but R is trueCorrect answer

    Why option 4 is the answer

    The trap: A is false; R is true.

    What this is testing: whether mitochondria are actually part of the endomembrane system.

    A says mitochondria are part of the endomembrane system. False — mitochondria are specifically excluded from it. R says mitochondria, chloroplasts and peroxisomes are excluded because their functions are not coordinated with the endomembrane system. True, and this correctly states the real rule.

    So A is false but R is true, giving code (4).

    The trap: mitochondria are membrane-bound like the true endomembrane organelles, which tempts students to fold them into that group — but "endomembrane" specifically means coordinated membrane traffic, which excludes mitochondria.

    NCERT Class 11 Biology, page 95

17. Q17 Assertion and Reason

    AssertionThe ribosomes of a chloroplast are 80S, larger than the cytoplasmic ribosomes.

    ReasonThe ribosomes of a chloroplast are 70S, smaller than the 80S cytoplasmic ribosomes.

    1. 1.Both A and R are true and R is the correct explanation of A
    2. 2.Both A and R are true but R is not the correct explanation of A
    3. 3.A is true but R is false
    4. 4.A is false but R is trueCorrect answer

    Why option 4 is the answer

    The trap: A is false; R is true.

    What this is testing: whether chloroplast ribosomes are 70S or 80S, and which one is actually smaller.

    A says chloroplast ribosomes are 80S, larger than cytoplasmic ribosomes. False — this reverses the real sizes. R says chloroplast ribosomes are 70S, smaller than the 80S cytoplasmic ribosomes. True, and this is the correct comparison.

    So A is false but R is true, giving code (4).

    The trap: chloroplasts (like mitochondria) carry the smaller, prokaryotic-style 70S ribosome, while the surrounding eukaryotic cytoplasm uses the larger 80S type — A simply swaps these two figures.

    NCERT Class 11 Biology, page 98

18. Q18 Statement I and Statement II

    Statement IThe vacuole is bound by a single membrane called the tonoplast.

    Statement IIIn Amoeba the contractile vacuole is important for osmoregulation and excretion.

    1. 1.Both Statement I and Statement II are correctCorrect answer
    2. 2.Both Statement I and Statement II are incorrect
    3. 3.Statement I is correct but Statement II is incorrect
    4. 4.Statement I is incorrect but Statement II is correct

    Why option 1 is the answer

    The trap: Both statements are correct.

    What this is testing: the vacuole's membrane name, and the contractile vacuole's job in Amoeba.

    Statement I says the vacuole is bound by a single membrane called the tonoplast. Correct. Statement II says in Amoeba the contractile vacuole is important for osmoregulation and excretion. Also correct.

    Both statements are correct, so the answer is (1).

    The trap: none — both facts are accurate and independent; there is nothing here to strike out.

    NCERT Class 11 Biology, page 96

19. Q19 Statement I and Statement II

    Statement IGrana are stacks of thylakoids within the chloroplast.

    Statement IIStroma lamellae are flat membranous tubules connecting the thylakoids of different grana.

    1. 1.Both Statement I and Statement II are correctCorrect answer
    2. 2.Both Statement I and Statement II are incorrect
    3. 3.Statement I is correct but Statement II is incorrect
    4. 4.Statement I is incorrect but Statement II is correct

    Why option 1 is the answer

    The trap: Both statements are correct.

    What this is testing: what grana are, and what connects grana to each other inside a chloroplast.

    Statement I says grana are stacks of thylakoids within the chloroplast. Correct. Statement II says stroma lamellae are flat membranous tubules connecting the thylakoids of different grana. Also correct.

    Both statements are correct, so the answer is (1).

    The trap: none — this pair simply confirms two connected chloroplast structures, the stacked grana and the lamellae linking them, with nothing reversed.

    NCERT Class 11 Biology, page 98

20. Q20 Statement I and Statement II

    Statement IThe telocentric chromosome has a terminal centromere.

    Statement IIThe sub-metacentric chromosome has a centromere exactly in the middle.

    1. 1.Both Statement I and Statement II are correct
    2. 2.Both Statement I and Statement II are incorrect
    3. 3.Statement I is correct but Statement II is incorrectCorrect answer
    4. 4.Statement I is incorrect but Statement II is correct

    Why option 3 is the answer

    The trap: I correct; the METACENTRIC chromosome has a middle centromere, so II is incorrect.

    What this is testing: which chromosome type has a terminal centromere, and which one has a truly central centromere.

    Statement I says the telocentric chromosome has a terminal centromere. Correct. Statement II says the sub-metacentric chromosome has a centromere exactly in the middle. Incorrect — a centromere exactly in the middle describes the METACENTRIC chromosome; sub-metacentric means the centromere sits slightly away from the middle.

    So I is correct but II is incorrect, giving answer (3).

    The trap: "sub-metacentric" sounds like a minor variant of "metacentric", but the defining feature — a truly central centromere — belongs only to metacentric, not to its "sub" version.

    NCERT Class 11 Biology, page 101

21. Q21 Match the columns

    Match the cytoskeletal/locomotory structure with its feature:

    Column I	Column II
    (a) Axoneme	(i) connects central sheath to peripheral doublets
    (b) 9+2 array	(ii) centriole-like structure
    (c) Basal body	(iii) core of cilium/flagellum
    (d) Radial spoke	(iv) nine doublets plus two central microtubules

    1. 1.(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
    2. 2.(a)-(iii), (b)-(ii), (c)-(iv), (d)-(i)
    3. 3.(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)Correct answer
    4. 4.(a)-(i), (b)-(iv), (c)-(ii), (d)-(iii)

    Why option 3 is the answer

    The trap: Axoneme-core, 9+2-nine doublets plus two central, Basal body-centriole-like, Radial spoke-connector.

    What this is testing: matching the parts of a cilium or flagellum's internal machinery to their role.

    The axoneme is the core of the cilium or flagellum; the 9+2 array means nine peripheral doublets plus two central microtubules; the basal body is a centriole-like structure at the base; and the radial spoke connects the central sheath to the peripheral doublets. That gives (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i) — option 3.

    The trap: the wrong options swap axoneme and basal body, since both are internal structural parts — but the axoneme is the shaft's core, while the basal body sits at its root and resembles a centriole.

    NCERT Class 11 Biology, page 99

22. Q22 Match the columns

    Match the organelle with its membrane character:

    Column I	Column II
    (a) Mitochondrion	(i) single membrane
    (b) Chloroplast	(iii) no membrane
    (c) Lysosome	(iv) double membrane
    (d) Ribosome	(ii) double membrane

    1. 1.(a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)
    2. 2.(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
    3. 3.(a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)Correct answer
    4. 4.(a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)

    Why option 3 is the answer

    The trap: Mitochondrion and chloroplast-double, Lysosome-single, Ribosome-none.

    What this is testing: matching four organelles to whether they have a double membrane, a single membrane, or none at all.

    Mitochondria and chloroplasts are both double membrane-bound; the lysosome has a single membrane; and the ribosome has no membrane at all. That gives (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii) — option 3.

    The trap: the wrong options try to give the lysosome a double membrane or strip mitochondria of their second membrane — keep mitochondria and chloroplasts paired as the double-membraned organelles, with lysosomes single-membraned and ribosomes membrane-free.

    NCERT Class 11 Biology, page 97

23. Q23 Match the columns

    Match the inclusion/reserve with its nature:

    Column I	Column II
    (a) Inclusion bodies	(ii) in blue-green and photosynthetic bacteria
    (b) Gas vacuoles	(iv) reserve material, not membrane bound
    (c) Plasmid	(iii) several ribosomes on one mRNA
    (d) Polysome	(i) extra-genomic circular DNA

    1. 1.(a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)
    2. 2.(a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)Correct answer
    3. 3.(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
    4. 4.(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)

    Why option 2 is the answer

    The trap: Inclusion bodies-membrane-free reserves, Gas vacuoles-photosynthetic bacteria, Plasmid-extra DNA, Polysome-ribosome chain.

    What this is testing: matching four prokaryotic cell contents to what they are and where they occur.

    Inclusion bodies are reserve material that is not membrane bound; gas vacuoles occur in blue-green and other photosynthetic bacteria; a plasmid is extra-genomic circular DNA; and a polysome is several ribosomes attached to one mRNA. That gives (a)-(iv), (b)-(ii), (c)-(i), (d)-(iii) — option 2.

    The trap: the wrong options swap inclusion bodies and plasmids, since both are non-organelle cell contents — but inclusion bodies are storage granules, while a plasmid is specifically extra DNA carrying its own genes.

    NCERT Class 11 Biology, page 91

24. Q24 Match the columns

    Match the cell/structure with its size:

    Column I	Column II
    (a) Mycoplasma	(i) 3 to 5 µm
    (b) Typical bacterium	(ii) about 7.0 µm
    (c) Human RBC	(iii) largest isolated single cell
    (d) Ostrich egg	(iv) about 0.3 µm

    1. 1.(a)-(i), (b)-(iv), (c)-(ii), (d)-(iii)
    2. 2.(a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)
    3. 3.(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)Correct answer
    4. 4.(a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)

    Why option 3 is the answer

    The trap: Mycoplasma-0.3 µm, bacterium-3 to 5 µm, RBC-7.0 µm, ostrich egg-largest.

    What this is testing: matching cells and structures to the size figures NCERT gives for each.

    Mycoplasma is about 0.3 micrometres, a typical bacterium is 3 to 5 micrometres, a human red blood cell is about 7.0 micrometres, and the ostrich egg is the largest isolated single cell. That gives (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii) — option 3.

    The trap: the wrong options shuffle these numbers between mycoplasma and bacteria, since both are microscopic — keep mycoplasma as the smallest known cell at 0.3 micrometres, distinct from the larger 3-to-5-micrometre range of ordinary bacteria.

    NCERT Class 11 Biology, page 88

25. Q25 Exception / incorrect

    All are inclusion bodies EXCEPT:

    1. 1.lysosomesCorrect answer
    2. 2.phosphate granules
    3. 3.cyanophycean granules
    4. 4.glycogen granules

    Why option 1 is the answer

    The trap: Lysosomes are membrane-bound eukaryotic organelles.

    What this is testing: which structure on the list is not actually an inclusion body.

    Phosphate granules, cyanophycean granules and glycogen granules are all inclusion bodies — unmembraned reserve material in prokaryotic cells. Lysosomes are NOT inclusion bodies; they are membrane-bound organelles found in eukaryotic cells.

    So the answer is lysosomes.

    The trap: both inclusion bodies and lysosomes can be thought of as "storage or digestive sacs" in a loose sense, but inclusion bodies are unmembraned and prokaryotic, while lysosomes are membrane-bound and eukaryotic.

    NCERT Class 11 Biology, page 91

26. Q26 Exception / incorrect

    All are types of chromosomes based on centromere position EXCEPT:

    1. 1.metacentric
    2. 2.sub-metacentric
    3. 3.polycentricCorrect answer
    4. 4.acrocentric

    Why option 3 is the answer

    The trap: The four named types are metacentric, sub-metacentric, acrocentric and telocentric.

    What this is testing: which named term is not actually one of the centromere-position-based chromosome types.

    Metacentric, sub-metacentric and acrocentric are all real chromosome types based on centromere position (along with telocentric). Polycentric is NOT one of them — it is not among the classification terms used here.

    So the answer is polycentric.

    The trap: "polycentric" sounds like it could plausibly extend the metacentric/sub-metacentric/acrocentric/telocentric series, but the classification is fixed to these four named positions only.

    NCERT Class 11 Biology, page 101

27. Q27 Sequence / ordering

    Correct order of chromosome types by decreasing arm equality:

    1. 1.metacentric → sub-metacentric → acrocentric → telocentricCorrect answer
    2. 2.telocentric → acrocentric → sub-metacentric → metacentric
    3. 3.acrocentric → metacentric → telocentric → sub-metacentric
    4. 4.sub-metacentric → telocentric → metacentric → acrocentric

    Why option 1 is the answer

    The trap: Metacentric (equal arms) → sub-metacentric → acrocentric → telocentric (terminal centromere).

    What this is testing: ordering the four chromosome types from most equal arms to least (fully terminal centromere).

    From most to least equal arms: metacentric (centromere in the middle) comes first, then sub-metacentric (slightly off-centre), then acrocentric (near one end), then telocentric (centromere at the very tip). Only option 1 gives that order.

    The trap: the other options scramble this sequence — anchor the two ends first, metacentric (perfectly equal) and telocentric (no second arm at all), and the two in-between types slot in by how far off-centre they are.

    NCERT Class 11 Biology, page 101

28. Q28 Sequence / ordering

    Correct order of levels in a eukaryotic cell:

    1. 1.organelle → molecule → cell
    2. 2.cell → organelle → molecule
    3. 3.organelle → cell → molecule
    4. 4.molecule → organelle → cellCorrect answer

    Why option 4 is the answer

    The trap: Molecules build organelles, which build the cell.

    What this is testing: the correct order of levels of organisation, from smallest to the whole cell.

    Molecules combine to build organelles, and organelles together build the cell. Only option 4 gives that order: molecule, then organelle, then cell.

    The trap: the other options start from the cell or the organelle instead of the molecule, reversing the true build-up from smallest unit to largest structure.

    NCERT Class 11 Biology, page 87

29. Q29 NEET 2023

    Which of the following are NOT considered part of the endomembrane system? A. Mitochondria B. Endoplasmic reticulum C. Chloroplasts D. Golgi complex E. Peroxisomes

    1. 1.A, C and E onlyCorrect answer
    2. 2.A and D only
    3. 3.A, D and E only
    4. 4.B and D only

    Why option 1 is the answer

    The trap: Mitochondria, chloroplasts and peroxisomes are excluded from the endomembrane system; the ER and Golgi are part of it.

    What this is testing: correctly identifying every organelle excluded from the endomembrane system, as asked in an actual NEET question.

    Mitochondria, chloroplasts and peroxisomes (A, C, E) are all excluded from the endomembrane system, because their functions are not coordinated with it. The endoplasmic reticulum and Golgi complex (B, D) ARE part of the endomembrane system, so they do not belong on this exclusion list.

    So the answer is A, C and E only.

    The trap: some distractor options wrongly include the ER or Golgi in the exclusion list — but those two, along with lysosomes and vacuoles, are the organelles that DO belong to the endomembrane system.

    NCERT Class 11 Biology, page 95

30. Q30 NEET 2021

    The organelles that are included in the endomembrane system are:

    1. 1.Endoplasmic reticulum, mitochondria, ribosomes and lysosomes
    2. 2.Endoplasmic reticulum, Golgi complex, lysosomes and vacuolesCorrect answer
    3. 3.Golgi complex, mitochondria, ribosomes and lysosomes
    4. 4.Golgi complex, endoplasmic reticulum, mitochondria and lysosomes

    Why option 2 is the answer

    The trap: The endomembrane system comprises the ER, Golgi complex, lysosomes and vacuoles; mitochondria and ribosomes are excluded.

    What this is testing: correctly naming every organelle that belongs to the endomembrane system, as asked in an actual NEET question.

    The endomembrane system is made up of the endoplasmic reticulum, Golgi complex, lysosomes and vacuoles. Mitochondria and ribosomes do NOT belong to it — mitochondria are specifically excluded, and ribosomes are non-membrane bound structures, not part of this membrane system at all.

    So the answer is option 2.

    The trap: mitochondria and ribosomes both keep showing up as distractors mixed into otherwise correct endomembrane lists, testing whether the exclusion rule is remembered consistently.

    NCERT Class 11 Biology, page 95