CBSE Class 12 Biology 2023 question paper (57/5)

1. A.
   Homo habilis
2. B.
   Neanderthal man
3. C.
   Java man
4. D.
   Homo erectus

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1. A.
   (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
2. B.
   (A)-(iv), (B)-(i), (C)-(ii), (D)-(iii)
3. C.
   (A)-(iv), (B)-(iii), (C)-(i), (D)-(ii)
4. D.
   (A)-(i), (B)-(iii), (C)-(iv), (D)-(ii)

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1. A.
   Decrease in antigens
2. B.
   Decrease in antibodies
3. C.
   Increase in antibodies
4. D.
   Increase in antigens

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1. A.
   Phenylalanine, Methionine
2. B.
   Cysteine, Glycine
3. C.
   Alanine, Proline
4. D.
   Serine, Valine

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1. A.
   Commensalism
2. B.
   Parasitism
3. C.
   Amensalism
4. D.
   Mutualism

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1. A.
   Entamoeba histolytica : Constipation, abdominal pain.
2. B.
   Epidermophyton : Dry scaly lesions on nail.
3. C.
   Wuchereria bancrofti : Chronic inflammation of lymphatic vessels of lower limb.
4. D.
   Haemophilus influenzae : Blockage of the intestinal passage.

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1. A.
   $\text{gm}^{-2}\,\text{yr}^{-1}$
2. B.
   $\text{gm}^{-2}\,\text{yr}$
3. C.
   $\text{K cal m}^{-2}\,\text{yr}^{-1}$
4. D.
   $\text{K cal m}^{-2}$

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1. A.
   Left: 5' C – T – G / 3' G – A – C – G – T; Right: C – A – G 3' / C 5'
2. B.
   Left: 5' C – T / 3' G – A – G – C; Right: G – C – A – G 3' / T – C 5'
3. C.
   Left: 5' C – T – G – C / 3' G – A – C – G; Right: A – G 3' / T – C 5'
4. D.
   Left: 5' C – T – G – C – A / 3' G; Right: G 3' / A – C – G – T – C 5'

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1. A.
   330 invertebrates
2. B.
   338 invertebrates
3. C.
   359 invertebrates
4. D.
   362 invertebrates

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1. A.
   (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
2. B.
   (A)-(iii), (B)-(iv), (C)-(ii), (D)-(i)
3. C.
   (A)-(iv), (B)-(iii), (C)-(ii), (D)-(i)
4. D.
   (A)-(ii), (B)-(iv), (C)-(i), (D)-(iii)

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1. A.
   (i) only
2. B.
   (ii) only
3. C.
   (ii) and (iii)
4. D.
   (i) and (iv)

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1. A.
   X – Plumule (2n), Y – Suspensor (n), Z – Cotyledon (2n), U – Radicle (2n).
2. B.
   X – Plumule (2n), Y – Suspensor (2n), Z – Radicle (2n), U – Cotyledon (2n).
3. C.
   X – Suspensor (2n), Y – Cotyledon (2n), Z – Radicle (2n), U – Plumule (2n).
4. D.
   X – Cotyledon (2n), Y – Radicle (n), Z – Plumule (n), U – Suspensor (n).

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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1. A.
   Thymus gland
2. B.
   B-lymphocytes
3. C.
   Viral infected cells
4. D.
   Tonsils

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1. A.
   Entamoeba histolytica : Constipation, abdominal pain.
2. B.
   Epidermophyton : Dry scaly lesions on nail.
3. C.
   Wuchereria bancrofti : Chronic inflammation of lymphatic vessels of lower limb.
4. D.
   Haemophilus influenzae : Blockage of the intestinal passage.

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1. A.
   $\text{gm}^{-2}\,\text{yr}^{-1}$
2. B.
   $\text{gm}^{-2}\,\text{yr}$
3. C.
   $\text{K cal m}^{-2}\,\text{yr}^{-1}$
4. D.
   $\text{K cal m}^{-2}$

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1. A.
   X – Plumule (2n), Y – Suspensor (n), Z – Cotyledon (2n), U – Radicle (2n).
2. B.
   X – Plumule (2n), Y – Suspensor (2n), Z – Radicle (2n), U – Cotyledon (2n).
3. C.
   X – Suspensor (2n), Y – Cotyledon (2n), Z – Radicle (2n), U – Plumule (2n).
4. D.
   X – Cotyledon (2n), Y – Radicle (n), Z – Plumule (n), U – Suspensor (n).

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1. A.
   (A)-(iv), (B)-(ii), (C)-(iii), (D)-(i)
2. B.
   (A)-(ii), (B)-(i), (C)-(iv), (D)-(iii)
3. C.
   (A)-(i), (B)-(iii), (C)-(ii), (D)-(iv)
4. D.
   (A)-(ii), (B)-(i), (C)-(iii), (D)-(iv)

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1. A.
   Homo habilis
2. B.
   Neanderthal man
3. C.
   Java man
4. D.
   Homo erectus

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1. A.
   Phenylalanine, Methionine
2. B.
   Cysteine, Glycine
3. C.
   Alanine, Proline
4. D.
   Serine, Valine

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1. A.
   Amensalism
2. B.
   Parasitism
3. C.
   Mutualism
4. D.
   Commensalism

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1. A.
   (i) only
2. B.
   (ii) only
3. C.
   (ii) and (iii)
4. D.
   (i) and (iv)

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1. A.
   Gymnosperms
2. B.
   Birds
3. C.
   Amphibian
4. D.
   Mammals

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1. A.
   Left: 5' C – T – G / 3' G – A – C – G – T; Right: C – A – G 3' / C 5'
2. B.
   Left: 5' C – T / 3' G – A – G – C; Right: G – C – A – G 3' / T – C 5'
3. C.
   Left: 5' C – T – G – C / 3' G – A – C – G; Right: A – G 3' / T – C 5'
4. D.
   Left: 5' C – T – G – C – A / 3' G; Right: G 3' / A – C – G – T – C 5'

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1. A.
   (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
2. B.
   (A)-(iii), (B)-(iv), (C)-(ii), (D)-(i)
3. C.
   (A)-(iv), (B)-(iii), (C)-(ii), (D)-(i)
4. D.
   (A)-(ii), (B)-(iv), (C)-(i), (D)-(iii)

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true but, (R) is false.
4. D.
   (A) is false but, (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true but, (R) is false.
4. D.
   (A) is false but, (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true but, (R) is false.
4. D.
   (A) is false but, (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true but, (R) is false.
4. D.
   (A) is false but, (R) is true.

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1. A.
   Entamoeba histolytica : Constipation, abdominal pain.
2. B.
   Epidermophyton : Dry scaly lesions on nail.
3. C.
   Wuchereria bancrofti : Chronic inflammation of lymphatic vessels of lower limb.
4. D.
   Haemophilus influenzae : Blockage of the intestinal passage.

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1. A.
   (i) only
2. B.
   (ii) only
3. C.
   (ii) and (iii)
4. D.
   (i) and (iv)

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1. A.
   Commensalism
2. B.
   Parasitism
3. C.
   Amensalism
4. D.
   Mutualism

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1. A.
   Left: 5' C – T – G / 3' G – A – C – G – T; Right: C – A – G 3' / C 5'
2. B.
   Left: 5' C – T / 3' G – A – G – C; Right: G – C – A – G 3' / T – C 5'
3. C.
   Left: 5' C – T – G – C / 3' G – A – C – G; Right: A – G 3' / T – C 5'
4. D.
   Left: 5' C – T – G – C – A / 3' G; Right: G 3' / A – C – G – T – C 5'

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1. A.
   Phenylalanine, Methionine
2. B.
   Cysteine, Glycine
3. C.
   Alanine, Proline
4. D.
   Serine, Valine

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1. A.
   (i) and (ii)
2. B.
   (ii) and (iii)
3. C.
   (ii) and (iv)
4. D.
   (i) and (iii)

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1. A.
   (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
2. B.
   (A)-(iii), (B)-(iv), (C)-(ii), (D)-(i)
3. C.
   (A)-(iv), (B)-(iii), (C)-(ii), (D)-(i)
4. D.
   (A)-(ii), (B)-(iv), (C)-(i), (D)-(iii)

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1. A.
   Innate immunity
2. B.
   Passive immunity
3. C.
   Auto immunity
4. D.
   Active immunity

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1. A.
   $\text{gm}^{-2}\,\text{yr}^{-1}$
2. B.
   $\text{gm}^{-2}\,\text{yr}$
3. C.
   $\text{K cal m}^{-2}\,\text{yr}^{-1}$
4. D.
   $\text{K cal m}^{-2}$

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1. A.
   X – Plumule (2n), Y – Suspensor (n), Z – Cotyledon (2n), U – Radicle (2n).
2. B.
   X – Plumule (2n), Y – Suspensor (2n), Z – Radicle (2n), U – Cotyledon (2n).
3. C.
   X – Suspensor (2n), Y – Cotyledon (2n), Z – Radicle (2n), U – Plumule (2n).
4. D.
   X – Cotyledon (2n), Y – Radicle (n), Z – Plumule (n), U – Suspensor (n).

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1. A.
   10-100 times faster
2. B.
   100-1000 times faster
3. C.
   100-10000 times faster
4. D.
   1000-10000 times faster

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1. A.
   Homo habilis
2. B.
   Neanderthal man
3. C.
   Java man
4. D.
   Homo erectus

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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1. A.
   Both (A) and (R) are true and (R) is the correct explanation of (A).
2. B.
   Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. C.
   (A) is true, but (R) is false.
4. D.
   (A) is false, but (R) is true.

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