CBSE Class 12 Biology 2025 question paper (57/2)

1. A.
   I: Pericarp, II: Endosperm, III: Scutellum
2. B.
   I: Pericarp, II: Endosperm, III: Coleorhiza
3. C.
   I: Scutellum, II: Pericarp, III: Coleorhiza
4. D.
   I: Coleorhiza, II: Scutellum, III: Pericarp

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1. A.
   44
2. B.
   22
3. C.
   23
4. D.
   46

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1. A.
   Father: $\text{I}^{\text{A}}\text{i}$, Mother: $\text{I}^{\text{B}}\text{i}$, Child: $\text{I}^{\text{A}}\text{i}$
2. B.
   Father: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Mother: $\text{I}^{\text{A}}\text{i}$, Child: $\text{I}^{\text{A}}\text{I}^{\text{A}}$
3. C.
   Father: $\text{I}^{\text{B}}\text{i}$, Mother: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Child: $\text{I}^{\text{A}}\text{i}$
4. D.
   Father: $\text{I}^{\text{B}}\text{I}^{\text{B}}$, Mother: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Child: $\text{I}^{\text{A}}\text{I}^{\text{A}}$

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1. A.
   unrelated mating
2. B.
   affected individuals
3. C.
   mating between relatives (consanguineous mating)
4. D.
   Non-identical twins

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

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1. A.
   phosphate group and OH of 3'C of a nucleoside.
2. B.
   phosphate group and OH of 5'C of a nucleoside.
3. C.
   phosphate group and H of 3'C of a nucleoside.
4. D.
   phosphate group and H of 5'C of a nucleoside.

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1. A.
   7, 7
2. B.
   8, 7
3. C.
   8, 8
4. D.
   7, 8

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

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1. A.
   Aspergillus niger
2. B.
   Lactobacillus sp.
3. C.
   Clostridium butylicum
4. D.
   Saccharomyces cerevisiae

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1. A.
   1 : 1 : 0
2. B.
   0 : 1 : 3
3. C.
   0 : 1 : 8
4. D.
   1 : 4 : 0

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1. A.
   The polymerase enzyme joins the gene of interest and the vector DNA.
2. B.
   Gel electrophoresis is used for amplification of a DNA segment.
3. C.
   PCR is used for isolation and separation of gene of interest.
4. D.
   Plasmid DNA acts as vector to transfer the piece of DNA attached to it.

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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.
   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.
   44
2. B.
   22
3. C.
   23
4. D.
   46

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1. A.
   I: Pericarp, II: Endosperm, III: Scutellum
2. B.
   I: Pericarp, II: Endosperm, III: Coleorhiza
3. C.
   I: Scutellum, II: Pericarp, III: Coleorhiza
4. D.
   I: Coleorhiza, II: Scutellum, III: Pericarp

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1. A.
   7, 7
2. B.
   8, 7
3. C.
   8, 8
4. D.
   7, 8

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1. A.
   1 : 1 : 0
2. B.
   0 : 1 : 3
3. C.
   0 : 1 : 8
4. D.
   1 : 4 : 0

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1. A.
   Father: $\text{I}^{\text{A}}\text{i}$, Mother: $\text{I}^{\text{B}}\text{i}$, Child: $\text{I}^{\text{A}}\text{i}$
2. B.
   Father: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Mother: $\text{I}^{\text{A}}\text{i}$, Child: $\text{I}^{\text{A}}\text{I}^{\text{A}}$
3. C.
   Father: $\text{I}^{\text{B}}\text{i}$, Mother: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Child: $\text{I}^{\text{A}}\text{i}$
4. D.
   Father: $\text{I}^{\text{B}}\text{I}^{\text{B}}$, Mother: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Child: $\text{I}^{\text{A}}\text{I}^{\text{A}}$

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

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

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1. A.
   unrelated mating
2. B.
   affected individuals
3. C.
   mating between relatives (consanguineous mating)
4. D.
   Non-identical twins

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1. A.
   Naturally acquired active immunity
2. B.
   Artificially acquired passive immunity
3. C.
   Naturally acquired passive immunity
4. D.
   Artificially acquired active immunity

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1. A.
   4
2. B.
   8
3. C.
   16
4. D.
   32

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1. A.
   The smaller the fragment size, the farther it moves.
2. B.
   Positively charged fragments moves to farther end.
3. C.
   The larger the fragment size, the farther it moves.
4. D.
   The negatively charged fragments do not move.

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1. A.
   Trichoderma polysporum
2. B.
   Monascus purpureus
3. C.
   Saccharomyces cerevisiae
4. D.
   Aspergillus niger

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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.
   Both Autogamy and Geitonogamy
2. B.
   Both Geitonogamy and Xenogamy
3. C.
   Geitonogamy but not Xenogamy
4. D.
   Autogamy but not Geitonogamy

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1. A.
   I: spermatozoa, II: spermatid, III: sec. spermatocyte, IV: spermatogonia
2. B.
   I: spermatid, II: spermatogonia, III: sec. spermatocyte, IV: spermatozoa
3. C.
   I: spermatogonia, II: sec. spermatocyte, III: spermatozoa, IV: spermatid
4. D.
   I: spermatogonia, II: sec. spermatocyte, III: spermatid, IV: spermatozoa

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

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1. A.
   Hargobind Khorana
2. B.
   Francis Crick
3. C.
   Watson and Crick
4. D.
   Marshall Nirenberg

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1. A.
   7, 7
2. B.
   8, 7
3. C.
   8, 8
4. D.
   7, 8

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

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

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1. A.
   Father: $\text{I}^{\text{A}}\text{i}$, Mother: $\text{I}^{\text{B}}\text{i}$, Child: $\text{I}^{\text{A}}\text{i}$
2. B.
   Father: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Mother: $\text{I}^{\text{A}}\text{i}$, Child: $\text{I}^{\text{A}}\text{I}^{\text{A}}$
3. C.
   Father: $\text{I}^{\text{B}}\text{i}$, Mother: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Child: $\text{I}^{\text{A}}\text{i}$
4. D.
   Father: $\text{I}^{\text{B}}\text{I}^{\text{B}}$, Mother: $\text{I}^{\text{A}}\text{I}^{\text{B}}$, Child: $\text{I}^{\text{A}}\text{I}^{\text{A}}$

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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.
   1 : 1 : 0
2. B.
   0 : 1 : 3
3. C.
   0 : 1 : 8
4. D.
   1 : 4 : 0

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1. A.
   The polymerase enzyme joins the gene of interest and the vector DNA.
2. B.
   Gel electrophoresis is used for amplification of a DNA segment.
3. C.
   PCR is used for isolation and separation of gene of interest.
4. D.
   Plasmid DNA acts as vector to transfer the piece of DNA attached to it.

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1. A.
   Aspergillus niger
2. B.
   Lactobacillus sp.
3. C.
   Clostridium butylicum
4. D.
   Saccharomyces cerevisiae

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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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