CBSE Class 12 Biology 2024 question paper (57/3)

1. A.
   embryo sac
2. B.
   nucellus
3. C.
   integuments
4. D.
   megaspore

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1. A.
   280
2. B.
   860
3. C.
   1720
4. D.
   1860

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1. A.
   more in number
2. B.
   less in number
3. C.
   both were equal in number
4. D.
   both were less in number

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1. A.
   Black pepper
2. B.
   Mustard
3. C.
   Groundnut
4. D.
   Citrus

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1. A.
   50% Red : 50% White
2. B.
   25% Red : 50% Pink : 25% White
3. C.
   50% Pink : 50% White
4. D.
   25% Pink : 50% Red : 25% White

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1. A.
   Klinefelter's syndrome
2. B.
   Down's syndrome
3. C.
   Turner's syndrome
4. D.
   Edwards' syndrome

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1. A.
   $\text{CH}_3$, $\text{O}_2$, $\text{NH}_3$, $\text{H}_2\text{O}$ vapour at $1800\,^{\circ}\text{C}$
2. B.
   $\text{CH}_4$, $\text{H}_2$, $\text{NH}_3$, $\text{H}_2\text{O}$ vapour at $800\,^{\circ}\text{C}$
3. C.
   $\text{CH}_4$, $\text{CO}_2$, $\text{H}_2$, $\text{H}_2\text{O}$ vapour at $1800\,^{\circ}\text{C}$
4. D.
   $\text{CH}_4$, $\text{NH}_4$, $\text{SO}_2$, $\text{H}_2\text{O}$ vapour at $800\,^{\circ}\text{C}$

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1. A.
   Hybrid : Heavy, 1 : 16
2. B.
   Light : Heavy, 1 : 31
3. C.
   Hybrid : Heavy, 1 : 31
4. D.
   Light : Heavy, 1 : 05

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1. A.
   Pneumonia
2. B.
   Malaria
3. C.
   Typhoid
4. D.
   Amoebiasis

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1. A.
   Salmonella typhimurium
2. B.
   Streptococcus pneumoniae
3. C.
   Escherichia coli
4. D.
   Haemophilus influenzae

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1. A.
   Upper strand 5' to 3' and lower strand 3' to 5' (left to right); a 5'-3' primer paired at the left end of the upper strand and a 3'-5' primer paired at the right end of the lower strand
2. B.
   Upper strand 5' to 3' and lower strand 3' to 5' (left to right); a 3'-5' primer paired at the right end of the upper strand and a 5'-3' primer paired at the left end of the lower strand
3. C.
   Upper strand 3' to 5' and lower strand 5' to 3' (left to right); a 3'-5' primer paired at the left end of the upper strand and a 5'-3' primer paired at the right end of the lower strand
4. D.
   Upper strand 3' to 5' and lower strand 5' to 3' (left to right); a 3'-5' primer paired at the right end of the upper strand and a 5'-3' primer paired at the left end of the lower strand

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1. A.
   A horizontal line: population density stays constant with time
2. B.
   A straight line rising from the origin: population density increases at a steady rate with time
3. C.
   A curve rising from the origin and becoming steeper and steeper with time
4. D.
   A curve rising from near the origin, becoming steeper, then flattening out to a plateau

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

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

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

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

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1. A.
   n, 2n
2. B.
   2n, n
3. C.
   3n, 2n
4. D.
   2n, 3n

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1. A.
   480
2. B.
   720
3. C.
   1010
4. D.
   2020

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1. A.
   Asteraceae
2. B.
   Solanaceae
3. C.
   Malvaceae
4. D.
   Liliaceae

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1. A.
   Live yeast
2. B.
   Killed yeast
3. C.
   Live bacteria
4. D.
   Killed bacteria

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1. A.
   Less in number
2. B.
   More in number
3. C.
   Both were less in number
4. D.
   Both were more in number

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1. A.
   50% Red : 50% White
2. B.
   25% Pink : 50% White : 25% Red
3. C.
   50% Red : 50% Pink
4. D.
   25% Red : 50% Pink : 25% White

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1. A.
   Down's syndrome
2. B.
   Turner's syndrome
3. C.
   Klinefelter's syndrome
4. D.
   Patau's syndrome

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1. A.
   Upper strand 5' to 3' and lower strand 3' to 5' (left to right); a 5'-3' primer paired at the left end of the upper strand and a 3'-5' primer paired at the right end of the lower strand
2. B.
   Upper strand 5' to 3' and lower strand 3' to 5' (left to right); a 3'-5' primer paired at the right end of the upper strand and a 5'-3' primer paired at the left end of the lower strand
3. C.
   Upper strand 3' to 5' and lower strand 5' to 3' (left to right); a 3'-5' primer paired at the left end of the upper strand and a 5'-3' primer paired at the right end of the lower strand
4. D.
   Upper strand 3' to 5' and lower strand 5' to 3' (left to right); a 3'-5' primer paired at the right end of the upper strand and a 5'-3' primer paired at the left end of the lower strand

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1. A.
   Malaria
2. B.
   Typhoid
3. C.
   Common cold
4. D.
   Pneumonia

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1. A.
   Hybrid : Heavy, 1 : 16
2. B.
   Light : Heavy, 1 : 31
3. C.
   Hybrid : Heavy, 1 : 31
4. D.
   Light : Heavy, 1 : 05

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1. A.
   Thermus aquaticus
2. B.
   Salmonella typhimurium
3. C.
   Escherichia coli
4. D.
   Haemophilus influenzae

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1. A.
   A straight line falling from a high value on the vertical axis to the time axis: population density decreases at a steady rate with time
2. B.
   A curve rising from the origin and becoming steeper and steeper with time
3. C.
   A curve rising from near the origin, becoming steeper, then flattening out to a plateau
4. D.
   A straight line rising from the origin: population density increases at a steady rate with time

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

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

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

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

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1. A.
   Maize
2. B.
   Rose
3. C.
   Mango
4. D.
   Rice

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1. A.
   seeds
2. B.
   spores
3. C.
   gemmules
4. D.
   gametes

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1. A.
   2n, 3n
2. B.
   2n, n
3. C.
   3n, 2n
4. D.
   n, 2n

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1. A.
   160
2. B.
   320
3. C.
   1340
4. D.
   2680

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1. A.
   Less in number
2. B.
   More in number
3. C.
   Both were less in number
4. D.
   Both were more in number

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1. A.
   Turner's syndrome
2. B.
   Down's syndrome
3. C.
   Klinefelter's syndrome
4. D.
   Edwards' syndrome

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1. A.
   25% Red : 50% Pink : 25% White
2. B.
   50% Red : 50% White
3. C.
   50% Pink : 50% White
4. D.
   25% Pink : 50% Red : 25% White

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1. A.
   Epidermophyton
2. B.
   Entamoeba histolytica
3. C.
   Haemophilus influenzae
4. D.
   Salmonella typhi

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1. A.
   Taq polymerase
2. B.
   DNA ligase
3. C.
   Restriction endonuclease
4. D.
   $\beta$-galactosidase

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1. A.
   Hybrid : Heavy, 1 : 16
2. B.
   Light : Heavy, 1 : 31
3. C.
   Hybrid : Heavy, 1 : 31
4. D.
   Light : Heavy, 1 : 05

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1. A.
   A straight line falling from a high value on the vertical axis to the time axis: population density decreases at a steady rate with time
2. B.
   A curve rising from near the origin, becoming steeper, then flattening out to a plateau
3. C.
   A curve rising from the origin and becoming steeper and steeper with time
4. D.
   A straight line rising from the origin: population density increases at a steady rate with time

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1. A.
   Upper strand 5' to 3' and lower strand 3' to 5' (left to right); a 5'-3' primer paired at the left end of the upper strand and a 3'-5' primer paired at the right end of the lower strand
2. B.
   Upper strand 5' to 3' and lower strand 3' to 5' (left to right); a 3'-5' primer paired at the right end of the upper strand and a 5'-3' primer paired at the left end of the lower strand
3. C.
   Upper strand 3' to 5' and lower strand 5' to 3' (left to right); a 3'-5' primer paired at the left end of the upper strand and a 5'-3' primer paired at the right end of the lower strand
4. D.
   Upper strand 3' to 5' and lower strand 5' to 3' (left to right); a 3'-5' primer paired at the right end of the upper strand and a 5'-3' primer paired at the left end of the lower strand

Tap an option to check your answer.

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

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

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

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

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