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Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYMolecular Basis of Inheritance1 Mark
Question
For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.

Assertion: Sequences of bases in one polynucleotide chain of DNA can determine the sequence of bases in the other chain.

Reason: In a DNA, amount of adenine equals that of thymine and amount of guanine equals that of cytosine, i.e., A = T and C = G.

✓

Answer

  1. Both assertion and reason are true, but reason is not the correct explanation of assertion.

Explanation:

Although A = T and C = G, there is no any restriction or sequence of bases in one polynucleotide chain. Since A is always linked to T and C to G as determined from the above evidences, sequence of bases in one of polynucleotide should determine the sequence of bases in the other polynucleotide of the double helix.

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