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Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYMolecular Basis of Inheritance1 Mark
MCQ
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. Assertion : The uptake of $\text{DNA}$ during transformation is an active, energy requiring process.
Reason: Transformation occurs in only those bacteria, which possess the enzymatic machinery involved in the active uptake and recombination.
  • A
    Both assertion and reason are true, and reason is the correct explanation of assertion.
  • ✓
    Both assertion and reason are true, but reason is not the correct explanation of assertion.
  • C
    Assertion is true, but reason is false.
  • D
    Both assertion and reason are false.
✓

Answer

Correct option: B.
Both assertion and reason are true, but reason is not the correct explanation of assertion.
Transformation does not involve passive entry of $\text{DNA}$ molecules through permeable cell walls and membranes. It does not occur $'$naturally$'$ in all species of bacteria, only in those species possessing the enzymatic machinery involved in the active uptake and recombination processes. Even in these species, all cells in a given population are not capable of active uptake of $\text{DNA}$. Only competent cells, which possess a so-called competence factor are capable of serving as recipients in transformation.

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