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Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYPrinciples of Inheritance and Variation1 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: Quantitative inheritance is called polygenic inheritance.
Reason: Several genes control the expression of a trait.
  • ✓
    Both assertion and reason are true and reason is the correct explanation of assertion.
  • B
    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: A.
Both assertion and reason are true and reason is the correct explanation of assertion.
Quantitative inheritance is a type of inheritance controlled by one or more genes in which the dominant alleles have cumulative effect with each dominant allele expressing a part or unit of the trait, the full trait being shown only when all the dominant alleles are present. The genes involved in quantitative inheritance are called polygenes. A polygene is defined as a gene where a dominant allele controls only a unit or partial quantitative expression of a trait.

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