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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 $\text{(a), (b), (c)}$ and $(d)$ as given below.
Assertion: Complementary genes are non-allelic genes.
Reason: Complementary genes interact to produce a completely new trait.
  • 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.
Complementary genes are those non-allelic genes which independently show a similar effect but produces a new trait when present together in the dominant form. $W$. Bateson and $R.C.$ Pun nett observed that, when two white flowered varieties of sweet pea, Lathyrus odoratus were crossed, $F_1$ progeny had coloured flowers. When $F$ Frogeny obtained from $F_1$ was classified, plants with coloured flowers and those with white flowers were obtained in $9: 7$ ratio. The two dominants are brought together in $F1$ generation and therefore coloured flowers are produced.

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