Question

Belling's Copy-Choice Theory explains the mechanism of __________.

• A. linkage
• B. crossing over
• C. transformation
• D. inversion

Hint:

Think about what classical model of recombination came before the breakage and reunion model.

Answer 1

The Correct Option is B

Step 1: Belling proposed the Copy-Choice model in 1933 to explain how crossing over happens during meiosis.

Step 2: The idea was that a new DNA strand is built by copying first one parental strand and then switching to copy the other parental strand, so the new strand becomes a recombinant.

Step 3: This model was later replaced by the breakage and reunion model, which is now accepted as the actual mechanism, but the question asks what Belling's theory itself was proposed to explain, which is crossing over.

Step 4: Linkage, transformation and inversion are separate genetic phenomena not addressed by this theory, so option (B) is correct.