Question

How may types of gametes will be formed by a parent with genotype ‘AaBbCc’?

• A. 8
• B. 12
• C. 6
• D. 4

Hint:

Gamete types = $2^n$, where $n$ is the number of heterozygous gene pairs.

Answer 1

The Correct Option is A

• Gamete Formation: The number of gamete types is determined by the formula $2^n$, where $n$ is the number of heterozygous gene pairs.
• Genotype Analysis: The genotype ‘AaBbCc’ has three heterozygous pairs (Aa, Bb, Cc), so $n = 3$.
• Calculation: $2^3 = 8$ possible gamete combinations (ABC, ABc, AbC, Abc, aBC, aBc, abC, abc).
• Option Analysis:
  • (1) 8: Matches the calculation. Correct.
  • (2) 12: Incorrect, exceeds the possible combinations.
  • (3) 6: Incorrect, does not fit $2^n$ for 3 pairs.
  • (4) 4: Incorrect, corresponds to $2^2$ (two heterozygous pairs).
• Conclusion: The correct answer is (1) 8, as a parent with genotype AaBbCc can form 8 types of gametes.