Question

When single gene exhibits multiple phenotypic expression, the phenomenon is called ____

• A. Pleiotropy
• B. Co-dominance
• C. Polygenic inheritance
• D. Incomplete dominance

Hint:

Pleiotropy is exemplified by conditions like Marfan syndrome, where one gene affects multiple systems.

Answer 1

The Correct Option is A

• Genetic Phenomena:
  • Pleiotropy: A single gene influences multiple, seemingly unrelated phenotypic traits.
  • Co-dominance: Both alleles in a heterozygote are fully expressed.
  • Polygenic inheritance: Multiple genes contribute to a single trait.
  • Incomplete dominance: One allele is not fully dominant, resulting in an intermediate phenotype.
• Option Analysis:
  • (1) Pleiotropy: Correct, as it describes a single gene affecting multiple phenotypes.
  • (2) Co-dominance: Incorrect, relates to allele expression, not multiple traits.
  • (3) Polygenic inheritance: Incorrect, involves multiple genes, not one.
  • (4) Incomplete dominance: Incorrect, pertains to blending of traits, not multiple effects.
• Conclusion: The correct answer is (1) Pleiotropy.