Which statement best describes polygenic inheritance?

Which statement best describes polygenic inheritance?

• A. Polygenic inheritance
• B. Sex-linked inheritance
• C. Codominant inheritance
• D. Environmental inheritance

Answer: (A)

Polygenic inheritance involves traits that are controlled by many genes, with each gene contributing a small amount to the overall phenotype. Because multiple loci add up their small effects, these traits show continuous variation rather than discrete categories—for example, height, skin color, and eye color vary along a spectrum rather than as simple tall/short or light/dark. This additive effect across many genes is what the term conveys most directly, which is why it’s the best description. In contrast, sex-linked inheritance refers to genes on the X or Y chromosome and often shows sex-specific patterns; codominant inheritance is when both alleles in a heterozygote are fully expressed (like AB blood type); environmental inheritance emphasizes environmental factors shaping traits, which is not the same as the genetic multigenic control described by polygenic inheritance.

Polygenic inheritance involves traits that are controlled by many genes, with each gene contributing a small amount to the overall phenotype. Because multiple loci add up their small effects, these traits show continuous variation rather than discrete categories—for example, height, skin color, and eye color vary along a spectrum rather than as simple tall/short or light/dark. This additive effect across many genes is what the term conveys most directly, which is why it’s the best description.

In contrast, sex-linked inheritance refers to genes on the X or Y chromosome and often shows sex-specific patterns; codominant inheritance is when both alleles in a heterozygote are fully expressed (like AB blood type); environmental inheritance emphasizes environmental factors shaping traits, which is not the same as the genetic multigenic control described by polygenic inheritance.