Question

what is a phenotype? a different version of a gene the written expression of two alleles a specific characteristic of a living thing an actual physical trait resulting from alleles

Explanation:

A phenotype is the observable physical or biochemical characteristics of an organism, which are determined by both genetic makeup (genotype) and environmental influences. It is the actual physical trait resulting from alleles (different forms of a gene).

• Option 1: A different version of a gene is called an allele, not a phenotype.
• Option 2: The written expression of two alleles refers to the genotype (e.g., \(Aa\), \(AA\)), not the phenotype.
• Option 3: A specific characteristic of a living thing is a very broad description. The phenotype is more specifically the physical trait due to genetic and environmental factors.
• Option 4: This correctly defines phenotype as the actual physical trait resulting from alleles (along with environmental factors in some cases).

Answer:

D. An actual physical trait resulting from alleles