Which term denotes the observable traits due to gene-environment interactions?

• A. Genotype
• B. Locus
• C. Allele
• D. Phenotype

Answer: (D)

The observable traits that arise when genes interact with the environment are called the phenotype. A phenotype is what you can see or measure, shaped by the genetic blueprint (genotype) and by environmental factors such as nutrition, temperature, and lifestyle. For example, height is influenced by genetic potential but also by nutrition and health during growth, so the final height you observe is the phenotype. The genotype is the underlying genetic makeup that provides the potential, while the environment helps determine how that potential is realized. Locus is the gene’s location on a chromosome, and allele is a variant form of a gene—neither describes the observable trait itself.