The physical appearance of an organism produced by genotype and environment is its

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

Answer: (B)

Phenotype is the observable traits of an organism—the physical appearance and traits we can see or measure—that result from how its genes are expressed in a given environment. The genotype is the genetic makeup, the actual alleles an organism carries, which provides the potential for traits. An allele is one variant form of a gene, and a locus is the specific location of that gene on a chromosome. Environmental factors can influence how genes are expressed, so the same genotype can produce different phenotypes under different conditions. For example, height or fur color can be affected by nutrition or temperature, illustrating how genotype and environment together shape the phenotype.