What term describes the genetic makeup of an organism?

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

Answer: (D)

Genotype is the genetic constitution of an individual—the specific alleles it carries for its genes. This is what we mean by the genetic makeup. It’s different from phenotype, which is the outward traits you can observe and that result from both genotype and environment. It’s also distinct from genome, which is the entire set of genetic material in the organism. For example, for a gene with alleles B and b, the possible genotypes are BB, Bb, or bb, representing the organism’s particular genetic makeup for that gene. So the term that describes the genetic makeup is genotype.