What is the term used to describe the genetic makeup of an organism based on the combination of alleles?

• A. Chromosome
• B. Genotype
• C. Phenotype
• D. Gene pool

Answer: (B)

Verified step by step guidance

1. Understand the key terms: 'genotype' and 'phenotype'. The genotype refers to the genetic makeup of an organism, specifically the combination of alleles it possesses. The phenotype, on the other hand, refers to the observable characteristics or traits of an organism, which result from the interaction of its genotype with the environment.
2. Recognize that alleles are different forms of a gene that can exist at a specific locus on a chromosome. An organism inherits two alleles for each gene, one from each parent.
3. The term 'genotype' is used to describe the specific allelic combination an organism has for a particular gene or set of genes. This can include homozygous (same alleles) or heterozygous (different alleles) combinations.
4. The 'gene pool' refers to the total collection of genes and their alleles in a population, not the genetic makeup of an individual organism.
5. Therefore, the correct term to describe the genetic makeup of an organism based on the combination of alleles is 'genotype'.