Which of these terms describes the expression of an organism's genes?

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

Answer: (A)

Verified step by step guidance

1. Understand the key terms: 'Phenotype' refers to the observable characteristics or traits of an organism, such as morphology, development, biochemical or physiological properties, and behavior. 'Genotype' refers to the genetic makeup of an organism; the set of genes it carries. 'Chromosome' is a structure within cells that contains DNA and many genes. 'Allele' is a variant form of a gene.
2. Identify the question: The problem asks for the term that describes the expression of an organism's genes.
3. Relate the terms to the question: The expression of an organism's genes is what we can observe, which aligns with the definition of 'Phenotype'.
4. Differentiate between 'Phenotype' and 'Genotype': While 'Genotype' is the genetic makeup, 'Phenotype' is the expression of these genes, influenced by both genetic and environmental factors.
5. Conclude with the correct term: Based on the definitions and the context of the question, 'Phenotype' is the term that describes the expression of an organism's genes.