Define genotype and phenotype and explain how genotype can influence phenotype with a dominant/recessive example.

Define genotype and phenotype and explain how genotype can influence phenotype with a dominant/recessive example.

• A. Genotype is the allele combination; phenotype is the observable trait; e.g., tall (dominant) vs short (recessive) in pea height.
• B. Genotype is the observable trait.
• C. Phenotype is the allele combination.
• D. Genotype and phenotype are always the same.

Answer: (A)

The main idea here is how genetic makeup determines observable traits. Genotype refers to the specific alleles an organism carries for a gene, while phenotype is the trait you can see. In a classic dominant/recessive example for height, the tall allele (T) is dominant over the short allele (t). If an organism has at least one tall allele (TT or Tt), it will be tall. Only with two copies of the recessive allele (tt) does the short phenotype appear. This shows how the combination of alleles directly shapes what you observe. Environment or other genetic factors can influence traits in other cases, but for a simple single-gene dominant/recessive scenario, the genotype determines the phenotype as described.

The main idea here is how genetic makeup determines observable traits. Genotype refers to the specific alleles an organism carries for a gene, while phenotype is the trait you can see. In a classic dominant/recessive example for height, the tall allele (T) is dominant over the short allele (t). If an organism has at least one tall allele (TT or Tt), it will be tall. Only with two copies of the recessive allele (tt) does the short phenotype appear. This shows how the combination of alleles directly shapes what you observe. Environment or other genetic factors can influence traits in other cases, but for a simple single-gene dominant/recessive scenario, the genotype determines the phenotype as described.