What is an observable characteristic? (e.g. a person’s height or skin color) Locus Phenotype Allele Genotype
The correct answer and explanation is:
Correct Answer: Phenotype
Explanation (300 words):
An observable characteristic, such as a person’s height, eye color, skin tone, or blood type, is referred to as a phenotype in genetics. The phenotype is the physical and behavioral expression of an individual’s genes (genotype) as influenced by environmental factors.
For example, two individuals might have the same genotype for height, but one may grow taller due to better nutrition, showing that environment also plays a role in shaping the phenotype.
To understand why phenotype is the correct answer, it’s helpful to distinguish it from the other terms:
- Genotype refers to the genetic makeup of an organism. It includes the specific DNA sequences or alleles that an organism inherits from its parents. While genotype determines the potential traits, not all genotypes are visibly expressed.
- Allele is a version of a gene. For example, a gene for eye color may have a brown allele and a blue allele. The combination of alleles (dominant or recessive) contributes to the genotype.
- Locus (plural: loci) is the specific location of a gene on a chromosome. It does not describe a trait itself, but rather where the gene responsible for a trait is found.
Therefore, phenotype is the most accurate term for traits or characteristics that can be observed or measured. These include physical traits (like height, skin color, and eye color), biochemical traits (like blood type), and even behavioral traits (like temperament).
In summary, the phenotype is the outward expression of an organism’s genetic code as influenced by both heredity and environment, making it the correct term for any observable characteristic.