Define each term to understand their meanings:
- Phenotype: The observable characteristics or traits of an organism, such as its morphology, development, biochemical or physiological properties, and behavior.
- Allele: A variant form of a gene. Different alleles can result in different traits.
- Genotype: The genetic constitution of an organism, specifically the alleles present at a given set of loci.
- Chromosome: A long DNA molecule with part or all of the genetic material of an organism.