Final answer:
An organism's phenotype refers to its observable characteristics, which result from the expression of alleles in its genotype. The phenotype includes traits like hair color and height and is not exclusively determined by only dominant or recessive alleles.
Step-by-step explanation:
The organism's appearance or other detectable characteristics that you can observe, such as hair color, skin color, height, and build, are referred to as its phenotype. It's the expression of the organism's genotype, which is the combination of alleles (the versions of a gene) inherited from the parents. While dominant alleles will express their traits when present, recessive alleles only express their traits in the absence of a dominant allele. Notably, an organism can have a different genotype, for instance, being heterozygous for a gene, but still have the same phenotype as another organism that is homozygous dominant because the dominant allele manifests in the phenotype.