Final answer:
Phenotypes are the observable characteristics of an organism, resulting from the production of proteins based on the genotype and environmental interactions. Genotypic expressions of dominant and recessive alleles, such as in the expression of flower color, contribute to these observable traits. Phenotypic ratios reflect these physical traits, while genotypic ratios account for the underlying gene combinations.
Step-by-step explanation:
Phenotypes are seen due to the production of proteins from the genotypic code found in the nucleus. A cell's genotype, which is the full collection of genes it contains, along with interactions with the cell's environment, influence the production of proteins. These proteins, in turn, result in the expression of the cell's phenotype, or the set of observable characteristics.
Genetic expression is influenced by whether an allele is dominant or recessive, as explained by Mendelian inheritance. For example, the genotype 'BB' or 'Bb' can both result in a phenotype of purple flowers because the dominant allele 'B' is expressed over the recessive allele 'b', which does not influence the phenotype when paired with a dominant allele.
Therefore, a phenotype reflects the physical expression of a trait transmitted by alleles and can be observed in the phenotypic ratios. In contrast, the genotypic ratios represent the combinations of genes that may not always be distinguishable in the phenotypes, as some alleles do not affect the phenotype when not expressed.