Final answer:
The correct term for the physical manifestation of a genotype is the organism's phenotype. The phenotype includes all the observable traits of an organism, which are the result of the interaction of its alleles, or its genotype.
Step-by-step explanation:
The physical manifestation of a genotype, like blue eyes for bb, is an organism's phenotype. The phenotype refers to the observable traits expressed by an organism, which result from the interactions of the alleles present in the organism's genotype. By contrast, the term genotype describes the underlying genetic makeup of an organism, which includes both the alleles that are expressed and those that are not. Mendel's hybridization experiments with pea plants illustrated how organisms with different genotypes could have the same phenotype. For instance, both homozygous dominant (BB) and heterozygous (Bb) plants may exhibit the same flower color, which is determined by the dominant allele.
Regarding other options provided in the question, intermediate expression is observed in cases of incomplete dominance, where the phenotype is a blend of dominant and recessive traits. Polyploidy refers to the condition where an organism has more than two complete sets of chromosomes, which is not relevant to the expression of a specific trait. Incomplete penetrance describes situations where a dominant allele does not always manifest in the phenotype, and polygenic traits are traits influenced by multiple genes, which can lead to a wide range of phenotypic expressions.