Final answer:
Incomplete dominance refers to a situation where a heterozygous genotype creates an intermediate phenotype. Variable expressivity is the degree or extent to which a particular genotype is expressed as a phenotype, and it can vary from mild to severe. Examples of incomplete dominance can be seen in snapdragons, while variable expressivity can be observed in conditions like neurofibromatosis.
Step-by-step explanation:
In genetics, if a mutant genotype exhibits a wild-type phenotype, it is known as incomplete dominance.
This is when a heterozygous genotype creates an intermediate phenotype.
Only one allele at the single locus is expressed in a dosage-dependent manner, resulting in an intermediate phenotype.
For example, in snapdragons, a cross between a homozygous parent with white flowers and a homozygous parent with red flowers will produce offspring with pink flowers.
On the other hand, if a mutant genotype exhibits a mild versus severe mutant phenotype, it is an example of variable expressivity.
Variable expressivity refers to the degree or extent to which a particular genotype is expressed as a phenotype.
It can vary from mild to severe, even among individuals with the same genotype. A well-known example is neurofibromatosis, where individuals with the same genetic mutation can exhibit different symptoms and severity.