Explanation:
Roan coat in cattle is an example of codominance, which is a type of inheritance where both alleles of a gene are expressed equally in a heterozygous individual. In this case, the roan coat is a mixture of white hairs and colored hairs (usually red or black), which are both expressed in the heterozygous individual.

Examples of Codominance:

- Blood type: The ABO blood group system is an example of codominance, where both A and B alleles are expressed equally in individuals with AB blood type.

- Feather color in chickens: Some chicken breeds exhibit codominance in their feather color inheritance. For example, in the Andalusian breed, the blue allele and the black allele are codominant, so a heterozygous individual will have feathers that are a mixture of blue and black.

- Sickle cell anemia: Sickle cell anemia is a genetic disorder caused by a codominant allele. Individuals who are homozygous for the sickle cell allele have the disease, while those who are heterozygous have a milder form of the disease called sickle cell trait.

Comparison with Other Types of Inheritance:

- Incomplete dominance: In incomplete dominance, the heterozygous phenotype is intermediate between the two homozygous phenotypes. For example, in snapdragons, red and white flowers produce pink flowers in the heterozygous offspring.

- Multiple allelism: Multiple allelism refers to the presence of more than two alleles of a gene in a population. For example, the ABO blood group system has three alleles: A, B, and O. However, codominance can still occur in multiple allelic systems, as seen in the AB blood type.

In summary, roan coat inheritance in cattle is an example of codominance, where both white and colored hairs are expressed equally in the heterozygous individuals.