Question

the following results were observed from a mating between two black and white speckled cats: 5 black cats, 12 black and white speckled cats, and 4 white cats. which term describes the relationship between the alleles of the coat color gene?
polygonic
codominance
mendelian
incomplete dominance

Explanation:

• Polygenic: Involves multiple genes affecting a trait. Here, it's about alleles of a single coat - color gene, so this is incorrect.
• Mendelian: Refers to simple dominant - recessive relationships. In this case, we have a third phenotype (black and white speckled) which is not in line with simple Mendelian (where only two phenotypes would be expected from a single - gene cross if it were Mendelian dominant - recessive).
• Codominance: Occurs when both alleles in a heterozygote are fully expressed. The black and white speckled cats show both black and white (the expressions of both alleles), which is characteristic of codominance.
• Incomplete dominance: Results in a blended phenotype (e.g., pink from red and white). But here we have a phenotype with both original colors (not a blend), so this is wrong.

Answer:

Codominance