Question

this passage describes the coat graying trait in horses:
your hair may turn gray or white as you grow older. some horses go through a similar process called coat graying as they age. these horses are usually a darker color, such as brown or black, when they are born. over time, the hairs of their coats lose their original color and become gray or white.
in a group of horses, some individuals have coat graying and others do not. in this group, the gene for the coat graying trait has two alleles. the allele g is for having a graying coat, and the allele g is for not having a graying coat.
rudolph, a horse from this group, has coat graying. rudolph has two alleles for having a graying coat.
based on this information, click the blue words to correct any errors in the text.
rudolphs phenotype for the coat graying gene is gg.
rudolph is heterozygous for the coat graying gene.
rudolph has coat graying. this is rudolphs genotype for the coat graying trait.

Explanation:

• Phenotype: Phenotype refers to the observable physical or biochemical characteristics of an organism. Since Rudolph has two alleles for having a graying coat (\(GG\)), the phenotype is coat graying (not \(Gg\) which is a genotype).
• Heterozygous: Heterozygous means having two different alleles for a particular gene. But Rudolph has two of the same alleles (\(GG\)), so it should be homozygous.
• Genotype: Genotype is the genetic makeup of an organism. Rudolph having coat graying is a phenotype. The genotype is \(GG\).

Answer:

• Change “phenotype” to “genotype” and “\(Gg\)” to “\(GG\)” in “Rudolph's phenotype for the coat graying gene is \(Gg\)”.
• Change “heterozygous” to “homozygous” in “Rudolph is heterozygous for the coat graying gene”.
• Change “genotype” to “phenotype” in “Rudolph has coat graying. This is Rudolph's genotype for the coat graying trait”.