Question

Roan cattle show codominance for the color of their hair. There are alleles for red hair and white hair. What would you expect a heterozygous roan bull to look like if the trait showed incomplete dominance instead?
A It would be red.
B It would be white.
C It would be spotted.
D It would be pink.

Answer 1

The right answer is D.

* Incomplete dominance is when hybrids of the F1 generation have an intermediate phenotype (between the two phenotypes) compared to the parental generation P1. This phenomenon occurs in heterozygous individuals.

We have an example of an incomplete dominanace in this case, where we have a mixture of the two colors of the two alleles. The pink color obtained in the F1 generation is incomplete dominance. These species are heterozygous.

* For codominance it is different, There are some cases where the two alleles of a gene are completely and independently manifested in the phenotype in a heterozygous individual. Both of these alleles are said to be codominant.

For example, a chicken with a variegated plumage that was obtained by crossing a white hen with a black rooster. One might expect gray offspring, but since we have a dominant allele for the black color and a dominant allele for the white color, we obtain a white and black plumage.

Answer 2

A heterozygous roan bull would look like pink. Hence, option D is correct.

Further Explanation:

Codominance is known to be the relationship between the two versions of the gene. People get one version of a gene, known as allele, from each parent. When the alleles are not same, then dominant allele generally expresses while the effect of the other allele (recessive allele) is masked. The common example of this kind of dominance is observed in ABO blood group.

Incomplete dominance occurs when the dominant allele or form of the gene which does not fully masks the effects of recessive allele and displays the blending of both alleles in physical appearance. This is also called as partial or semi-dominance. The common example of this is observed in roses. The red color works as a dominant trait while recessive trait is white. However, the heterozygous roses are pink. This is different from codominance, which is when both alleles are expressed at one time. Hence, in the given case, heterozygous roan bull will display pink color.

Learn More:

1. Learn more about the fibrous skeleton of the heart brainly.com/question/7301375
2. Learn more about blood cells bring oxygen and take carbon dioxide away brainly.com/question/1213217
3. Learn more about the system prepares food for absorption into the bloodstream brainly.com/question/310282

Answer Details:

Grade: High school

Subject: Biology

Chapter: Genetics

Keywords:

Roan bull, codominance, incomplete dominance, red color, dominant allele, a recessive allele, masking, blending, pink, white, ABO blood grouping, roses.