AP BIOLOGY

HEREDITY

INCOMPLETE DOMINANCE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
In a certain species of animal, black fur (B) is dominant over tan fur (b). Which type of dominance does this cross show?
A
Complete Dominance
B
Incomplete Dominance
C
Codominance
D
Polygenic Inheritance
Explanation: 

Detailed explanation-1: -It is a heterozygous dominant Bb and has black fur.

Detailed explanation-2: -The gene for black fur (B) is dominant over the gene for white fur (b) in mice. A homozygous dominant female and a heterozygous male produce 200 offspring during their lifetime.

Detailed explanation-3: -The black and brown colors do not blend together: the black allele covers up the brown allele. This means that the black allele is dominant over the brown allele. Remember that dominant alleles cover up recessive alleles. If there is one dominant allele present, the dog will appear black.

Detailed explanation-4: -While the genotype tells us what alleles an organism has, the phenotype describes which trait is expressed. So, the phenotype of the dog on the top is black fur, and the phenotype of the dog on the bottom is yellow fur.

Detailed explanation-5: -We the black furred dog has to be genotype aa because he displays the recessive phenotype. The offspring produced from this cross would be 2 Aa and 2 aa genotypes, based on a punnet square.

There is 1 question to complete.