Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
How is a codominant trait expressed in an organism?
A
Neither allele is expressed, resulting in a lack of the trait.
B
One allele is dominant over the other, masking the recessive trait.
C
The alleles blend together to form an intermediate phenotype.
D
Both alleles are fully expressed, resulting in a phenotype that shows both traits equally.
Verified step by step guidance
1
Understand the concept of codominance: In genetics, codominance occurs when two different alleles for a gene are both expressed equally in the phenotype of an organism.
Identify the key characteristic of codominance: Unlike complete dominance, where one allele masks the other, or incomplete dominance, where alleles blend, codominance results in both alleles being fully and equally expressed.
Consider examples of codominance: A classic example is the ABO blood group system, where both A and B alleles are expressed in individuals with AB blood type, resulting in a phenotype that shows characteristics of both alleles.
Differentiate codominance from other genetic expressions: Compare codominance with complete dominance (one allele masks another) and incomplete dominance (alleles blend to form an intermediate phenotype) to understand how codominance uniquely allows both alleles to be visible in the phenotype.
Apply the concept to the problem: Recognize that the correct expression of a codominant trait is when both alleles are fully expressed, resulting in a phenotype that shows both traits equally, as stated in the problem.