Florida Biology EOC Practice Test

In codominance, traits from both alleles are:

1. Deleted in the offspring

2. Ignored in the offspring

3. Not used in the offspring

4. Expressed in the phenotype of offspring

The correct answer is: Expressed in the phenotype of offspring

In codominance, both alleles contribute to the phenotype, which means that the traits from both alleles are fully expressed in the offspring. This results in a phenotype that exhibits characteristics of both parental traits simultaneously. A classic example of this can be seen in certain breeds of cattle, where an offspring may show patches of both red and white fur if one parent has a red allele and the other has a white allele. In such cases, neither allele is dominant or recessive; instead, both are expressed in the physical appearance of the organism. This is distinct from other genetic concepts, such as complete dominance where only one trait is expressed, overshadowing the other. In codominance, each trait retains its characteristics, leading to a unique and combined phenotype that reflects both alleles.