D is the answer I'm pretty sure
Answer:
In a heterozygote, both alleles are expressed. - is the best explanation of codominance.
Explanation:
Closely related to incomplete dominance is codominance, in which both alleles are simultaneously expressed in the heterozygote. Codominance is a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent. If the alleles are different, the dominant allele usually will be expressed, while the effect of the other allele, called recessive, is masked.
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