Question

Choose the correct option-

A gene showing codominance has?

• A. Both alleles are independently expressed in the heterozygote
• B. Alleles that are recessive to each other
• C. One allele is dominant on the other
• D. Alleles are tightly linked on the same chromosome

Answer 1

The correct option is A

Both alleles are independently expressed in the heterozygote

The correct option is A.

The explanation for Correct option:

1. Co-dominance is a type of inheritance pattern in which multiple variants or alleles are present for the same gene.
2. The expression of each allele brings about a particular phenotype.
3. Alleles are expressed independently of each other in heterozygotes.
4. Example- The color of flowers in the Rhododendron plant results in the formation of flowers with red and white patches.

The explanation for Incorrect option:

Option B

1. If both alleles are recessive to each other, the final trait developed is homozygous recessive in nature.
2. Example- The presence of two wrinkled alleles results in the development of wrinkled seeds in pea plants.

Option C

1. If one allele is dominant compared to another allele, the final trait formed is heterozygous dominant.
2. The final trait developed is the dominant character.
3. Example- The presence of one allele for round seed and one allele for wrinkled seed results in the expression of the heterozygous dominant trait or round seeds.

Option D

1. Tight linking of alleles results in genetic recombination.
2. The DNA sequences undergo breaking, rejoining, and rearrangement.

Final answer

A gene showing codominance has both alleles independently expressed in the heterozygote.