Codominance and Incomplete Dominance Answer Key Introduction:
Dominant and recessive alleles have always been the most talked-about concept when it comes to genetics, but there are two other types that you should know: codominance and incomplete dominance. These two types of genetic inheritance are slightly different but equally important. In this post, we will discuss what codominance and incomplete dominance are, how they are different from each other, and provide you an answer key for some of the most frequently asked questions about these concepts.
Blog Body:
- What is Codominance?
Codominance is a type of genetic inheritance where two alleles of a gene are equally expressed in the phenotype of the organism. In other words, neither allele is dominant nor recessive. This results in a phenotype that shows both traits expressed. For example, a chicken that has both black and white feathers due to two different alleles of the same gene is said to have codominance.
- What is Incomplete Dominance?
Incomplete dominance, on the other hand, is a type of genetic inheritance where one allele is not completely dominant over the other, and the resulting phenotype is a blend of the traits of both alleles. For example, in snapdragons, red flowers are dominant to white flowers, but when a red-flowered plant is crossed with a white-flowered one, the offspring has pink flowers, showing incomplete dominance.
- How are they different?
The key difference between the two is that in codominance, both alleles are equally expressed, while in incomplete dominance, one allele is not fully dominant, and there is a blending of traits in the phenotype. In other words, both alleles are visible in codominance, while only a mix of them is visible in incomplete dominance.
- How to differentiate between Codominance and Incomplete Dominance?
It can be confusing to differentiate between the two since they both involve the blending of traits, but there are a few key differences that can help you tell them apart. Codominance occurs when two different alleles of the same gene are equally expressed, leading to a phenotype that shows both traits clearly. In contrast, incomplete dominance occurs only when one allele is not fully dominant, leading to a phenotype that is a mix of both traits. Additionally, codominance shows both alleles in a heterozygous individual (Aa), while incomplete dominance shows a blending of alleles in the heterozygous individual.
- Examples of Codominance and Incomplete Dominance:
Here are a few more examples you can use to differentiate codominance from incomplete dominance:
Codominance:
Blood Types: The A and B alleles of the blood group gene are both equally expressed in the phenotype, resulting in the AB blood type that shows traits of both A and B.
Incomplete Dominance:
Flower Color: Snapdragons with their pink flowers are an example of incomplete dominance since they are a result of two different alleles of the same gene that blend together to create a third color.
Conclusion:
In conclusion, codominance and incomplete dominance are two types of genetic inheritance that are essential to understand when it comes to studying genetics. Codominance is expressed when both alleles of a gene are equally expressed, while incomplete dominance is expressed when one allele is not fully dominant over the other. By understanding their definitions and differences, we can better grasp the concept of genetics and its various aspects, including inheritance.
