Codominance and Incomplete Dominance

1. Codominance and Incomplete Dominance

2. Dominance • What is dominance? • What makes a gene dominant? • What makes a gene recessive? • These factors affect most genes and cause them to be expressed or hidden

3. Dominance • Some genes do not play by the same rules • These genes have special ways of being expressed • These genes are not dominant or recessive

4. Codominance • There are several genes that have two different dominant traits • If these two dominant traits are expressed at the same time we call it codominance • Codominantgenes are genes that express both alleles in the pairing

5. Codominance • We call them codominant genes because both alleles in the gene are expressed • Both dominant traits are represented in organisms

6. Codominance • Cows are a great example of codominance • There are cows that are a red color • There are cows that are a white color • Both of those cows have a dominant phenotype • However when we have one dominant gene that is white and one that is red we have both expressed

7. Codominance

8. Incomplete Dominance • Sometimes genes do not have such an easy idea for dominance • Sometimes with genes there is no defined dominant gene • When there are two different genes that are considered dominant, they can blend

9. Incomplete Dominance • Genes that blend with two dominant alleles are called incomplete dominance genes • These genes can be found in many different types of organisms

10. Incomplete Dominance • Snapdragons are a good example of incomplete dominance • There are red Snapdragons • There are white Snapdragons • There are also pink Snapdragons that are formed with a heterozygous genotype

11. Incomplete Dominance