Why are there so many phenotypes in polygenic inheritance?
In polygenic inheritance, the genes contributing to a trait have equal influence and the alleles for the gene have an additive effect. In incomplete dominance, one allele does not completely dominate or mask another. The phenotype is a mixture of the phenotypes inherited from the parent alleles.
How many phenotypes can be expressed?
Answer: only four phenotypes result from the six possible ABO genotypes. How does this happen? To understand why this occurs, first note that the A and B alleles code for proteins that exist on the surface of red blood cells; in contrast, the third allele, O, codes for no protein.
What are the 5 phenotypes?
Phenotype Examples
- Eye color.
- Hair color.
- Height.
- Sound of your voice.
- Certain types of disease.
- Size of a bird’s beak.
- Length of a fox’s tail.
- Color of the stripes on a cat.
Which is not a polygenic trait?
Blood type AB in humans, for instance, is not a polygenic trait. Rather, it is a case of codominance. The two alleles for A and B antigens on the red blood cells of blood type AB individuals are dominant, and therefore are expressed together.
Is AA a genotype or phenotype?
Table 4-5. Correlation of ABO phenotypes and genotypes.
| Phenotype | Possible Genotype |
|---|---|
| A | AA or AO |
| B | BB or BO |
| AB | AB |
| O | OO |
What traits are polygenic?
Polygenic Trait A polygenic trait is one whose phenotype is influenced by more than one gene. Traits that display a continuous distribution, such as height or skin color, are polygenic.
What traits are often polygenic?
Because multiple genes are involved, polygenic traits do not follow Mendel’s pattern of inheritance. Instead of being measured discretely, they are often represented as a range of continuous variation. Some examples of polygenic traits are height, skin color, eye color, and hair color.
What are the 6 blood type genotypes?
The different possible genotypes are AA, AO, BB, BO, AB, and OO. How are blood types related to the six genotypes? A blood test is used to determine whether the A and/or B characteristics are present in a blood sample.
