The difference is due to the inheritance pattern. Blood type needs two recessive alleles to express Rh-. Color-blindness needs only one.
<h3>What are the blood type and Color-blindness inheritance patterns?</h3>
⇒ Blood type is coded by a diallelic Rh gene that expresses complete dominance.
The allele Rh+ dominates over the allele Rh-.
Genotyopes and Phenotypes are as follows,
- Individuals Rh+Rh+ express the possitive phenotype
- Individuals Rh+Rh- express the possitive phenotype
- Individuals Rh-Rh- express the negative phenotype.
To express Rh-, a person must inherit<u> two</u><u> recessive alleles</u> from their parents.
⇒ Color-blindness is an X-linked condition coded by a recessive allele.
As most sex-linked genes, it is transmitted together with the X chromosome.
The phenotype depends on the number of recessive alleles and the sex of the person.
Genotyopes and Phenotypes are as follows,
- X⁺X⁺ women have normal sight.
- X⁻X⁻ women are completely color-blinded
- X⁺X⁻ women are partially color-blinded.
- X⁺Y Men are not color-blinded
- X⁻Y Men are color blinded.
In this case, only one recessive allele is enough to express the affection.
In conclusion, Blood type needs two recessive alleles to express Rh-. Color-blindness needs only one recessive allele.
You can learn more about the inheritance pattern at
brainly.com/question/25303949
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