10. Inherited medical conditions and codominance

10. Inherited medical conditions and codominance

Monohybrid inheritance

Inheritance in which both parents are heterozygous for a trait

Heterozygous individuals

Which individuals are carriers of albinism? Heterozygous individuals

melanin

People with albinism do not produce:

Melanin

A pigment that normally makes skin, the iris of the eye and hair a dark color

recessive

The allele for albinism is …

A heterozygous individual

Carrier

Sickle cell anemia

A condition in which a homozygote has the disease but a heterozygous individual may gain some benefit in certain environments

abnormal hemoglobin and sickle-shaped red blood cells

A change in the base sequence of the gene for hemoglobin results in…

They are resistant to malaria, and are only a little bit anemic so they don’t die from either malaria or anemia.

What benefit do carriers of sickle cell anemia have?

Codominance

When two alleles for a trait are equally expressed with neither being recessive or dominant

Because dominant alleles are not hidden in the phenotype, which means the disease is easy to be spotted and can be diagnosed early to prevent worsening.

Why is a dominant allele that causes a serious disease more likely to disappear from a population?