Question

Represented below is the inheritance pattern of a certain type of traits in humans, Which one of the following conditions could be an example of this pattern?

• A. Phenylketonuria
• B. Sickle-cell anaemia
• C. Haemophilia
• D. Thalassemia

Answer 1

The correct option is C Haemophilia

Haemophilia could be an example of this pattern. The gene of hemophilia goes to son from mother and to daughter from the father. It is a sex-linked or X-linked diseases. X-linked inheritance means that the gene causing the trait or the disorder is located on the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome.In this disease, the blood fails to clot when there is a cut resulting in continuous bleeding that leads to death.
Thalassemia, phenylketonuria, and sickle anemia are autosomal recessive disorders. An autosomal recessive disorder means two copies (one form each parent) of an abnormal gene must be present in order for the disease or trait to develop.