Sickle-cell anemia:

1)   Sickle-cell anemia is caused by an abnormal hemoglobin molecule that changed the shape of red blood cells. This disease can lead to various health complications that are often lethal. However, heterozygous individuals have minor symptoms. Moreover, heterozygous individuals show an advantage with decreased vulnerability to Malaria.  The allele for Sickle-cell anemia is most common in tropical areas where malaria is common. Which population genetics phenomenon could be responsible for this?

2)   Given what you know about how Natural Selection works, explain why Sickle cell disease hasn't been eradicated from the population.

3)   Social unrest in West Africa, where Sickle cell anemia is most common, is forcing people to migrate to other countries. As a result, sickle cell anemia cases are rising in Europe and the US in recent years. Is the US population in Hardy-Weinberg equilibrium? If not, which population genetics phenomenon could be responsible for this?

4)  Let's say that Robert Baratheon, despite being king, was unlucky enough to be heterozygous from Huntington's disease and heterozygous polycystic kidney disease-2 (caused by a mutation in the Polycystin-2 gene). However, being king allowed him to have many children with multiple concubines, none of which had any alleles for these diseases. Of the 16 children he fathered, 6 didn't inherit any disease while the other 7 inherited both, and 3 only inherited either one of the diseases. What can you infer about the location of the Huntingtin gene and the Polycystin-2 gene?

5)   What event led some children having only one of the diseases?

6)   Did Robert inherit both diseases from the same parent or could he have inherited one disease from each parent? Explain, draw Robert's chromosomes.

7)   One of Robert's sons is colorblind (a sex-linked condition) and will not be able to become a warrior. He is very upset and ordered his concubine to be beheaded. Was she at fault?

8)  Sickle-cell disease is caused by a mutation in the hemoglobin gene located on chromosome 11. While Huntington's disease is caused by a mutation in the Huntingtin gene located on chromosome 4. What can you infer about the inheritance of these diseases? Would they satisfy Mendelian ratios?