Chapter 1, Problem 5CONQ

Summary Introduction

To review:

Whether the following examples are description of genetics at the molecular, cellular, organism or population level.

A. The Hb^S allele encodes a polypeptide that functions slightly differently from the polypeptide encoded by the Hb^A allele.

B. If an individual has two copies of the Hb^s allele, that person’s red blood cells take on a sickle shape.

C. Individuals who have two copies of the Hb^A allele do not have sickle cell disease, but they are not resistant to malaria. People who have one Hb^A allele and one Hb^S allele do not have sickle cell disease and are resistant to malaria. People who have two copies of the Hb^S allele have sickle cell disease and this disease may significantly shorten their lives.

D. Individuals with sickle cell disease have anemia because their red blood cells are destroyed by the body.

Introduction:

The blood disease called sickle cell anemia is a heritable disease. The affected individuals do not have enough oxygen-carrying hemoglobin in their blood, which causes the red blood cells (RBCs) to shrink and acquire a sickle shape. This happens due to the defective β–globin gene.