LIFE SCIENCE

Detailed explanation-1: -The sickle cell anemia is caused by single point mutation (an adenine-thymine substitution) that affects the 6th codon of the HBB gene encoding the hemoglobin subunit (-globin).

Detailed explanation-2: -In sickle cell anemia, the hemoglobin chain has a single amino acid substitution, causing a change in both the structure and function of the protein.

Detailed explanation-3: -Because an amino acid has been altered in sickle cell anemia, we can say that the amino acid sequence for hemoglobin has been changed. The amino acid sequence is defined as the primary structure for a protein, so that is the level that has been altered.

Detailed explanation-4: -People who have sickle cell disease inherit two faulty hemoglobin genes, called hemoglobin S-one from each parent. A person has sickle cell trait when the hemoglobin S gene is inherited from only one parent and a normal hemoglobin gene-hemoglobin A-is inherited from the other.

Detailed explanation-5: -The abnormal shape of the cells in individuals with sickle cell anemia comes from a defective protein within the blood cells themselves. This defective protein is hemoglobin. The normal hemoglobin protein is made up of four parts, and therefore called a tetramer.