Chapter 18, Problem 40CI

Thalassemia is an inherited genetic mutation that limits the production of the beta Chain needed for the formation of hemoglobin. If low levels of the beta chain are produced, There is shortage of red blood cells (anemia); as a result, the body does not have sufficient Amounts of oxygen. In one form of thalassemia,a single nucleotide is deleted in the DNA that codes for the beta chain. The mutation involves the deletion of thymine (T) from section 91 in the informational strand of normal DNA. (16.2, 17.3, 17.4, 17.5, 17.6)

89	90	91		92		93	94	95
-AGT	GAG	CTG		CAC		TGT	GAC	A.

1. Write the complementary (strand) for the normal DNA segment.
2. Write the mRNA sequence from normal DNA using the template strand in part a.
3. What amino acids are placed in the beta chain by this portion of mRNA?
4. What is the order of nucleotides in the mutated DNA segment?
5. Write the template strand for the mutated DNA segment.
6. Write the mRNA sequence from the mutated DNA segment, using the template strand
In part e.
7. What amino acids are placed in the beta chain by the mutated DNA segment?
8. What type of mutation occurs in this form of thalassemia?
9. How might the properties of this section of beta chain be different from the
Properties of the normal protein?

10. How might the level of structure in hemoglobin be affected if beta chains are not produced?