Question

Genes are unique segements of A, T, C, and G sequences in our DNA. Each piece of our DNA contains many genes. The 46 human chromosomes contain around 20,000 genes. Gene 2 DNA molecule Linus Pauling's research was centered on the the function of one particular gene, the HBB gene. His data indicated that the cell uses the information in the HBB gene as a "recipe" to construct hemoglobin. The hemoglobin recipe in normal individuals was accurate so their cells were able to make normal hemoglobin. In individuals with sickle cell, a change in the HBB gene (a mutation) caused the cells to make hemoglobin incorrectly resulting in the dysfunctional sickle shape. The mutation in the HBB gene resulted in a change the 7th amino acid in sickled hemoglobin. The figure below shows the difference between the DNA sequence in the normal HBB gene and the the DNA sequence in the mutated HBB gene. A singular difference in the DNA like this is point mutation. Normal hemoglobin DNA Mutant hemoglobin DNA MTW MTWTTI Choose the TWO correct answers the DNA sequence in the normal hemoglobin gene is CTT the DNA sequence in the normal hemoglobin gene is CAT there are many differences between the DNA sequence in the normal hemoglobin gene and the DNA sequence in the mutated hemoglobin gene there is one difference between the DNA sequence in the normal hemoglobin gene and the DNA sequence in the mutated hemoglobin gene

Answer 1

The two correct answers are

1.The DNA sequence in the normal haemoglobin gene is CTT.

2.There is one difference between the DNA sequence in the normal haemoglobin gene and the DNA sequence in the mutated haemoglobin gene.

Point mutation involves single nucleotide base change. This change can be of different kinds. Ex. Silent, missense or nonsense ( stop).