What types of genetic transitions are there?
Genetic Transitions are mutations on genes or in a DNA sequence. Point mutations are the most frequent of transitions.
What are point mutations and where do they occur?
Point mutations come about because of errors in the synthesis of DNA or from errors in the repair of a strand of DNA on a chromosome. These errors occur from substituting on purine for a pyrimidine or vice versa. A purine is the adenine or guanine in DNA and a pyrimindine is thymine or cytosine. These errors occur during the replication of DNA.
If point mutations occur, what is an example?
An example of a point mutation is the disease sickle cell anemia. Sickle cell anemia is when the hemoglobin in the red blood cells becomes deformed into the shape of a sickle. The sickle shape of the cell, compared to the normal round shape, causes the hemoglobin to build up in the capillaries where the pathway is too narrow for the deformed cell. The back-up of the cells reduces oxygen flow to certain muscles and causes extreme pain. Sickle cells form due to a point mutation where a nucleotide of the DNA is changed from adenine to thymine, or cytosine to guanine within an amino acid. When this occurs, the hemoglobin protien is changed and a misshaped hemoglobin becomes present in those with sickle cell disease.
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This
cell is an example of a normal red blood cell.
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This
cell has a mishapen hemoglobin causing a sickle shaped red blood
cell.
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Is Sickle Cell Anemia a) incorrect inscription of DNA or b) a product of the cell being too large to pass through a vessel?
True or False: Point Mutations occur when there is an error in the DNA synthesis or when a strand of DNA is unable to repair itself.
Created By: Chelsea K. Lattas