4.3.2 Conclusion Questions

Erin is only seventeen years old and her total cholesterol is 600 mg/dL. Why do you think her cholesterol is so much higher than the others in her family who have familial hypercholesterolemia?

Even though Erin is much younger than her family members who suffer form hypercholesterolemia, her total cholesterol is so much higher than her relatives because her disease is worse. Unlike her family members who are heterozygous (Ff) for the disease, Erin is homozygous (FF). This allele different means that her form of hypercholesterolemia is much worse than those with only a Ff genotype, like her family members.

Explain how the use of Restriction Fragment Length Polymorphisms to diagnosis genetic disease differs from its use in forensic investigations.

In forensic investigations, Restriction Fragment Length Polymorphisms, or RFLPs, are used to compare genetic sequences, specifically that of fingerprints, to determine a unique DNA identification for each sample. However, in the diagnosis of genetic diseases, RFLPs are used to identify the alleles that cause diseases.

Why did the DNA migrate to the positive pole of the electrophoresis chamber? In your response, discuss the chemical structure of DNA.

The DNA migrated to the positive pole of the electrophoresis chamber because the chemical structure of DNA is negative, and since negative is attracted to positive, like poles on a magnet, it will move towards the positive end.

Explain how the class of medications called statins works to lower cholesterol levels in the body.

The class of medications called statins works to lower cholesterol levels in the blood by blocking the production of cholesterol in the body. This class of medications reduces the low-density lipoprotein (LDL) cholesterol and total cholesterol in the blood. Lower cholesterol levels help to prevent heart disease and plaque buildup in the arteries and help reduce the risk of heart attack and stroke.

Explain how you could determine which individuals were heterozygous by looking at the gel.

When looking at the gel, once it has run and the DNA has settled, either one or two bands will appear. Each band represents a different allele. By the definition of a heterozygous gene, two alleles must be present. Therefore, if one band, or one allele, can be seen in the gel, then the individual must be homozygous. Similarly, if two bands, or two alleles, can be seen in the gel, then the individual must be heterozygous.

Explain how you determined the genotype of Maria and Juanita, even though you did not test their DNA.

With the use of the genetic information provided by the gel, their genotypes can be determined. For Maria, since two of her children have a dominate FH gene, we know she must carry at least one of those. However, since her other child is homozygous recessive for FH, Maria has to have at least one recessive FH gene to pass on. Combining these two facts tells us that Maria's genotype is Ff. For Juanita, since her child is homozygous dominate for FH, Jaunita had to have passed on a dominant FH gene. In addition, since Jaunita's father is homozygous recessive for FH, he does not have a dominant FH gene to pass on, and therefore must of given her a recessive FH gene. Combining these two facts tells us that Jaunita's genotype, like Maria's, is Ff.