Exam 10: The Integration of Genetic Approaches: Understanding Sickle Cell Disease

The same DNA probe used to measure mRNA levels by northern blotting can also be used on a Southern blot with a restriction digest of genomic DNA.What new information can be gained from Southern blotting (that wasn't already obtained by the northern blot analysis)?

You have digested a molecule of DNA and want to identify a specific fragment of interest.The DNA is subjected to gel electrophoresis,but you get two bands that are very close in size.What could you use to determine which band is the correct one?

Ingram examined hemoglobin structural variation by breaking down the hemoglobin protein into many fragments by chemical treatment and subjecting the fragments to electrophoresis to separate them in a gel;and then in a second dimension,perpendicular to the first,he separated them by chromatography.This two-step approach is commonly referred to as

Which of the following images represents the expected results of a DNA gel for three individuals with different genotypeshomozygous dominant,heterozygote,and homozygous recessive?

Hemoglobin is made up of four proteins from two different gene clusters,the α-globin gene cluster and the β-globin gene cluster.The two clusters are related,having evolved from a common ancestral gene through gene duplication,based on strong similarities in which three gene characteristics?

A couple has four children;one is affected by SCD,and two are carriers of the disease.What can be said of the genotypes of the parents?

The intercalating agent ________ allows researchers to visualize DNA and RNA on a gel when the gel is exposed to UV light.

Given the following Southern blot results,which lane represents a heterozygous individual?

What term is used to describe the situation when the loss of an allele because of selection against one of its phenotypes is balanced by natural selection in favor of the allele for another phenotype?

The different globin genes in each cluster are sequentially expressed in tightly controlled patterns during the various stages of prenatal and adult development.What gene structure helps regulate globin gene transcription by controlling both the timing and the starting point for transcribing DNA into mRNA?

Burkitt's lymphoma is a cancer of the lymphatic system.The endemic variant,common to equatorial Africa,commonly affects children who are also affected by chronic malaria.A recent study found that individuals with AA hemoglobin were twice as likely to develop Burkitt's lymphoma as those with the AS genotype.We saw a similar benefit of certain genotypes in cases of sickle cell disease.Recall that individuals who are βᴬβˢ,βᴬβᶜ,or βᴬβᴱ have a survival and reproductive advantage over individuals who are homozygous βᴬβᴬ (and therefore succumb more easily to malaria)and over those who are homozygous for the mutant alleles (and therefore suffer from hereditary anemia).Resistance to malaria and Burkitt's lymphoma are both an example of ________ advantage.

The rate of molecule movement in electrophoretic gels depends on three parameters of molecular structure.Each of these parameters individually is important in determining how a particular molecule migrates,but they can also interact with one another to produce a characteristic migration rate for each molecule.What are the three parameters?

How is the DNA visualized on a Southern blot?

Given what you know of the inheritance pattern of SCD,what can be said of individual II-5?

Given the following gel,which protein is more likely to have a globular shape?

As part of the maturation process,red blood cells lose their nucleus.What is the consequence for cell division in these cells?

Thalassemia is a recessive blood disease caused by reduced synthesis of one of the globin genes.While SCD is a mutation in the structure of hemoglobin,thalassemias can also be caused by mutations in the regulatory elements,causing too little globin to be produced and resulting in anemia.You've designed a DNA probe that you want to use to screen a family for a rare mutation in the β-globin gene that causes thalassemia.First you will use the probe for northern blotting.What information will the northern blot tell you?

Given the following plasmid,what are the sizes of the fragments you would expect from an XhoI digest?

You set up an EcoRI restriction digest for a sample of genomic DNA from an individual with a hemoglobin mutation.To your surprise,you notice a different pattern of bands in the affected individualyou have identified a new SNP! What can you conclude from the pattern of bands from the gel below?

Given the following plasmid,what are the sizes of the fragments you would expect from a NotI digest?