In separating DNA for genomic analysis, evaluate the potential consequences of RNA contaminating the sample during the cell lysis step. What are these consequences, and what consideration should be made, if any, in adjusting the technique?
DNA separates into the supernatant; no corrective action needed.
DNA is destroyed by the protease; RNA and DNA must be isolated during the cell lysis step.
DNA is unaffected by the RNA; no corrective action needed.
DNA combines with the RNA; RNA and DNA must be isolated during the cell lysis step.
45.
There are many techniques for investigating human genomic disorders. Western blotting looks for protein, Eastern blotting looks for post-translational changes, Northern blotting looks at mRNA, and Southern blotting looks at DNA. Compare these differences to answer the following: If you were to look at sickle cell anemia, a disorder affecting hemoglobin produced in red blood cells, which technique would be the most useful in detecting polymorphism in a sample?
Northern blotting
Southern blotting
Western blotting
Eastern blotting
46.
A population of insects was formally distinguished by a mix of colors on their thorax and legs. This population appeared to split over time into two sub-groups, purple-legged and orange-legged. Researchers hypothesize that the purple-legged group may be increasingly resistant to the Bt (Bacillus thuringiensis) toxin. Which biological process supports their claim?
transgenesis
natural selection
hybridization
recombination
47.
Rather than producing an exact copy of an existing organism--how we typically think of cloning--molecular cloning reproduces exact, selected genome fragments. Evaluate the descriptions of the mechanisms involved in the process of molecular cloning and select the most accurate summary.
The foreign DNA and plasmid are cut with the same restriction enzyme and DNA is inserted within the lacZ gene, whose product metabolizes lactose. The foreign DNA and vector are allowed to anneal. The vector is transferred to a bacterial host that is ampicillin sensitive and those with a disrupted lacZ gene show inability to metabolize X-gal.
The foreign DNA and plasmid are denatured using high heat, and DNA is inserted within the lacZ gene, whose product metabolizes glucose. The foreign DNA and vector are allowed to anneal. The vector is transferred to a bacterial host that is ampicillin sensitive and disrupted lacZ gene will metabolize X-gal
The foreign DNA and plasmid are cut with the same restriction enzyme and DNA is inserted randomly in the plasmid. The foreign DNA and vector are allowed to anneal. The vector is transferred to a bacterial host that is ampicillin sensitive and the disrupted lacZ gene shows inability to synthesize X-gal.
The foreign DNA and plasmid are cut with the same restriction enzyme and DNA is inserted within the lacZ gene, whose product metabolizes lactose. The foreign DNA and vector are allowed to anneal. The vector is transformed into a viral host that is ampicillin sensitive and the disrupted lacZ gene show inability to synthesize X-gal.
There are three methods of creating maps to evaluate genomes: cytogenetic mapping (staining chromosomes), which is pictured; radiation hybrid mapping (fragments with x-rays); and sequence mapping (comparing DNA sequences). Compare the different approaches each takes. Which of the following statement accurately describes the three methods and highlights their differences?
Cytogenetic mapping - stained sections of chromosomes are analyzed using microscope, the distance between genetic markers can be found; Radiation hybrid mapping - breaks DNA using radiation and is affected by recombination frequency; Sequence mapping - DNA sequencing technology is used to create physical maps.
Cytogenetic mapping - stained sections of chromosomes are analyzed using microscope, the approximate distance between genetic markers can be found; Radiation hybrid mapping - breaks DNA using radiation and is unaffected by recombination frequency; Sequence mapping - DNA sequencing technology is used to create physical maps.
Cytogenetic mapping - stained sections of chromosomes are analyzed using microscope, the distance in base pairs between genetic markers can be found; Radiation hybrid mapping - breaks DNA using radiation and is unaffected by recombination frequency; Sequence mapping - DNA sequencing technology is used to create physical maps.
Cytogenetic mapping - stained sections of chromosomes are analyzed using a telescope, the distance between genetic markers can be found; Radiation hybrid mapping - breaks DNA using radiation and is affected by recombination frequency; Sequence mapping - DNA sequencing technology is used to create physical maps.
49.
(credit: modification of work by Genome Research)
The image shows a map of the human X and Y chromosomes. To get this map, the chromosome was broken into smaller pieces using x-rays.
