Exam 20: Dna Tools and Biotechnology

Use the following information to answer the next few questions. Pharmacogenetics is an increasingly important discipline that uses genetic information to tailor the prescription of drug treatments to individuals. In the case of chemotherapy for breast cancer, for example, different patients need and/or respond to different treatments. -Patients whose tumours are HER-2 positive respond to herceptin whereas other patients do not. Patients whose tumours have estrogen receptors will be best served if

-The segment of DNA shown in the figure above has restriction sites I and II, which create restriction fragments A, B, and C. Which of the gels produced by electrophoresis shown below best represents the separation and identity of these fragments?

Which of the following best describes the complete sequence of steps occurring during every cycle of PCR? 1. The primers hybridize to the target DNA. 2. The mixture is heated to a high temperature to denature the double-stranded target DNA. 3. Fresh DNA polymerase is added. 4. DNA polymerase extends the primers to make a copy of the target DNA.

In order to identify a specific restriction fragment using a probe, what must be done?

Why are yeast cells frequently used as hosts for cloning?

How difficult is it to clone a plant?

A researcher is using adult stem cells and comparing them to other adult cells from the same tissue. Which of the following is a likely finding?

Modern forensic investigation uses ________ to identify criminals.

In animals, what is the difference between reproductive cloning and therapeutic cloning?

In large-scale, genome-wide association studies in humans, correlation is sought between

Use the following information to answer the questions below. Spider silk is one of the strongest biomolecules known. It has a tensile strength greater than Kevlar and elasticity greater than rubber. Attempts to "farm" spiders have met with little success (they tend to eat each other). Researchers have identified the gene responsible for the formation of the silk. -What would be a plausible suggestion to produce this protein for human use?

Which of the following is used to make complementary DNA (cDNA)from RNA?

In animals, embryonic stem cells differ from adult stem cells in that

In 1997, Dolly the sheep was cloned. Which of the following processes was used?

A linear piece of viral DNA of 8000 base pairs in length (8kb)can be cut with either of two restriction enzymes (X or Y). These are subjected to electrophoresis and produce the following bands: Cutting the same 8 kb piece with both enzymes together results in bands at 4.0, 2.5, 1.0, and 0.5. Of the possible arrangements of the sites given below, which one is most likely?

Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme?

Use the following information to answer the next few questions. CML (chronic myelogenous leukemia) results from a translocation between human chromosomes 9 and 22. The resulting chromosome 22 is significantly shorter than usual, and it is known as a Philadelphia (Ph') chromosome. The junction at the site of the translocation causes overexpression of a thymine kinase receptor. A new drug (Gleevec or imatinib) has been found to inhibit the disease if the patient is treated early. -Why would Gleevec most probably cause remission of the disease?

Use the following information to answer the next few questions. A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI. The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline. The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene. This mixture is incubated for several hours, exposed to DNA ligase, and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth without antibiotics. -Bacteria containing a plasmid into which the eukaryotic gene has integrated would grow in

Why is it so important to be able to amplify DNA fragments when studying genes?

Expression of a cloned eukaryotic gene in a bacterial cell involves many challenges. The use of mRNA and reverse transcriptase is part of a strategy to solve the problem of