A researcher studying bacterial toxin predicts that a lysine within the toxin is important for binding it’s target cell.  She used site-directed mutagenesis to change a codon for lysine (AAA) to one for asparagine (AAU).  However, the mutant toxin still binds to its target cell just as well as the wild-type toxin bound and appears to have no other changes. This type of mutation is probably

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#Question id: 10961

#I Life Science/ Life Sciences Group – I-V

Over the past 12 weeks, a 75-year-old man with a moderate aortic stenosis has developed shortness of breath and chest pains during exertion. He appears pale. Test of his stool for blood is positive. Laboratory studies show the following: hemoglobin 7.2 g/dL, and mean corpuscular volume 75. A blood smear shows microcytic, hypochromic erythrocytes. Which of the following is the most likely diagnosis?

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#Question id: 1292

#SCPH06 I Botany

Heparan sulfate, an example of a(n) _____________, aids in the activation of ____________.

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#Question id: 4321

#SCPH28 | Zoology

A genetic test to detect predisposition to cancer would likely examine the APC gene for involvement in which type(s) of cancer?

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#Question id: 10952

#I Life Science/ Life Sciences Group – I-V

Which of the following blood units carries the least risks for inducing an immediate transfusion reaction into a B+ (B, rhesus positive) recipient?

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#Question id: 12911

#SCPH28 | Zoology

Match the following:

A. DNA polymerases              i. Alkaline phosphatase        a.RNA-dependent DNA polymerase, used in cDNA synthesis

B. Reverse transcriptase        ii. T4 DNA ligase                    b. Thermostable DNA polymerase used in PCR

C. Ligases                                 iii.  AMV-RT                            c. Removes 5′-phosphates from DNA and RNA

D. Phosphatases                     iv. Taq DNA pol                      d. Links 5′-phosphate and 3′-hydroxyl ends via phosphodiester bond