mi Pretest (baseline)

Your starting point for the semester. Enter your Student ID and answer each item. This is a growth check against the WebXam blueprint, not a grade.

1. 1. The main purpose of PCR is to:

   AMake many copies of a target DNA regionBCut DNA at specific sitesCRead a protein sequenceDKill bacteria

2. 2. On a DNA gel, the fragments that travel farthest are the:

   ASmallest fragmentsBLargest fragmentsCMost charged proteinsDHeaviest cells

3. 3. A BLAST hit with an E-value of 1e-50 versus one of 5.0 is:

   AA much stronger match (smaller E-value)BA weaker matchCExactly the sameDNot comparable

4. 4. An ELISA that calls a healthy person positive has produced a:

   AFalse positiveBFalse negativeCTrue positiveDTrue negative

5. 5. A restriction enzyme is used to:

   ACut DNA at a specific recognition sequenceBJoin DNA fragmentsCCopy DNADStain DNA

6. 6. A bright spot on a gene-expression microarray means that gene is:

   AHighly expressed in the sampleBDeletedCA proteinDUnrelated to expression

7. 7. In gene therapy, a viral vector is used to:

   ADeliver a working gene into cellsBGive the patient a diseaseCRemove all DNADSequence the genome

8. 8. A key safety concern with CRISPR editing is:

   AOff-target edits at unintended sitesBIt cannot cut DNACIt only works in plantsDIt adds antibiotics

9. 9. A SNP is a:

   ASingle-base difference at one positionBMissing chromosomeCProteinDAntibody

10. 10. To make human insulin in bacteria, you first:

    AInsert the human insulin gene into a plasmidBInject bacteria into the patientCRemove all bacterial DNADSequence the patient

11. 11. A tumor suppressor gene normally:

    ARestrains cell divisionBSpeeds uncontrolled divisionCMakes antibodiesDDigests food

12. 12. Leaving a culture plate uncovered on the bench most likely causes:

    AAirborne contaminationBFaster correct resultsCSterilizationDNo change

13. 13. One bacterial colony on a plate grew from:

    AA single founding cell (CFU)BMany unrelated speciesCA virusDThe agar

14. 14. A larger clear zone around an antibiotic disk means the bacteria are:

    AMore susceptible to itBMore resistant to itCUnaffectedDContaminated

15. 15. Resistance genes spread quickly between bacteria mainly via:

    APlasmids by horizontal transferBSunlightCDietDVaccination

16. 16. Before handling a new reagent, you should first check its:

    ASafety Data Sheet (SDS)BPriceCColor onlyDBrand popularity

17. 17. Three sequential 1:10 dilutions give a final dilution of:

    A1:1000B1:30C1:300D1:100

18. 18. "The disease will likely progress over years" is a:

    APrognosisBDiagnosisCSymptomDLab value

19. 19. An outbreak line list has one row per:

    ACase, with onset, symptoms, and exposuresBCityCReagentDUnrelated disease

20. 20. Herd immunity protects unvaccinated people because:

    AToo few susceptible hosts remain for spreadBThe vaccine spreads through airCEveryone must be vaccinated for any effectDIt cures current disease

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