MI CFA: Unit 1 — Fight Infection

A short unit check. Enter your Student ID and answer each item. This is a growth check, not a grade.

1. 1. Before handling a patient blood sample, which step protects both you and the sample first?

   APut on gloves and eye protection, then label the tubeBSmell the sample to identify itCPipette by mouth for accuracyDSkip PPE if you work quickly

2. 2. Which item belongs as one row on an outbreak line list?

   AOne case with onset date, symptoms, and exposuresBThe total population of the cityCThe lab's reagent inventoryDA list of unrelated diseases

3. 3. Two BLAST hits both align to your unknown sequence. Hit 1 has 99% identity and an E-value of 2.0. Hit 2 has 88% identity and an E-value of 1e-40. Which is the stronger match, and why?

   AHit 1, because percent identity is highestBHit 2, because the much smaller E-value means the alignment is far less likely by chanceCHit 1, because a higher E-value is betterDThey are equally good matches

4. 4. You make a 1:10 dilution, then dilute that 1:10 again, then 1:10 once more. The final dilution is:

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

5. 5. An ELISA reports a patient as positive, but the patient does not actually have the disease. Which term names this result?

   AFalse positiveBLow sensitivityCTrue negativeDLow specificity is impossible here

6. 6. On an ELISA plate, the negative control well develops a strong color signal. What does this most likely indicate?

   AThe assay worked correctlyBContamination or nonspecific binding invalidated the runCEvery patient sample is positiveDThe primary antibody was too dilute

7. 7. On a disk-diffusion plate, a larger clear zone around an antibiotic disk indicates that the bacteria are:

   AMore susceptible to that antibioticBMore resistant to that antibioticCUnaffected by itDContaminated

8. 8. Leaving a culture plate's lid off on the open bench most likely causes:

   AAirborne contamination of the plateBFaster correct resultsCSterilization of the plateDNo change at all

9. 9. On an audiogram, a threshold plotted lower on the chart (more dB needed to hear a tone) means:

   AWorse hearing at that frequencyBBetter hearing at that frequencyCPerfect hearingDThe test failed

Enter your Student ID to submit.