Unit 5: Quality Assurance of Biopesticides - Practice Quiz

1 Which quality assurance parameter confirms that a microbial biopesticide contains the intended microorganism?

2 What does the viable count of a microbial biopesticide indicate?

3 Which parameter is commonly expressed as colony-forming units per gram or milliliter?

4 Why is contamination checked in a microbial biopesticide?

5 What does the shelf life of a microbial biopesticide describe?

6 Which parameter measures how acidic or alkaline a microbial biopesticide formulation is?

7 Why is moisture content monitored in a dry microbial biopesticide formulation?

8 Which quality parameter shows whether a microbial biopesticide can control its target pest or pathogen?

9 What is the main purpose of checking the purity of a microbial biopesticide culture?

10 Which information should appear on a microbial biopesticide label for proper quality assurance?

11 Which procedure is commonly used to estimate viable bacterial or fungal counts in a formulation?

12 What is the main purpose of taking a representative sample from a biopesticide batch?

13 Which instrument is normally used to measure the pH of a liquid microbial biopesticide?

14 Why are microbial cultures examined under a microscope during quality control?

15 What is tested in a bioassay of a microbial biopesticide?

16 What should be done when a microbial biopesticide batch fails to meet an established quality standard?

17 Why are storage stability tests conducted on microbial biopesticides?

18 Which quality control step helps trace a microbial biopesticide back to its production history?

19 Why is the integrity of a microbial biopesticide container inspected?

20 What is the purpose of calibrating equipment used in quality control testing?

21 A microbial biopesticide retains the correct organism identity and has no detectable contaminants, but its viable count is below the product specification. Which quality parameter has failed?

22 Two batches of a fungal biopesticide have the same spore concentration. Batch X has 92% spore germination, while Batch Y has 55% germination. Which conclusion is most appropriate?

23 A wettable powder forms persistent clumps and settles rapidly after mixing with water. Which quality parameters should be examined first?

24 A bacterial biopesticide is stored under humid conditions, and its moisture content rises above specification. What is the most likely quality risk?

25 A product contains the required number of viable cells but provides poor disease suppression in a standardized assay. Which additional parameter is most directly in question?

26 Why is strain-level identity important when assuring the quality of a microbial biopesticide?

27 A product meets its viable-count specification when manufactured but falls below the limit three months before its labeled expiry date. Which quality assurance parameter was inadequately established?

28 A liquid microbial formulation changes from pH 6.5 to pH 4.0 during storage. Why should this change be investigated?

29 A microbial biopesticide container allows moisture to enter during storage. Which paired quality attributes are most likely to be affected?

30 Why is contaminant level assessed separately from viable count in a microbial biopesticide?

31 A technician plates 0.1 mL of a dilution and counts 84 colonies. What is the estimated viable count in the original sample?

32 Plate counts from duplicate samples of the same batch differ by more than 100-fold. What should the laboratory do first?

33 Which procedure best provides representative samples from a large batch of microbial biopesticide?

34 Microscopic examination suggests that a fungal biopesticide contains the expected species, but strain identity remains uncertain. Which method is most suitable for confirmation?

35 During a contamination test, colonies with unexpected morphology appear on nonselective medium. What is the most appropriate next action?

36 A laboratory is validating a bioassay for a microbial insecticide. Why should an untreated control be included?

37 Before measuring the pH of several liquid biopesticide batches, which action is essential for reliable results?

38 An accelerated storage test shows rapid loss of viability at elevated temperature. How should this result be used?

39 A batch passes viable-count and purity tests but fails the standardized efficacy bioassay. What is the appropriate release decision?

40 Why are retained samples from each production batch stored under defined conditions?

41 A liquid microbial biopesticide is diluted to , and of that dilution produces 84 colonies. Assuming every viable propagule forms one colony and dilution error is negligible, what is the estimated viable count in the original product?

42 A fungal biopesticide has an initial count of and must remain above through expiry. What is the maximum allowable reduction, expressed as a base-10 logarithmic loss?

43 Two dry conidial formulations have identical moisture contents, but batch X loses viability much faster than batch Y. Which additional parameter most directly assesses the availability of water for degradative and microbial processes?

44 A bacterial biopesticide strain differs from a non-active environmental strain by a small genomic region that is absent from standard 16S rRNA reference sequences. Which identity specification is most appropriate for routine release?

45 A batch meets its viable-count specification but repeatedly gives low insect mortality in a standardized bioassay. Which interpretation best explains the discrepancy?

46 Microscopy shows conidia per gram, while plate counting shows . If each colony is assumed to originate from one conidium, what is the apparent germinable fraction?

47 A wettable powder passes viable-count and contamination limits but forms persistent sediment that cannot be redispersed at the labeled application rate. Which quality parameter has most directly failed?

48 A minimum potency specification is . A batch result is with an expanded uncertainty of . Under a decision rule requiring the entire uncertainty interval to exceed the minimum, what is the correct disposition?

49 During storage, CFU remain within specification but particle size increases and nozzle blockage occurs. Which paired parameters would have provided the most relevant early warning?

50 An accelerated study at predicts a 24-month shelf life at using an Arrhenius model, but the formulation undergoes phase separation only below . What is the strongest quality-assurance conclusion?

51 For a contamination test, 10 g of product is homogenized in 90 mL diluent and is plated without further dilution. No colonies are observed. What is the method's nominal detection limit in the original product?

52 A powdered product may develop localized contaminant pockets near a filling hopper. Which sampling design is most likely to detect this non-uniform contamination?

53 A preservative in a formulation suppresses recovery of both the active microorganism and a spiked contaminant during plate counting. What should be established before using the method for release testing?

54 A qPCR identity assay reports a strong target signal in a heat-inactivated batch, while culture shows no viable active organism. Which procedural conclusion is most appropriate?

55 A mixed microbial product contains two morphologically similar strains, but release specifications require separate viable counts for each strain. Which procedure is most defensible?

56 Eight consecutive production batches remain within specification, but viable counts decrease monotonically toward the lower limit. What is the most appropriate quality-control response?

57 An initial potency result is below specification. Two repeat preparations pass, and the analyst proposes averaging all three results to release the batch. Which action best follows sound out-of-specification practice?

58 Replicate plate counts from a conidial suspension are reproducible but consistently lower than direct counts because conidia remain in clusters. Which validation experiment most directly addresses the bias?

59 A target-insect bioassay is used for lot release, but mortality in the untreated control varies substantially among test runs. Which procedural change most improves comparability of potency results?

60 A sterility control remains negative, the positive growth control performs normally, but recovery from product-spiked samples is only 15%. What is the correct interpretation of the contamination test?