Life Sciences
GATE XL topic:microbial-growth PYQs
Build your understanding with focused practice from past exam papers.
How to practice topic:microbial-growth
Attempt a question, record the concept and assumptions, then check the available answer. Rework mistakes after revising the relevant concepts. Topic tags can overlap; review the question context.
Questions 1–10 of 25. Imported answers require independent review unless marked reviewed.
Question 69
Open questionXL-SMCQ1 markNeeds review
Which one of the following molecules is the master regulator of the planktonic-surface transition in Pseudomonas aeruginosa during biofilm formation?
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 73
Open questionXL-SNAT1 markNeeds review
The decimal reduction time of Escherichia coli at a particular temperature is one minute. Assuming no bacterial growth and constant death rate, the time required for one million bacteria to get reduced to one viable bacterium is ____ minutes. (Answer in integer)
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 70
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A penicillin sensitive Escherichia coli population is exposed to a lethal dose (200 μg/ml) of penicillin. Assuming density-independent mortality, which one of the following relationships would describe the number of surviving bacteria (N) over time (T)?
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 82
Open questionXL-SNAT2 marksNeeds review
At t = 0, the bacterial cell number is 10,000 cells/mL. At t = 480 minutes, the cell number increased to 320,000 cells/mL. The mean generation time during this exponential growth period, rounded off to the nearest integer is ______ minutes.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 83
Open questionXL-SNAT2 marksNeeds review
A landfill sample was analyzed by dilution and plate techniques for viable bacterial count. When one gram of the landfill sample was diluted 1 × 10⁻⁴ (w/v) it yielded 400 CFU. The viable bacterial count (in million, rounded off to the nearest integer) in one gram landfill sample is ______.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 69
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Microbial plastics are made from
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 73
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Which one of the following statements about batch culture of microbes is NOT correct?
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 84
Open questionXL-SNAT2 marksNeeds review
During the exponential growth, it took 6 hours for the population of bacterial cells to increase from 2.5 × 10⁶ to 5 × 10⁸. The generation time of the bacterium, rounded off to the nearest integer, is ______ minutes.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 80
Open questionXL-SMSQ2 marksNeeds review
Which of the following Gram-positive cocci are found in biofilm of dental plaque?
Your answerSelect all correct options. You can choose more than one.
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 83
Open questionXL-SNAT2 marksNeeds review
Escherichia coli growing under favorable conditions doubles in every 20 minutes. If the initial number of Escherichia coli cells is 100, what will be the logarithmic number of cells at 17th generation? (Answer up to 1 decimal place)
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