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Practice Environmental Responses, Quorum Sensing and Biofilms - Microbial Growth - Life Sciences previous year questions organised from real papers, with year-wise coverage and clear topic navigation.
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Year-wise coverage for Environmental Responses, Quorum Sensing and Biofilms. Each bar uses a separate theme-derived color.
How the classified questions are distributed by difficulty.
MCQ, numerical, multiple-select and other formats found in these papers.
Top subjects by unique question coverage.
Top topics across the included previous year papers.
Top subtopics inside this exact selection.
Question coverage for the most populated papers. Every active PYP paper remains listed below.
Newest papers appear first. Sort by year, question coverage or name.
| Paper | Year / session | Questions in this view | Open |
|---|---|---|---|
| Life Sciences (XL) 2026 | 2026 | 1 | View paper |
| Life Sciences (XL) 2025 | 2025 | 2 | View paper |
| Life Sciences (XL) 2023 | 2023 | 1 | View paper |
| Life Sciences (XL) 2017 | 2017 | 1 | View paper |
| Life Sciences (XL) 2014 | 2014 | 1 | View paper |
| Life Sciences (XL) 2011 | 2011 | 1 | View paper |
| Life Sciences (XL) 2007 | 2007 | 1 | View paper |
Practice every matching question in batches of 20, with every available option.
Which group of microorganisms have a high level of unsaturated fatty acids in their cell membrane?
Determine the correctness or otherwise of the following Assertion [a] and the Reason [r].
Assertion [a]: Endospore can survive heat that would rapidly kill vegetative cells of the same species.
Reason [r]: In endospore, the protoplasm is reduced to minimum volume as a result of the accumulation of calcium-dipicolinic acid complexes and small acid-soluble spore proteins, which forms a cytoplasmic gel and a thick cortex.
Correctly match the bacterial type in Column I with their corresponding environmental niche in Column II.
| Column I | Column II |
|---|---|
| P. Psychrophile | i. Pressure greater than 380 atm |
| Q. Barophile | ii. Temperature between 15°C and 45°C |
| R. Mesophile | iii. Temperature below 15°C |
| S. Halophile | iv. pH less than 3.0 |
| v. Salt concentration greater than 2M |
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)?
Which one of the following molecules is the master regulator of the planktonic-
surface transition in Pseudomonas aeruginosa during biofilm formation?