Consider the following statements : 1. Some microorganisms can grow in environments with temperature above the boiling point of water. 2. Some microorganisms can grow in environments with temperature below the freezing point of water. 3. Some microorganisms can grow in highly acidic environment with a pH below 3. How many of the above statements are correct?

States some microorganisms are found in extreme conditions such as hot water springs, showing microbes can tolerate much higher temperatures than typical environments.

Combine this with knowledge of higher-temperature habitats (e.g., geothermal or deep-sea sites) to suspect microbes might survive above 100°C in special settings.

Explains boiling point depends on ambient pressure (water can remain liquid at temperatures far above 100°C if pressure is high).

A student could apply this to high-pressure environments (e.g., deep ocean vents) to see where liquid water — and thus microbial growth — could occur above 100°C.

Notes that boiling point of water changes with salinity (higher salinity raises boiling point), giving another environmental parameter that affects liquid-water temperatures.

Use this with examples of salty geothermal waters to argue some locales could sustain liquid water above 100°C, potentially allowing thermotolerant microbes.

Describes variation in populations producing heat-resistant variants that can survive and grow when temperatures increase.

A student could infer that natural selection can produce microbial lineages adapted to very high temperatures, supporting the plausibility of organisms tolerating >100°C.

Defines microorganisms as ubiquitous (in water, soil, air, inside bodies), implying broad ecological ranges and potential for specialized extremophiles.

Combine ubiquity with knowledge of extreme habitats to justify searching for microbes in unconventional high-temperature niches.

States pH determines microbial proliferation and that most fungi prefer acidic environments, indicating some microbial groups tolerate/seek acidity.

A student could infer that if fungi favor acidic conditions, certain fungi (or acid-tolerant microbes) might persist even at very low pH and then check specialized literature or examples of acidophiles.

Notes that soils can be as low as pH 3, giving a natural setting where microbes would need to tolerate very low pH to live there.

A student can combine this with knowledge that microbes inhabit soils to suspect that some soil microorganisms must tolerate pH≈3 or lower and then look for documented acid-tolerant species.

Says acidic, poorly oxygenated wetlands are hostile to most microorganisms needed for decomposition, implying some microbes cannot survive extreme acidity while others (e.g., specialized ones) may persist.

A student could use this pattern to reason that while many microbes are excluded, a subset adapted to acidic, anaerobic conditions might remain — worth checking for known acidophiles in wetlands.

Bioremediation discussion highlights monitoring pH as a key factor controlling microbial activity, implying that pH limits which microbes can function in contaminated sites.

A student could extend this by considering engineered or natural sites with low pH and investigating whether specialized microbes are used or found there for degradation.

Defines acid soils (pH < 6) and lists chemical consequences, showing acidity is an environmental variable that shapes biological communities.

A student can extrapolate that stronger acidity (pH<3) would further filter microbial communities, motivating a search for taxa known to tolerate extreme acidity.