The table given below lists types of extremophiles and the environments that they are adapted to.

	List I		List II
	Type of extremophile		Environment
A.	Psychrophile	I.	High salinity
B.	Hyperthermophile	II.	High pressure
C.	Alkaliphile	III.	High alkaline environment
D.	Hyperpiezophile	IV.	Extreme high temperature
E.	Halophile	V.	Extreme cold temperatures

Which one of the following options represents the correct match of the columns?

The correct answer is Option 3 i.e.A ‐ V, B ‐ IV, C ‐ III, D ‐ II, E ‐ I

Concept:

• Extremophiles are organisms that can survive and thrive under extreme geochemical and physical conditions. 
• Depending upon different extreme conditions, there are different types of extremophiles. 
• Extreme conditions included intense heat, high acidic, high alkalinity, high pressure, and extreme cold. 
• Mostly extremophiles are Archaebacteria, but some are even bacteria and Protista.
• All extremophiles are not unicellular, some are multicellular protosome animals.
• These organisms have evolved unique adaptations to survive in harsh environments.

Important Points

• Psychrophiles are cold-loving organisms that are able to survive and thrive under low temperature. Optimal growth temperature is about 15°C or below.
• Hyperthermophiles are heat-loving organisms that are able to thrive and survive under very high temperature of 80 to 110°C.
• Alkaliphiles are organisms that grow and reproduce under high alkali conditions, the pH values exceed 9.
• Hyperpiezophile are organisms that are able to survive under very high pressure of about 50MPa. 
• Halophiles are salt-loving organisms that are able to survive under high salt conditions.

Hence, the correct answer is Option 3.