Purple sulphur bacteria are

Assertion $(S)$: Thermoacidophiles can survive in acidic and high-temperature conditions.
Reason $(R)$: Archaea can survive in extreme conditions.

$A$ bacterium is capable of withstanding extreme heat,dryness,and toxic chemicals. This indicates that it is probably able to form

The cell wall of halophilic bacteria is $NOT$ made up of which of the following?

The smallest known bacteria is:

The length of $Mycobacterium$ $tuberculosis$ is: (in $\mu m$)