Some hyperthermophilic organisms that grow in highly acidic $(pH \ 2)$ habitats belong to the two groups:

$Thiobacillus$ $ferrooxidans$ liberates energy by oxidizing:

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

Identify the bacteria given in the figure below.

The elementary cell body in $Mycoplasma$ performs the function of:

Cyanobacteria and heterotrophic bacteria have been clubbed together in eubacteria of kingdom-Monera as per the "five kingdom classification", even though the two are vastly different from each other. Is this grouping of the two types of taxa in the same kingdom justified? If so, why? Discuss the cellular composition of cyanobacteria and heterotrophic bacteria that make them classified as eubacteria.