Endospores formed by certain bacteria are actually the means for

Match the following:

Column-$I$ (Group of bacteria)	Column-$II$ (Their shape)
$a.$ Coccus	$(i)$ Rod-shaped
$b.$ Bacillus	$(ii)$ Spherical
$c.$ Spirillum	$(iii)$ Spiral
$d.$ Vibrio	$(iv)$ Comma-shaped

Cyanophyceae (Blue-green algae) is characterized by the presence of:

In the light of the recent classification of living organisms into three domains of life ($Bacteria$,$Archaea$,and $Eukarya$),which one of the following statements is true about $Archaea$?

Assertion $A$: Some bacteria possess unique phenotypic characters.
Reason $R$: Many bacterial cells contain plasmid $DNA$ in addition to genomic $DNA$.
Which option is correct for Assertion $A$ and Reason $R$?

Cyanobacteria are