Hormogonia of cyanobacteria are

Match Column-$I$ with Column-$II$ and choose the correct option given below:

Column-$I$ (Bacteria)	Column-$II$ (Shape)
$A$. Coccus	$iii$. Spherical
$B$. Bacillus	$i$. Rod-shaped
$C$. Vibrio	$iv$. Comma-shaped
$D$. Spirillum	$ii$. Spiral

Assertion $A$: Some bacteria are motile.
Reason $R$: Some bacteria have tubular pili or fimbriae extensions arising from their surface.
Which option is correct for Assertion $A$ and Reason $R$?

Which feature is common between methanogens and halophiles?

What is the primary function of a heterocyst in cyanobacteria?

What is the full form of $E. coli$?