In the five kingdom system of classification,which single kingdom out of the following can include blue-green algae,nitrogen-fixing bacteria,and methanogenic archaebacteria?

Consider the following four statements $(A-D)$ and select the option which includes all the correct ones only.
$(A)$ Archaebacteria differ from other bacteria in having a different cell wall structure.
$(B)$ Bacteria as a group show the most extensive metabolic diversity.
$(C)$ All Eubacteria have chlorophyll ' $a$' pigment similar to green plants.
$(D)$ Mycoplasma can survive without oxygen.

In which kingdom are prokaryotes included?

Select the mismatched pair from the following.

The bacterial genome refers to the total number of genes located upon a

$A$: Some bacteria are Gram-negative.
$R$: Gram-negative bacteria do not retain the Gram stain.