Magnesium ribonucleate is present in

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 $R$?

Identify the bacteria given in the figure below.

Most parasitic bacteria are ........

Which group of organisms is both $CO_2$-fixing and $N_2$-fixing?

Assertion: Bacteria have three basic shapes,i.e.,round,rod,spiral.
Reason: Cocci and Bacilli may form clusters or chains of a definite length.