The organisms responsible for the production of methane are ......... .

Which one of the following statements about mycoplasma is wrong?

What type of nutrition is exhibited by organisms of the Kingdom Monera?

Which of the following is responsible for the production of methane?

In $Aulosira$,$Tolypothrix$ and $Nostoc$, . . . . . . are the sites for Nitrogen fixation.

Refer to the given figures of a bacterial cell and Nostoc and choose the option which shows the correct labels for the structures marked as $A$,$B$,$C$,$D$,and $E$.