Which type of cell division occurs in $Nostoc$?

Provide the full forms of the following abbreviations:
$(i)$ $PPLO$
$(ii)$ $RNA$

Write a short note on Archaebacteria.

Which are the most primitive types of organisms?

Mycoplasma is a:

The nucleotide sequence in ribosomal $RNA$ provides the best evidence for the phylogeny of Monera. Based on this information,which are the most primitive Monerans?