There is no alternation of generation in $Escherichia$ $coli$ because there is no

Which group of Archaebacteria is found in extremely salty areas?

$A$ : Majority of bacteria are autotrophs.
$R$ : Chemoheterotrophic nutrition is absent in bacteria.

Which of the following antibiotics is found to be most effective against Mycoplasma?

What are episomes?

Select the correct statements from the given statements $(1-4)$ regarding the characteristics of some organisms.
$(1)$ Methanogens are Archaebacteria that produce methane in marshy areas.
$(2)$ $Nostoc$ is a flagellated blue-green alga that fixes atmospheric nitrogen.
$(3)$ Chemosynthetic autotrophic bacteria synthesize cellulose from glucose.
$(4)$ Mycoplasma lacks a cell wall and can survive without oxygen.