Question

Select the correct statements w.r.t. characteristics of certain organisms.
(a) Methanogens are archaebacteria which produce methane in marshy areas.
(b) Nostoc is a filamentous green algae which fixes atmospheric nitrogen.
(c) Chemosynthetic autotrophic bacteria synthesize cellulose from glucose.
(d) Mycoplasma lacks a cell wall and can survive without oxygen.

Answer 1

Methanogens are archaebacteria that produce methane as a metabolic byproduct in anoxic conditions. They are obligate anaerobic ancient and primitive bacteria.
Nostoc is not a green algae, it is blue-green algae or cyanobacteria.
Chemosynthetic autotrophic bacteria oxidizes inorganic substances such as nitrates, nitrites and ammonia and use the released energy for their ATP production.
Mycoplasma are the smallest, prokaryotes and lack a cell wall. They have the ability to survive without oxygen.