Select the correct combination of the statements (iiv) regarding the characteristics of certain organisms. (i) Methanogens are archaebacteria which produce methane in marshy areas. (ii) Nostoc is a filamentous bluegreen alga which fixes atmospheric nitrogen. (iii) Chemosynthetic autotrophic bacteria synthesize cellulose from glucose. (iv) Mycoplasma lack a cell wall and can survive without oxygen. The correct statements are

Explanation

The correct statements are (i), (ii), and (iv). Methanogens are indeed archaebacteria that produce methane, particularly in anaerobic environments like marshes. Nostoc is a filamentous cyanobacterium (often referred to as blue-green algae) that has the ability to fix atmospheric nitrogen. Mycoplasma are unique among bacteria in that they lack a cell wall, allowing them to survive in various environments, including oxygen-free conditions.On the other hand, statement (iii) is incorrect. Chemosynthetic autotrophic bacteria do not synthesize cellulose from glucose; rather, they utilize inorganic materials to produce energy and organic compounds. This fundamental misunderstanding disqualifies options A, B, and C from being correct.