Which of the following statements is not true for Nostoc?
Select the correct combination of the statements (1-4) regarding the characteristics of certain organisms 1. Methanogens are archaebacteria which produce methane in marshy areas 2. Nostoc is a filamentous blue-green alga which fixes atmospheric nitrogen 3. Chemosynthetic autotrophic bacteria synthesize cellulose from glucose. 4. Mycoplasma lacks a cell wall and can survive without oxygen. The correct statements are: