Which organisms are responsible for the production of  biogas?

1. Archaebacteria
2. Eubactetia
3. Mycoplasma
4. Protists

The characteristic feature of eubacteria is -

1. Rigid cell wall
2. Flagellum in motile ones
3. Chlorophyll a
4. all of these

Cyanobacteria do not possess which feature?

1. Unicellular
2. Colonial or filamentous
3. Form blooms in polluted water bodies
4. Only marine algae

The specialised cells to fix atmospheric nitrogen is called as

1. Heterocyst
2. Heterocyte
3. Heterocoem
4. Heterolog

Find the incorrect match.

1. Heterocyst-Archaebacteria
2. Gelatinous sheath- BGA
3. Methanogen- Biogas
4. Chlorella- protista

Which of the following is correct with respect to heterocyst

1. Nostoc, Anabena
2. Only Anabena
3. Nostoc
4. All eubactetia

Chemosynthetic autotrophic bacteria does not help in recycling of

1. Nitrogen
2. Iron
3. Sulphur
4. Mangnese 

Chemosynthetic bacteria does not use which inorganic substrate?

1. Nitrites
2. Nitrates
3. Chlorides
4. Both a and b

Chemosynthetic autotrophs derive energy by

1. By sunlight
2. By oxidation of inorganic substances
3. By reduction of inorganic substances
4. By reduction followed by oxidation of inorganic substances

The majority of heterotrophic bacteria are

1. Decomposers
2. Autotrophs
3. Lithotrophs
4. Organotrophs