The existence of the process of transformation in cyanobacteria has been experimentally established by

Which group of organisms is both $CO_2$-fixing and $N_2$-fixing?

Which of the following statements is correct?

Which kingdom incorporates photoautotrophs,chemoautotrophs and heterotrophs?

Read the following statements:
$A.$ Mango is included under order 'Poales'.
$B.$ Chemosynthetic autotrophic bacteria oxidize various inorganic substances such as nitrite and ammonia and use the released energy for their $ATP$ production.
$C.$ Members of Ascomycetes are parasitic only.
$D.$ In one citric acid cycle,$2 NADH_2$ and $1 FADH_2$ are formed.
$E.$ Pyruvic acid $+ CoA + NAD^+ \xrightarrow{\text{Pyruvate dehydrogenase}} \text{Acetyl } CoA + CO_2 + NADH + H^+$.
Choose the correct option:

The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals include .......