Question

Read the following statements regarding methanogens and select the correct option.
I. They are included in the group Archaebacteria.
II. They are responsible for the production of biogas in gobar gas plants.
III. They live in hot sulfur springs.
IV. They are strictly anaerobic.

A. Statement I and II are correct.
B. Statements I, II and IV are correct
C. Statements II, III and IV are correct.
D. All statements are correct.

Answer 1

Hint: Thermophiles, halophiles and methanogens are the three most important groups of living fossils. Methanogens that are found in marshy areas are responsible for the production of methane gas in the absence of oxygen.

Complete answer:
Archaebacteria belong to a group of unicellular prokaryotic organisms. Methanogens are formed from the bacteria known as Archaebacteria (also commonly called as the living fossils). In nature, these methanogens are found widely distributed. They have a characteristic structure of cell walls which makes them survive even under the extreme environmental conditions. Methanogens are often found in the gut of numerous ruminant animals like the buffaloes and the cows. Methane gas (also known as the biogas) is produced from the dung of these animals with the help of the methanogens only. This forms an important feature of methanogen. Moreover, they are strictly anaerobic in nature.
On the other hand, methanogens cannot survive in the hot springs as their growth is damaged in these hot springs.

So, the correct answer is option “B” that is the Statement I, II and IV are correct.

Note:
Methanogens have autotrophic mode of nutrition. They can obtain their own food as a source of carbon and energy from the dead and decay matter. In the marshy areas, methanogens are responsible for the conversion of carbon dioxide and formic acid into the methane gas in the presence of hydrogen. This competence of methanogen bacteria could be exploited for the commercial production of fuel gas and methane gas in the fuel plants or the gobar gas plants.