Question

Methanogens belong to -

• A. Eubacteria
• B. Archaebacteria
• C. Dinoflagellates
• D. Slime moulds

Answer 1

The Correct Option is B

The correct answer is Option 2: Archaebacteria.

Explanation:

Methanogens are a type of archaebacteria (also known as archaea) that produce methane as a by-product of their metabolism. They are typically found in anaerobic environments, such as the intestines of ruminants, swamps, and marshes. Methanogens play a crucial role in the carbon cycle by producing methane (CH4), a potent greenhouse gas.

Eubacteria (Option 1) refers to the "true bacteria" that are different from archaea.

Dinoflagellates (Option 3) are a group of protists, many of which are marine plankton, and are not involved in methane production.

Slime moulds (Option 4) are a group of eukaryotic organisms that exhibit both amoeba-like and fungal-like characteristics, and they do not produce methane.

Thus, methanogens belong to Archaebacteria, which is Option 2.

Answer 2

Answer: Methanogens belong to Archaebacteria.

Detailed Explanation:

Methanogens are microorganisms that produce methane as a by-product of their metabolism. They belong to the domain Archaebacteria, which is distinct from the true bacteria (Eubacteria). Methanogens are known for their ability to carry out anaerobic respiration, in which they use carbon dioxide (CO₂) and hydrogen (H₂) to produce methane (CH₄).

These microorganisms are typically found in extreme environments like swamps, marshes, the intestines of ruminants (e.g., cows, sheep), and other anaerobic conditions where oxygen is absent. Methanogens play an essential role in the carbon cycle and are important in the global methane cycle, a potent greenhouse gas.

Key Features of Methanogens:

Anaerobic Respiration: Methanogens generate methane by reducing carbon dioxide in the absence of oxygen. This process is part of their metabolic pathway.

Extreme Environments: Methanogens are found in environments without oxygen, such as the deep ocean, marshes, and the digestive tracts of animals.

Cell Wall and Membranes: Unlike typical bacteria, archaebacteria, including methanogens, have ether-linked lipids in their cell membranes, which help them survive extreme conditions. They lack peptidoglycan in their cell walls, distinguishing them from Eubacteria.

Obligate Anaerobes: Methanogens cannot survive in the presence of oxygen, as oxygen is toxic to them. This makes them obligate anaerobes.

Overall, methanogens are integral in producing methane gas, contributing to the methane cycle, and are vital components of anaerobic ecosystems.