Question

Organisms called methanogens are most abundant in:

• A. Hot spring
• B. Sulphur rock
• C. Cattleyard
• D. Polluted stream

Answer 1

The correct option is C

Cattleyard

Methanogens are a group of bacteria which are capable of producing methane and hydrogen gas. When cows feed on grass and other plants that are rich in cellulose, the food enters the food pipe and reaches the rumen of the cow - a part of the stomach. Here the plant fibres are acted upon by generic microbes that ferment the cellulose to release $C{O}_2$ and $H_2$ gas. In another part of cow's gut, the methanogens soak up the hydrogen to form $C{H}_4$. Because methanogens tend to reside in the intestinal tract of cattle, cattle dung provides a rich source of these important microbes. Thus, methanogens are abundant in a cattle yard.