EVERYDAY SCIENCE

Detailed explanation-1: –Bacteria that use hydrogen and iron as a source of energy are hydrogen bacteria and iron bacteria respectively. So, the correct answer is ‘They prepare their own food without the help of sunlight’.

Detailed explanation-2: -Chemosynthesis is the synthesis of organic compounds by bacteria or other living organisms using energy derived from reactions involving inorganic chemicals, typically in the absence of sunlight.

Detailed explanation-3: -They generate sugars and amino acids from carbon dioxide with hydrogen sulfide as the energy source. This type of chemosynthesis produces carbohydrates and is also known as chemical synthesis. Examples of animals that use chemosynthesis include snails, scale worms, and limpets.

Detailed explanation-4: -Chemosynthesis is the process by which food (glucose) is made by bacteria using chemicals as the energy source, rather than sunlight. Chemosynthesis occurs around hydrothermal vents and methane seeps in the deep sea where sunlight is absent.

Detailed explanation-5: -Chemosynthesis is done mostly by bacteria that live in extreme conditions and where sunlight cannot be reached. Examples of some bacteria are Nitrosomonas, Beggiatoa, etc. These are nitrogen-fixing bacteria, sulphur oxidising bacteria and iron-oxidising bacteria.