Q.Chemosynthetic bacteria obtain energy from

Chemosynthesis is a mode of autotrophic nutrition in which certain bacteria manufacture their own organic food without depending on light as an energy source. Unlike green plants, which are photoautotrophs relying on light energy captured by chlorophyll to drive the synthesis of organic compounds from CO2 and water, chemosynthetic bacteria derive the energy they need from purely chemical reactions — specifically, from the oxidation of inorganic substances such as ammonia, nitrites, sulphur or sulphur compounds, and iron compounds. Because their energy source is chemical rather than solar, chemosynthetic bacteria can survive and synthesise organic matter even in complete darkness, in environments sunlight never reaches — for example, deep-sea hydrothermal vents, waterlogged soils, or subsurface sediments. This distinguishes chemosynthesis conceptually from photosynthesis even though both are autotrophic processes that build organic matter from inorganic raw materials (CO2 and an inorganic hydrogen/electron donor). The name itself reflects this distinction: 'photo-' denotes a lig …