NEET BIOLOGY

Detailed explanation-1: -Autotrophic bacteria can make their own food from sunlight or chemical compounds. Heterotrophic bacteria get their energy from other organisms, either living or non-living.

Detailed explanation-2: -Heterotrophic bacteria obtain carbon and energy for growth from naturally occurring organic compounds, while autotrophs use carbon dioxide as their main source of carbon. Autotrophs obtain energy from light (photoautotrophs) or the oxidation of inorganic compounds such as ammonia (chemoautotrophs).

Detailed explanation-3: -Bacteria can be both autotrophic and heterotrophic. Autotrophic bacteria such as Cyanobacteria and Rhodospirillum contain pigment-containing vesicles called ‘chromatophores’. These vesicles contain carotenoids and bacteriochlorophyll that help in photosynthesis.

Detailed explanation-4: -Some varieties of bacteria use light to create their own food, just like organisms that use photosynthesis. However, these bacteria are not autotrophs, because they must rely on chemicals besides carbon dioxide for carbon.

Detailed explanation-5: -Such bacteria are called heterotrophic bacteria. Heterotrophic bacteria are of three types. Parasites, Saprotrophs and Symbionts. (1) Parasites : They obtain their organic food or special organic compounds required for their growth from living cells of plants and animals.