NEET BIOLOGY

Detailed explanation-1: -Some types of bacteria are autotrophs. Most autotrophs use a process called photosynthesis to make their food. In photosynthesis, autotrophs use energy from the sun to convert water from the soil and carbon dioxide from the air into a nutrient called glucose.

Detailed explanation-2: -Autotrophic bacteria synthesize all their cell constituents using carbon dioxide as the carbon source. The most common pathways for synthesizing organic compounds from carbon dioxide are the reductive pentose phosphate (Calvin) cycle, the reductive tricarboxylic acid cycle, and the acetyl-CoA pathway.

Detailed explanation-3: -The autotrophic bacteria examples included in this category are Nostoc, Anabaena, etc. Anaerobic Photosynthetic Bacteria: The most common example of photosynthetic bacteria is anaerobic photosynthetic bacteria. Instead of water they use hydrogen sulphide or thiosulphate as a reducing agent.

Detailed explanation-4: -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-5: -Autotrophic bacteria synthesize their own food. They derive energy from light or chemical reactions. They utilize simple inorganic compounds like carbon dioxide, water, hydrogen sulfide, etc. and convert them into organic compounds like carbohydrates, proteins, etc. to supplement their energy requirements.