EVERYDAY SCIENCE

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: -Photoautotrophs are cells that capture light energy, and use carbon dioxide as their carbon source. There are many photoautotrophic prokaryotes, which include cyanobacteria.

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 all their cell constituents using carbon dioxide as the carbon source.