LIFE SCIENCE

Detailed explanation-1: -Archaea are single-celled microorganisms with structure similar to bacteria. They are evolutionarily distinct from bacteria and eukaryotes and form the third domain of life. Archaea are obligate anaerobes living in environments low in oxygen (e.g., water, soil).

Detailed explanation-2: -Some archaeal species survive in both aerobic and anaerobic conditions.

Detailed explanation-3: -Archaea are microorganisms that define the limits of life on Earth. They were originally discovered and described in extreme environments, such as hydrothermal vents and terrestrial hot springs. They were also found in a diverse range of highly saline, acidic, and anaerobic environments.

Detailed explanation-4: -The domain Archaea is a group of unusual organisms and is known to include three groups: methanogens, extreme halophiles, and thermoacidophiles.