Question

Euryarchaeota belongs to
a) Eubacteria
b) Archaea
c) Eukarya
d) None of the above

Answer 1

Hint: Euryarchaeota is the organism that is generally halophiles and methanogens in nature. They live in salty habitats and need salt to survive. They help in the removal of methane via anaerobic oxidation of the methane.

Complete answer:
Euryarchaeota belongs to domain archaea. They are highly diverse in nature. They can survive in high salt and high-temperature conditions. They can be aerobic and anaerobic in nature. They generally have temperatures ranging from $41^\circ C - 122^\circ C $. They can be distinguished on the basis of their unique DNA polymerases.

Additional information:
- Eubacteria are true bacteria. Eubacteria domain consists of all the bacteria which include proteobacteria, cyanobacteria, spirochetes, chlamydia, and gram-positive bacteria. They are unicellular bacteria. Their cell wall composition is mainly of peptidoglycan. They have a cell membrane that is made up of lipids. They may be rod-shaped or spherical shaped bacteria. They can be motile with the presence of flagella or non-motile in nature.
- Eukaryotes have true cell organelles present in them. They have a rod-shaped chromosome. Mitochondria present in them provide ATP. They have a membrane-bound nucleus. So, their nucleus is called the true nucleus. Their cell organelles are all membrane-bound. Eukarya differs from the archaea and eubacteria with respect to their structure. It has an advanced type of cell organelle whereas the other two have primitive types of cell organelles.
So, the answer is ‘b) Archaea’.

Note: Under the three-domain system, Archaea is the most primitive type. It is one of the oldest known domains. The bacteria which aren’t included in the Archaea are included in the bacteria or eubacteria domain. And all the eukaryotes are included in the eukarya domain.