The domain of the new species of unicellular microorganism in an undersea thermal vent that lacks a nucleus is Archeae.
Domain in biology refers to the highest rank in the classification of organisms, above kingdom.
The three domain of organisms are as follows:
Members of Prokarya and Archaea do not possess a membrane-bound nucleus, however, the major difference between them is that members of domain Archaea are found in extreme habitats e.g. hot regions.
Therefore, the domain of the new species of unicellular microorganism in an undersea thermal vent that lacks a nucleus is Archeae.
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