A. They have no nucleus
B. They can photosynthesize
C. They are unicellular and can survive extreme conditions
D. They are multicellular
Answer: They are unicellular and can survive extreme conditions
What is the primary characteristic of organisms in the kingdom Archaea?
Additional Information: Archaea are unicellular organisms known for their ability to live in extreme environments such as high temperature or salinity.
Subjects: Biological Classification, Biology