Which Statement About the Domain Archaea is True

Question

Which statement about the domain Archaea is true?
A) Genetic prospecting has recently revealed the existence of many previously unknown archaean species.
B) No archaeans can reduce CO₂ to methane.
C) The genomes of archaeans are unique, containing no genes that originated within bacteria.
D) No archaeans can inhabit solutions that are nearly 30% salt.
E) No archaeans are adapted to waters with temperatures above the boiling point.

Accepted Answer

Genetic prospecting techniques have allowed scientists to identify many previously unknown species of Archaea.

Answer: B
 Many species of Archaea are known to reduce CO₂ to methane.

Answer: C
 Although archaeal genomes may contain some unique genes, many of their genes share homology with bacterial genes, indicating horizontal gene transfer between the two domains.

Answer: D
 Some species of Archaea, such as halophiles, are adapted to living in high-salt environments.

Answer: E
 Some species of Archaea, such as hyperthermophiles, are adapted to living in very hot environments, including waters with temperatures above the boiling point.