Question

which characteristic distinguishes organisms in kingdom archaebacteria from organisms in kingdom eubacteria?

a. most organisms in kingdom archaebacteria live in extreme environments, while most organisms in kingdom eubacteria live in moderate environments.

b. most organisms in kingdom archaebacteria are single - celled, while only some organisms in kingdom eubacteria are single - cell.

c. organisms in kingdom archaebacteria are rod shaped, and organisms in kingdom eubacteria are only cocci or spiral shaped.

d. organisms in kingdom archaebacteria have circular dna, and organisms in kingdom eubacteria have linear dna.

Explanation:

To solve this, we analyze each option:

• Option A: Archaebacteria are known for thriving in extreme environments (like hot springs, salt flats), while Eubacteria (true bacteria) are more common in moderate environments. This is a key distinction.
• Option B: Both Archaebacteria and Eubacteria are predominantly single - celled. So this is incorrect.
• Option C: Both Archaebacteria and Eubacteria can have various shapes (rod, cocci, spiral). So this is incorrect.
• Option D: Both Archaebacteria and Eubacteria typically have circular DNA. So this is incorrect.

Answer:

A. Most organisms in kingdom Archaebacteria live in extreme environments, while most organisms in kingdom Eubacteria live in moderate environments.