Question

Which of the following is not true about archaebacteria.
(1) Cell wall is made up of peptidoglycan
(2) Include extreme halophiles, thermophues and methanogens
(3) Lipids in cell membrane have phytanyl side chain
(4) Lipids in cell membrane have fatty acid side chain

• A. 1, 2 and 3 are correct
• B. 1 and 2 are correct
• C. 2 and 4 are correct
• D. 1 and 3 are correct

Answer 1

Answer: (D)

The term 'archaebacteria' refers to the ancient origin of this group of bacteria, which seems to have diverged very early from eubacteria. These inhabit some of the most extreme environments on earth and include methanogens, extremophiles (thermophiles, pH tolerant, pressure tolerant), etc. Their cell wall lacks peptidoglycan (which is an important component of cell wall of eubacteria). Lipids in the cell membrane of archaebacteria have phytanyl side chain while those of eubacteria and eukaryotes have fatty acid side chain.