Class 11 NEET Biology Biological Classification Questions Part 1

(d) : Archaebacteria are believed to have originated at a time when there were extreme conditions in the biosphere. Even today they are found in environments where other kinds of bacteria cannot survive. So they are considered to be the oldest of the living fossils. Eg. Methanobacterium, Methonococcus etc. All of them are not halophiles. Only some forms like Halobacterium, Halococcus can survive under extreme saline conditions. All of them are not fossils because many forms are still surviving and flourishing.