NEET BIOLOGY

Detailed explanation-1: -Archaebacteria are the most ancient and are called living fossils. So they are the oldest living beings.

Detailed explanation-2: -Solution : (d) The archaebacteria are able to flourish in extreme conditions of environment that are believed to have existed on the primitive earth. It is believed that these represent the early forms of life. Hence, archaebacteria are called “oldest, living beings” .

Detailed explanation-3: -Archaeans are an ancient form of life, possibly the most ancient. Putative fossils of archaean cells in stromatolites have been dated to almost 3.5 billion years ago, and the remains of lipids that may be either archaean or eukaryotic have been detected in shales dating from 2.7 billion years ago.

Detailed explanation-4: -4.4. Archaebacteria are a group of microorganisms considered to be an ancient form of life that evolved separately from the bacteria and blue-green algae, and they are sometimes classified as a kingdom.

Detailed explanation-5: -These names have stuck, though a battle continues over whether another word-prokaryotes, meaning Bacteria plus Archaea together-has any legitimate use. And it is no longer believed that Archaea are any older than Bacteria, as their name and the New York Times headline might imply.