Question

‘Bacteria eaters’ are
(a) Viruses
(b) Bacteria
(c) Fungi
(d) Algae

Answer 1

Hint: The question refers to organisms that are able to occupy bacteria and consume them entirely. This process can be carried out by organisms that can invade the bacteria and act as parasites in nature.

Complete step by step answer:
- A group of viruses named as bacteriophages are known to invade bacteria and replicate inside them. Their name literally translates to ‘bacteria eaters’ as phage means ‘to devour’. They are also simply known as phages.
- Viruses infect bacteria by either the lytic cycle or the lysogenic cycle. In the lytic cycle, the cells lyse after the insertion of the genetic material and the replication of the single virus particle. In the lysogenic cycle, the cells do not lyse immediately. The genetic material of the virus is integrated into the host cell’s genome and is replicated. In conditions of low nutrition, the virus switches to the lytic phase and causes the cell to lyse.
- Phages are simple organisms composed of a protein structure, known as a capsid, that surrounds a segment of genetic material, which is either DNA or RNA. The genetic material can be single- or double-stranded.
- The structure of the capsid depends on the genome.
- The basic structure of phages is classified into three types - a filamentous form, an icosahedral/20-sided head with a tail, and an icosahedral head without a tail.
- Examples of viruses that are employed in research are T2, T4, T6, etc.
So, the correct answer is ‘(a) Viruses’

Note:
- Bacteriophages also infect prokaryotic Archaea.
- The genome of viruses are ‘mosaic’ - they contain numerous sequences that are found in other species of viruses in different arrangements.
- Viruses are used as anti-bacterial agents as an alternative to antibiotics in some countries. Phages are being considered as antibacterial therapy against antibiotic-resistant strains.