Question

Name the causative agent of Polio
(a) HIV virus
(b)Poliovirus
(C) Both A and B
(d) None of the above

Answer 1

Hint: Polio is a disease that attacks a person’s spinal cord and may lead to paralysis at its worst stage. The causative agent of Polio is a type of organism that is lifeless without any host to provide shelter and nutrients. It attacks the central nervous system of its host.

Complete answer:
Viruses are obligate parasites that require host machinery to fulfill their life requirements. They are composed of genetic material encapsulated by a protein coat known as a capsid. Poliovirus causes polio or poliomyelitis. Its genetic material is a single-stranded RNA enclosed in an icosahedral capsid. The oral poliovirus vaccine is given to infants to prevent them from infection by poliovirus.

Additional Information:
 -The structure of the virus is varied in terms of size, shape, and chemical composition. These obligate intracellular parasites are smaller than prokaryotic cells ranging in size from 0.02 to 0.3μm.
-The genetic material in a virus can be both DNA or RNA. DNA is double-stranded while RNA can be both single-stranded or double-stranded.
-The nucleic acid is encapsulated in a protein coat known as a capsid. Its responsibility is to protect the viral genome from nucleases and also to firmly attach to the host cell when trying to penetrate the host cell.
-A group of viruses with RNA genome carrying reverse transcriptase is known as retroviruses. They make a DNA copy of their genome upon invading a host cell.
-HIV or Human Immunodeficiency Virus is an enveloped lentivirus is a retrovirus belonging to the family retroviridae. It causes deadly AIDS or Acquired ImmunoDeficiency Syndrome, where a person experiences a marked deficiency in the cellular immune response. This occurs due to a significant drop in the subpopulation of T-cells.

So, the correct answer is ‘Poliovirus.’

Note: The virus uses specific receptors on the cell surface for attachment. The cell to which it binds is referred to as the host. This attachment is succeeded by virus penetration into the host. It does so by various methods like directly penetrating its genome or fusing with the host’s plasma membrane or through receptor-mediated endocytosis.