Define the term virus and identify what organisms viruses ca

Define the term virus, and identify what organisms viruses can What are the anatomical features of a typical virus? Describe the different shapes of viruses. and contrast enveloped and naked viruses.

Solution

1. Viruses are microscopic infective agents that are capable of multiplying only within a living cell.

Viruses infect all categories of living organisms.

2. Viruses are made up of a nucleic acid core and a protein coat. The nucleic acid can be either DNA or RNA and can be either double or single stranded. The subunits of the protein coat (capsid) are arranged in a helical or icosahedral symmetry.

3. Viruses can be-

helical- The capsid is rod shaped or filamentous.

icosahedral- The capsid is symmetrical.

4. In enveloped viruses, the capsid is surrounded by phospholipid, glycoprotein or protein. These viruses are less virulent and are sensitive to heat, acids etc.

Non enveloped viruses are more virulent and are resistant to heat and drying.