Question

Difficulty: EasyViruses: Structure and Characteristics

Viruses possess specialized structural components that enable them to protect their genetic material and infect host cells. Which viral structural component correctly matches each functional role?

  • Viral nucleic acidEncodes genetic instructions (either DNA or RNA) required for viral replication
  • CapsidForms a protective protein coat assembled from capsomeres around the genome
  • Viral envelopeConsists of an outer lipid membrane usually derived from host cell membranes
  • Tail fibersEnables specific binding of bacteriophages to surface receptors on host bacteria

Answer

Viral nucleic acid matches with encoding genetic instructions (DNA or RNA); Capsid matches with the protective protein coat made of capsomeres; Viral envelope matches with the lipid membrane derived from the host; Tail fibers match with enabling bacteriophage attachment to bacterial receptors.
Each viral structure serves a specialized role: nucleic acid carries genetic code (DNA or RNA), the capsid serves as the primary protein protective coat, the envelope provides a lipid covering derived from host cells, and tail fibers mediate specific attachment of bacteriophages to host bacteria.

Step-by-Step Solution

1
Identify the genetic core of viruses
Viral nucleic acid contains either DNA or RNA as its genetic material.
Viruses rely on their core nucleic acid to direct host cell machinery during replication.
2
Identify the protective protein layer
The capsid is the protein coat composed of capsomere subunits.
The capsid protects the viral genome from nucleases and environmental degradation.
3
Distinguish between enveloped and non-enveloped structural layers
The envelope is an outer lipid layer obtained during viral budding from host membranes.
Host membrane lipids form the viral envelope surrounding certain viruses.
4
Identify specialized bacterial virus (bacteriophage) attachment structures
Tail fibers anchor the phage to specific bacterial host receptors.
Complex viruses rely on tail fibers for target host recognition.

Key Concept

Structural organization of viruses: core genetic material (DNA or RNA), protein capsid, host-derived envelope, and phage attachment structures.
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