Question

Viral capsids are made up of morphological subunits called capsomers. One of the common capsomeres is icosahedral. The icosahedron is a regular polyhedron with

• A. 16 triangular facets and 12 vertices
• B. 20 triangular facets and 12 vertices
• C. 16 triangular facets and 16 vertices
• D. 20 triangular facets and 16 vertices

Hint:

The icosahedral structure is a highly symmetrical polyhedron often found in viral capsids, featuring 20 equilateral triangular faces and 12 vertices.

Answer 1

The Correct Option is B

Step 1: Understanding Icosahedral Structure. 
An icosahedron is a polyhedron with 20 faces, each an equilateral triangle. It has 12 vertices and 30 edges, making it a highly symmetrical structure often found in viral capsids. 
 

Step 2: Analyzing the options. 
(A) 16 triangular facets and 12 vertices: Incorrect — An icosahedron has 20 facets, not 16. 
(B) 20 triangular facets and 12 vertices: Correct — This corresponds to the structure of the icosahedron. 
(C) 16 triangular facets and 16 vertices: Incorrect — This is not a valid description for the icosahedral structure of a viral capsid. 
(D) 20 triangular facets and 16 vertices: Incorrect — While icosahedral structures have 20 facets, they have 12 vertices. 
 

Step 3: Conclusion. 
The correct answer is (B) 20 triangular facets and 12 vertices