Concept explainers
To review:
The comparison and differences between icosahedral and filamentous symmetry of viruses with examples.
Introduction:
The viral capsid protects and encloses the genetic material of a virus. It is a proteinaceous structure that can be either symmetric or asymmetric. During replication or reproduction of a virus, the genetic material is inserted into the host cytoplasm and the capsid remains outside.
Explanation of Solution
The symmetrical capsid of virus can be of two types: icosahedral and filamentous. This symmetrical geometry proves to be advantageous in packaging the repeating protein units that are produced from the genetic material of the virus. The differences between these shapes of viral capsid are given below:
1. The icosahedral capsid contains 20 triangular faces and each face is formed by three identical proteins that are asymmetrical. The filamentous capsid is composed of monomers that spiral around the genome of the virus.
2. The size of an icosahedral capsid is fixed, however, the length of a helical (filamentous) capsid can be increased to include larger sized
3. The filamentous viruses contain tail fibers at their end that mediate attachment to host cell surface. The icosahedral virus contains glycoprotein spikes in their membrane envelope to aid in attachment.
4. The example of viruses having icosahedral capsid are human immunodeficiency virus (HIV) and herpes simplex virus. The examples of filamentous virus are Ebola virus, influenza virus, and tobacco mosaic virus.
Want to see more full solutions like this?
Chapter 6 Solutions
Microbiology: An Evolving Science (Fourth Edition)
- Trace the evolutionary origin of viruses according to current hypotheses and describe research regarding the evolution of polydnaviruses.arrow_forwardFigure 17.5 Which of the following statements about virus structure is true? a. All viruses are encased in a viral membrane. b. The capsomere is made up of small protein subunits called capsids. c. DNA is the genetic material in all viruses. d. Glycoproteins help the virus attach to the host cell.arrow_forwardDescribe the four morphological classes of viruses, then diagram and give example of each.arrow_forward
- Compare and contrast the structure, life cycle, and host cell type of naked and enveloped viruses.arrow_forwardGive an example of each of the following types of viruses a. Double stranded DNA b. Single stranded DNA c. Positive sense RNA d. Negative sense RNA e. Retrovirusesarrow_forwardExplain the unique characteristics of viruses compared toliving cells.arrow_forward
- What is the mode of replication of the virus? (This can be presented as a diagram with narrative description)arrow_forwardDiscuss the structures found in a typical virus.arrow_forwardWhat probably plays the most important role in determining the tissue and host specificity of viruses? Give some specific examples.arrow_forward
- discuss the similarities and differences between animal and bacterial virus multiplication. (Words/concepts to include in your answer: attachment, adsorption, penetration, uncoating, synthesis, assembly, persistence, lysogeny, latency, release)arrow_forwardDescribe the properties of virus particles that contribute to their survival in the environment and transmission to cause human infectionarrow_forwardDiscuss the structure of virus.arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage LearningConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College