Ch 7: Intro to Viruses
About This Chapter
Intro to Viruses - Chapter Summary and Learning Objectives
The lessons in this chapter cover the basics on viruses, from the life cycle of a virus to the variety of viral classes. If you have any questions about viruses, our expert instructors are available to answer your questions. The chapter topics are designed to teach you about:
- How DNA and RNA viruses replicate
- Virus shapes
- How viruses replicate their genomes
- Basic components of a virus
- The flu and HIV viruses
Video | Objective |
---|---|
What Are Viruses? - Definition, Structure & Function | Discuss the discovery of viruses and their basic composition. |
Shapes of a Virus: Helical, Icosahedral, Prolate, Complex & Enveloped | Learn about virus shapes and how these shapes help with identification. |
The Life Cycle of a Virus: How Viruses Live, Attack & Replicate | Explore how a virus attaches to and lives within a host. |
Classification of Viruses: Viral Genome and Replication Scheme | Go over the classification schema for viruses and explore the defining characteristics of each class. |
Replication of DNA Viruses | Learn about the process in which DNA viruses replicate within their host. |
Replication of RNA Viruses | Examine how RNA viruses reproduce within a cell. |
How Viruses Mutate: Antigenic Drift and Antigenic Shift | Track virus mutation and the ways viruses evade the immune system. |
Viruses: Bacteriophage Lytic and Lysogenic Cycles | Discuss the two different cycles of virus reproduction. |
Flu Viruses, HIV and Immune System Evasion | Look into these well-known virus types. |

1. What Are Viruses? - Definition, Structure & Function
In this lesson, you'll learn some historical facts about viruses and the material they are composed of. Find out more as we review the capsid, nucleic acids, the viral envelope, viruses, virions, bacteriophages and virology.

2. Shapes of a Virus: Helical, Icosahedral, Prolate, Complex & Enveloped
Learn about the different shapes viruses can have, such as helical, icosahedral, prolate, complex and enveloped. Find out why one shape is particularly useful from an energetic standpoint.

3. The Life Cycle of a Virus: How Viruses Live, Attack & Replicate
Find out how viruses infect and replicate as we explore the important steps of the virus life cycle, including attachment, uncoating, penetration, replication, and release, as well as the lysogenic and lytic cycles.

4. Classification of Viruses: Viral Genome and Replication Scheme
Find out how viruses are classified based on their being double-stranded, single-stranded, positive-sense, negative-sense, or by having something called reverse transcriptase.

5. Replication of DNA Viruses
This lesson will give you a basic overview of how DNA viruses replicate inside of a host cell. We will cover the entry, integration, replication and release of DNA viruses.

6. Replication of RNA Viruses
This lesson will give you a basic overview of how different types of RNA viruses replicate inside of an animal cell. We will cover the essence of being double-stranded and retroviruses, as well as positive-and negative-sense RNA viruses.

7. How Viruses Mutate: Antigenic Drift and Antigenic Shift
This lesson will discuss the major ways by which viruses, notably the flu virus, mutates. We will talk about recombination, reassortment, antigenic drift, antigenic shift, and more!
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Other Chapters
Other chapters within the Biology: High School course
- Basic Terms & Skills in Biological Science
- Analyzing Scientific Data
- Inorganic and Organic Chemistry for High School Biology
- Enzyme Function, Interactions & Regulation
- Cell Biology
- Bacterial Biology Overview
- Metabolic Biochemistry for High School
- Cell Growth & The Process of Cell Division
- Nucleic Acids: DNA & RNA
- Requirements of Biological Systems
- The Transcription and Translation Process
- Mendelian Genetics & Mechanisms of Heredity
- Types & Effects of Genetic Mutations
- DNA Technology and Genomics
- Basic Molecular Biology Laboratory Techniques
- Geologic Time Scale
- Evolution Overview
- Plant Biology
- Plant Growth and Reproduction
- Introduction to Fungi
- Introduction to Invertebrates
- Introduction to Vertebrates
- Physiology: Circulatory, Respiratory, Digestive, Excretory, Muscuskeletal Systems
- Physiology: Nervous, Immune, Endocrine Systems
- Ecology & Environment
- Animal Reproduction & Development
- Animal Populations and Behaviors
- Teacher Resources for High School Biology
- Student Resources for High School Biology