1 / 28

Table of Contents

Viruses. Chapter 24. Table of Contents. Section 1 Viral Structure and Replication Section 2 Viral Diseases. Section 1 Viral Structure and Replication. Chapter 24. Objectives. Summarize the discovery of viruses. Describe why viruses are not considered living organisms.

venecia
Download Presentation

Table of Contents

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Viruses Chapter 24 Table of Contents Section 1 Viral Structure and Replication Section 2 Viral Diseases

  2. Section 1 Viral Structure and Replication Chapter 24 Objectives • Summarizethe discovery of viruses. • Describewhy viruses are not considered living organisms. • Describethe basic structure of viruses. • Comparethe lytic and lysogenic cycles of virus replication. • Summarizethe origin of viruses.

  3. Section 1 Viral Structure and Replication Chapter 24 Discovery of Viruses • Researchers in the late 1800s discovered that something smaller than bacteria could cause disease. • In 1935, ________________ ______________ demonstrated that viruses were not cells when he crystallized _______, the virus that causes tobacco mosaic disease in tobacco and tomato plants.

  4. Section 1 Viral Structure and Replication Chapter 24 Characteristics of Viruses • Viruses do not have all of the characteristics of life and are therefore

  5. Section 1 Viral Structure and Replication Chapter 24 Characteristics of Viruses, continued • Viral Size and Structure • Viruses are nonliving particles containing DNA or RNA and are surrounded by a protein coat called a ______________________. • Some viruses also have an _______________ that is derived from a host cell’s nuclear membrane or cell membrane.

  6. Section 1 Viral Structure and Replication Chapter 24 Characteristics of Viruses, continued • Classification of Viruses • Viruses can be classified based on whether they have __________ or _________, whether the RNA or DNA is _____________ or ____________ stranded and ______________ or ____________, by ____________ ______________, and whether or not they have an ___________________.

  7. Section 1 Viral Structure and Replication Chapter 24 Viral Replication, continued • Replication in DNA Viruses • DNA viruses can enter host cells and directly produce RNA, or they can insert into a host’s chromosome, where they are

  8. Section 1 Viral Structure and Replication Chapter 24 Viral Replication, continued • Replication in RNA Viruses • The RNA genome of some RNA viruses can be • ____________________ use ____________ ___________________ and RNA as a template to make DNA, which is then used to produce viral RNA and proteins.

  9. Section 1 Viral Structure and Replication Chapter 24 Viral Replication, continued • Replication in Viruses That Infect Prokaryotes • Bacteriophages are

  10. Section 1 Viral Structure and Replication Chapter 24 Viral Replication, continued • Lytic Cycle • Viruses can follow a lytic cycle, making new viral particles immediately.

  11. Section 1 Viral Structure and Replication Chapter 24 Viral Replication, continued • Lysogenic Cycle • Viruses can follow a lysogenic cycle, becoming part of the host genome and making new particles later.

  12. Section 1 Viral Structure and Replication Chapter 24 The Lytic and Lysogenic Cycles

  13. Section 1 Viral Structure and Replication Chapter 24 Viral Replication, continued • Viruses: Tools for Biotechnology • Viruses are important tools for biotechnology.

  14. Section 1 Viral Structure and Replication Chapter 24 The Origin of Viruses • Most scientists think viruses originated from

  15. Section 2 Viral Diseases Chapter 24 Objectives • Nameseveral vectors of viral diseases. • Identifyfour viral diseases that result in serious human illnesses. • Discuss the relationship between viruses and cancer. • Namethree examples of emerging viral diseases. • Comparethe effectiveness of vaccination, vector control, and drug therapy in fighting viruses. • Contrastviroids, prions, and viruses.

  16. Section 2 Viral Diseases Chapter 24 Vectors of Viral Diseases • Vectors, or hosts, of viral diseases include

  17. Section 2 Viral Diseases Chapter 24 Human Viral Diseases • Viruses cause many human diseases, including the

  18. Section 2 Viral Diseases Chapter 24 Human Viral Diseases, continued • Chickenpox and Shingles • Chickenpox and shingles are caused by the same varicella-zoster herpesvirus.

  19. Section 2 Viral Diseases Chapter 24 Human Viral Diseases, continued • Viral Hepatitis • Hepatitis, or inflammation of the liver, can be caused by at least five viruses. • Hepatitis A and hepatitis E can be spread by • Hepatitis B, C, and D are spread by

  20. Section 2 Viral Diseases Chapter 24 Human Viral Diseases, continued • Acquired Immune Deficiency Syndrome (AIDS) • The human immunodeficiency virus (HIV) is an RNA virus spread by sexual contact, by contact with infected body fluids, and from mother to fetus. • HIV targets _____________________ and thus damages the body’s immune system. The disease called acquired immune deficiency syndrome (AIDS) results.

  21. Section 2 Viral Diseases Chapter 24 AIDS (Acquired Immunodeficiency Syndrome)

  22. Section 2 Viral Diseases Chapter 24 Human Viral Diseases, continued • Viruses and Cancer • Some viruses contain _________________ that can cause cancer, while other viruses convert___________________________, which usually control cell growth,tooncogenes.

  23. Section 2 Viral Diseases Chapter 24 Emerging Viral Diseases • Emerging viruses usually infect animals isolated in nature but can jump to humans when

  24. Section 2 Viral Diseases Chapter 24 Prevention and Treatment • Vaccinations • A vaccine contains a harmless version of a virus, bacterium, or a toxin that causes • Vaccines have helped to greatly reduce certain viral diseases.

  25. Section 2 Viral Diseases Chapter 24 Prevention and Treatment, continued • Vector Control • Control efforts, including killing mosquitoes and other vectors and quarantining ill patients, have helped reduce the spread of certain viral diseases.

  26. Section 2 Viral Diseases Chapter 24 Prevention and Treatment, continued • Drug Therapy • _____________________ are ineffective against viral diseases. • Viral drugs, such as acyclovir, block

  27. Section 2 Viral Diseases Chapter 24 Virods and Prions • ____________________ are short, circular, single strands of RNA lacking a capsid that infect plant cells. • _____________________ are infectious particles containing protein but no nucleic acids. • Prions cause mad cow disease and similar degenerative brain diseases.

  28. Section 2 Viral Diseases Chapter 24 Important Viral Diseases

More Related