Viruses Section 19–2 This section describes the structure of a virus. It also explains how viruses cause infection.

Slides:

Advertisements

Similar presentations

Section 2: Viruses Preview Bellringer Key Ideas Is a Virus Alive?

Advertisements

Review What do viruses depend on for their reproduction

Lesson Overview 20.1 Viruses.

Viruses Wkbk 20.1 Watch for vocab, diagrams, and understanding structure and function of viruses.

Unit 5: Classification and Kingdoms

Genetics of Viruses.

Lesson Overview 20.1 Viruses.

Life Cycles of Viruses.

Bacteria and Viruses.

CHAPTER 19 BACTERIA AND VIRUSES.

Chapter 19 Page 478. The phylogeny of the virus No fossil evidence Only speculation by scientists about how viruses came to be --- Some think that their.

Lesson Overview 20.1 Viruses.

Biology Virus Notes.

Mr. Karns Biology Viruses.

Viruses. Non-cellular particles of nucleic acid, protein, and in some cases lipids that can reproduce only by infecting living cells Differ widely in.

Viruses. Virus: Particles of nucleic acid, protein, some lipids Reproduce vicariously Use the cells they infect to build new viruses.

Chapter 20 Section 20-1: Viruses.

End Show Slide 1 of 34 Copyright Pearson Prentice Hall Biology.

End Show Slide 1 of 34 Copyright Pearson Prentice Hall Biology.

 Virus-particles of nucleic acid, proteins and in some cases, lipids.  A typical virus is composed of a core of DNA or RNA surrounded by a protein.

 Viruses- particles of nucleic acid, protein and sometimes lipids  Most viruses are so small, they can only be seen through a powerful electron microscope.

Biology II Virsus. Brief History Many years the cause viral infections such as smallpox and polio were unknown even though we knew they were transferred.

 Viruses are small infectious agents  They are so small that they can only be seen with a very powerful electron microscope Ebola Virus under electron.

State Standard SB3D. Compare & contrast viruses with living organisms. Viruses (18.2)

Viruses. What Is a Virus? Viruses are particles of nucleic acid (DNA/RNA), and a protein coat. All viruses enter living cells and use the infected cell.

Created By: Kyana Pereira & Sindy Morales February 23, 2011 Period 8.

Virus Reading Guide.

VIRUSES DO NOW Are viruses alive? List one reason why or why not.

Lesson Overview Lesson Overview Studying the Human Genome Lesson Overview 20.1 Viruses.

Viruses Versus Living Organisms

 Maintain homeostasis  Reproduction  Cellular organization  Metabolism (use energy)  Contain genetic information.

Virology - study of viruses

Viruses For EOC Review. IV.Preventing Bacterial Disease 1. Vaccine- A preparation of a weakened or killed pathogen, such as a bacterium or virus. Body.

Viruses. Learning Objectives  Explain how viruses reproduce.  Explain what happens after a virus infects a cell.

Chapter 18.1: Viruses. 1. Viruses are composed of nucleic acids enclosed in a protein coat and are smaller than the smallest bacterium.

Lesson Overview Lesson Overview Studying the Human Genome Lesson Overview 20.1 Viruses.

Chapter 19 Page 478. The phylogeny of the virus No fossil evidence Only speculation:- ancestors were cellular parasites that gradually lost their cell.

Major Parts of a Virus - Bacteriophage

Viruses 1.Identify the structures of viruses 2.Explain the differences between the lytic and lysogenic cycles of viral reproduction 3.Recognize the medical.

Viruses. Tiny 1/2 to 1/100 the size of smallest bacterium Nonliving Do not fulfill the criteria for life Do not carry out respiration, grow or move Can.

Two Cycles and A Bit of Review Remember that viruses are not able to reproduce on their own. They rely on a ‘host cell’ for reproduction In the Lytic Cycle.

Review What do viruses depend on for their reproduction

Viruses Chapter 19 Page 478.

Biology Copyright Pearson Prentice Hall.

Bellwork Question: How does the common cold spread

Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall

Virus Notes Chapter 19 Section 19-2.

Lesson Overview 20.1 Viruses.

Viruses Review.

Virus Notes Chapter 19 Section 19-2.

Chapter 15 Viruses, Viral Life Cycles, Retroviruses.

Virus Characteristics

Arianna K. Olivia J. Willow G.

Virus A pathogen that consists of a Nucleic Acid – (DNA or RNA) wrapped in a Protein Coat- (Capsid). Classification: Classified by the host Bacteriophage.

Copyright Pearson Prentice Hall

Presentation transcript:

Viruses Section 19–2 This section describes the structure of a virus. It also explains how viruses cause infection.

What Is a Virus? What are Viruses? They are particles of nucleic acid, protein, and in some cases lipids that can reproduce only by infecting living cells.

What do all viruses have in common? They enter living cells and, once inside, use the machinery of the infected cell to produce more viruses.

Is the following sentence true or false? Most viruses are so small that they can be seen only with the aid of a powerful electron microscope. True

What Is a Virus? What is the structure of a typical virus? A typical virus is composed of a core of either DNA or RNA surrounded by a protein coat.

What Is a Virus? Circle the letter of what a virus’s protein coat is called. capsid

What Is a Virus? How does a typical virus get inside a cell? The capsid proteins bind to receptors on the surface of a cell and “trick” the cell into allowing it inside.

What Is a Virus? What occurs when viruses get inside of cells? Once inside, the viral genes are expressed. The cell transcribes and translates the viral genetic information into viral capsid proteins. Sometimes the program may cause the cell to make copies of the virus, and in the process the host cell is destroyed.

What Is a Virus? Why are most viruses highly specific to the cells they infect?

What Is a Virus? Viruses must bind precisely to proteins on the cell surface and then use a host’s genetic system.

What Is a Virus? What are bacteriophages? They are viruses that infect bacteria. Viral Infection

What Is a Virus? Why is a lytic infection given that name? The host cell is lysed and destroyed.

What Is a Virus? Circle the letter of each sentence that is true about a lysogenic infection. The virus embeds its DNA into the host’s DNA.

What Is a Virus? The virus’s DNA is replicated along with the host cell’s DNA. A host cell makes copies of the virus indefinitely.

Complete the flowchart about a lytic infection.

What Is a Virus? What is prophage? It is the viral DNA that is embedded in the host’s DNA.

What Is a Virus? Retroviruses What are retroviruses? They are viruses that contain RNA as their genetic information.

What Is a Virus? What happens when retroviruses infect a cell? They produce DNA copy of their RNA. This DNA is inserted into the DNA of the host cell.

What Is a Virus? Viruses and Living Cells Circle the letter of each reason why some biologists do not consider viruses to be alive. They can’t reproduce independently.