Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Name: Mrs. Elizabeth Pitchiah Planned lesson date: 3/13/2014 Subject: Genetics Grade: 9-12 Lesson Objectives 2 or 3 student outcomes Begin with verb National/ State Standards AL College & Career Ready Course of Study - Common Core Learning Targets / District Standards National Standards (NCTM; NCTE; etc.,) Pre-Instructional activities Review Formative Assessment Introductory Set Prior Knowledge Essential Questions Problem Question Writing Prompts Predictions / Purpose Vocabulary Students will be able to describe the differences between RNA and DNA viruses, and the lytic cycle and lysogenic cycle (Alabama COS.11) Describe the replication of DNA and RNA viruses, including lytic and lysogenic cycles, using diagrams. 1. Review: Review with your students what they know about viruses. Be sure they understand that viruses occur in plants, as well as animals. (You might cite the tobacco mosaic virus, which kills tobacco plants.) 2. Formative assessment/Do now: Have you ever missed an important game due to flu? Ask students what causes the flu. How could we prevent getting the flu? 3. Introductory set: If students could answer that a virus causes the flu, ask them what other diseases are caused by viruses? Explain to the students that they would be learning about viruses, and more specifically about the replication of DNA and RNA viruses. Show the students the following youtube clip about influenza: http://www.youtube.com/watch?v=TVLo2CtB3GA&feature=related. This would lead into the lesson about viruses. 4. Essential questions: What is a virus? How does virus reproduce? How does virus infect humans? 5. Vocabulary: Virus: a disease causing, non-living particle made of proteins, nucleic acids and sometimes lipids; inside living cells called host cells. Capsid: Outercoat of protein that surrounds a virus's inner core of nucleic acid; arrangement of capsid proteins gives a virus its shape. Bacteriphage: viruses that infect bacteria, also called phages. Prophage: when the DNA temperate phage is integrated into the host's chromosome Lysogenic cycles: viral replication cycle in which a virus's nucleic acid is integrated into a host cell's chromosome; a provirus is formed and replicated each time the host cell reproduces; the host cell is not killed until the lytic cycle is activated. Lytic cycle: viral replication cycle in which a virus takes over a host cell's genetic material and uses the host cell's structures and energy to replicate until the host cell bursts, killing it. Provirus: viral DNA that is integrated into a host cell's chromosome and replicated each time the host cell replicates. Retrovirus: RNA virus that contains reverse transcriptase. Teaching Direct Teaching Graphic Organizers Reading Instruction Tech Integration Teacher Demonstration Guided Practice Independent Practice Small Group Activities Experiential Activities Research / Study Simulations Problem Solving Activities Differentiated Instruction Accommodations Ongoing Assessment Direct teaching: (Give students the vocabulary worksheet) 1. Use Prezi to explain that viruses are classified as a non-cellular particle made up of protein-covered genetic material that can invade living cells. Then explain the discovery of viruses. 2. Demonstrate how to make a model of virus. Provide the material needed for a virus model. Place students in pairs and guide them to make a model of virus. 3. What is a virus? (Give the work sheet to label parts of virus) 4. Describe the different parts of a virus by labeling a diagram. 5. Explain that virus reproduction requires a cell, and that there are two types of reproduction cycles: lytic and lysogenic. 6. Show the animation for lytic cycle- Explain 7. Differentiated instruction: Ask students a. What is the first step in lytic cycle? b. What happens after virus gets into cell? c. What happens after many copies of virus have been made? 8. Show the animation for lysogenic cycle- Explain 9. Independent practice: Independently students could compare and contrast lytic and lysogenic cycles. 10. Show the youtube video that summarizes the lytic and lysogenic cycles. Closure Summary / Conclusions Re-teaching Formative Assessment Review Reflection 1. Whole class: Review “What is virus?” 2. State 3 things that you learned from the lesson- Collect an exit slip Key questions: What is a virus? How does virus infect humans? Vocabulary Virus: a disease causing, non-living particle made of proteins, nucleic acids and sometimes lipids; inside living cells called host cells. Capsid: Outercoat of protein that surrounds a virus's inner core of nucleic acid; arrangement of capsid proteins gives a virus its shape. Bacteriphage: viruses that infect bacteria, also called phages. Prophage: when the DNA temperate phage is integrated into the host's chromosome Lysogenic cycles: viral replication cycle in which a virus's nucleic acid is integrated into a host cell's chromosome; a provirus is formed and replicated each time the host cell reproduces; the host cell is not killed until the lytic cycle is activated. Lytic cycle: viral replication cycle in which a virus takes over a host cell's genetic material and uses the host cell's structures and energy to replicate until the host cell bursts, killing it. Provirus: viral DNA that is integrated into a host cell's chromosome and replicated each time the host cell replicates. Retrovirus: RNA virus that contains reverse transcriptase. Enveloped with helical nucleocapsid (influenza virus) How a Virus Infects You Viruses lie around our environment all of the time just waiting for a host cell to come along. They can enter us through the nose, mouth or breaks in the skin. Once inside, they find a host cell to infect. For example, cold and flu viruses will attack cells that line the respiratory or digestive tracts. The human immunodeficiency virus (HIV), which causes AIDS, attacks the Tcells of the immune system. Regardless of the type of host cell, all viruses follow the same basic steps in what is known as the lytic cycle http://sites.fas.harvard.edu/~biotext/animations/lyticcycle.html 1. 2. 3. 4. 5. 6. A virus particle attaches to a host cell. The particle releases its genetic instructions into the host cell. The injected genetic material recruits the host cell's enzymes. The enzymes make parts for more new virus particles. The new particles assemble the parts into new viruses. The new particles break free from the host cell. All viruses have some type of protein on the outside coat or envelope that "feels" or "recognizes" the proper host cell(s). This protein attaches the virus to the membrane of the host cell. Some enveloped viruses can dissolve right through the cell membrane of the host because both the virus envelope and the cell membrane are made of lipids. Those viruses that do not enter the cell must inject their contents (genetic instructions, enzymes) into the host cell. Those viruses that dissolve into a cell simply release their contents once inside the host. In either case, the results are the same. Lysogenic Cycle Once inside the host cell, some viruses, such as herpes and HIV, do not reproduce right away. Instead, they mix their genetic instructions into the host cell's genetic instructions. When the host cell reproduces, the viral genetic instructions get copied into the host cell's offspring. The host cells may undergo many rounds of reproduction, and then some environmental or predetermined genetic signal will stir the "sleeping" viral instructions. The viral genetic instructions will then take over the host's machinery and make new viruses as described above. This cycle, called the lysogenic cycle, is shown in the accompanying figure. Because a virus is merely a set of genetic instructions surrounded by a protein coat, and because it does not carry out any biochemical reactions of its own, viruses can live for years or longer outside a host cell. Some viruses can "sleep" inside the genetic instructions of the host cells for years before reproducing. For example, a person infected with HIV can live without showing symptoms of AIDS for years, but he or she can still spread the virus to others. In the lytic cycle, the bacterial cell wall is ruptured and the progeny phages are released. Thus the host is destroyed. In the lysogenic cycle, the host remains intact and through excision the progeny is released. Both are the cycles describing the proliferation of bacteriophages in a host bacterial cell. lytic: shorter, immediate symptoms, does not take over dna of cell lysogenic: longer, can remain dormant for years, prolonged symptoms, takes over or bcomes part of cells dna similarities: both produce viruses in the end contrast In lytic cycle, the virus is virulent i.e. infectious. In lysogenic life cycle, the virus may remain non infectious due the suppressor enzyme which acts on itself. if this enzyme is somehowq destryoed the virus enters virulent stage again & undergo lytic cycle Objectives Students will understand the following: 1. A virus is an infectious organism that reproduces within the cells of an infected host. 2. A virus is not alive until it enters the cells of a living plant or animal. 3. A virus contains genetic information wrapped in a protein coat. 4. Viruses can be useful as well as harmful. 5. A virus that mutates ensures its own survival by making itself unrecognizable to immune systems and vaccines. 6. Even viruses engineered for useful purposes can be harmful if unchecked. http://www.discoveryeducation.com/teachers/free-lesson-plans/understanding-viruses.cfm http://www.ck12.org/biology/DNA-Structure-and-Replication/ http://education-portal.com/academy/lesson/viruses-bacteriophage-lytic-and-lysogeniccycles.html#lesson