To explore viruses/infectious diseases, how they can infect the human body, compromise the immune system, and interfere with normal human body functions.
In middle school, students should examine the nature, causes, structure, and the basis of infectious diseases, including viruses. This lesson helps to introduce the concept of viruses, what type of life forms they are, how they can be transmitted, how they affect humans and interfere with normal body functioning, and what our immune systems are. Students also need to know what the difference is between a virus and a bacterium and how immunization and medication can affect them. Bacteria and viruses are known as pathogens. When students understand what causes infectious diseases, they can then begin to understand how they make us sick and sometimes cause us to die, how viruses can mutate in humans, and ultimately how they can be prevented and controlled.
Using several Web resources, students will be able to identify characteristics of viruses and infectious diseases, identify which diseases have been with us a long time, and how new viruses and diseases come about, such as HIV and Ebola that affect human immune systems, and which diseases that had been eradicated are recurring. You should focus your attention on the National Science Education standards listed here addressing these issues. Students will participate in short classroom activities to get them engaged and provide links to their own background knowledge. Students also will study what a vaccine is, who invented the first ones, what they need for their states, and what the controversy is about.
Using the websites and classroom discussions, students will create their virtual “Famous Virus/Infectious Disease Hall of Fame Museum.” In pairs or individually, students will choose one virus/infectious disease to study in-depth to demonstrate their understanding of the cause, nature, contamination, prevention, and how it affects humans. This activity can be done individually, in pairs, or in small groups.
Ideas in this lesson are also related to concepts found in the following National Science Education Standards:
- Life Science: Structure and Function in Living Systems (5-8) #6
- Life Science: Regulation and Behavior (5-8) #2
Preparation for Spread of a Disease Laboratory Activity:
- Fill all but one cup 3/4 full of slightly acidic water. The pH of tap water varies. To ensure samples are acidic, add a few drops of HCI into a gallon of water.
- Fill one cup 3/4 full of O.1M NaOH. Mark this tube discretely.
Note: The Virus/Infectious Disease Hall of Fame final activity will be done in the computer lab with access to the Internet. It can be completed in three, 45-minute class periods and then presented to the class in a final period. Students will use the pre-selected sites listed on their student esheet to gather their information. This activity can be presented as a webquest in a PowerPoint presentation.
Decide if you want students to work on this in small groups, with partners, or individually. Review the websites and select those you think are most relevant to each group. All of the sites are listed on the student esheet.
Prepare index cards with the names of viruses/diseases on one side and the descriptions of the illnesses on the other side.
To engage students in this lesson, have them begin by using their What’s Really Bugging You? student esheet to go to the Smallest Thing. Students should listen to the podcast first. Then they should read the background information in “Making Sense of the Research” section.
Once students have gone through this resource, ask them these questions:
- What is the difference between a living and a non-living thing?
- (Living things have certain characteristics that distinguish them from non-living things. Among them are: living things are composed of one or more cells; they metabolize [produce and use energy]; they can grow; they can respond to external stimuli; they can adapt to their environment; and they can reproduce.)
- What are viruses really? Are they a life form? In what way do they seem alive?
- (They can certainly grow and reproduce, and they use genetic material found in other forms of life. They can adapt to their environment—for example, by developing resistance to certain drugs)
- How are they different from bacteria?
- (Unlike bacteria, viruses lack the internal machinery that would allow them to metabolize and reproduce on their own. Instead, they hijack the host cell and use its metabolic processes to make more viruses. Outside of a host cell, a virus cannot function.)
- What are viroids and can they hurt us?
- (Viroids are just naked strands of genetic material—in other words, a virus without the bag. They’re known only to cause diseases in plants, and they can be as small as 10 nanometers.)
- How do we catch viruses and infectious diseases?
- (We can catch them by passing these harmful bacteria and viruses from person to person or from animal to person.)
- What is something simple that can be done to prevent spreading the illnesses?
- (We can wash our hands frequently.)
- Can you name some illnesses caused by viruses and bacteria?
- (Examples include the common cold, herpes, dysentery, and the flu.)
Now, write down the names of several viruses/diseases on index cards and put them in a hat (common cold, West Nile Virus, dysentery/stomach virus, influenza, etc.). Each piece should have the description of the illness on the back. Have each student choose one. Have them act out or describe their symptoms. The rest of the class has to guess what it is.
In this lesson, students will use several activities and Internet resources to develop an understanding of the nature of viruses and infectious diseases. Students will begin to develop an understanding of how viruses/infectious diseases can infect the human body and interfere with normal body functions, and how they can be treated or prevented.
To begin, students should use their student esheet to go to Your Health: The Science Inside resource and read pages 9-12. As they read this resource, they should think about answers to the questions found on the What’s Really Bugging You? student sheet (you can find answers to the questions on the What's Really Bugging You? teacher sheet).
After students have read the Science Inside, you could have them do the Spread of a Disease Laboratory Activity, if time permits. The way in which a disease spreads through a population demands the careful collection and analysis of data. When an outbreak of a serious disease occurs, scientists must track down the disease and determine its origin. In this lab activity/investigation, students will simulate the spread of an infectious disease and determine the original carrier of the disease.
Each student should have one cup and one pipette. Students may need to be instructed on how to use the pipettes properly. Students should walk around the room and, when you tell them to stop, each student should find one person at random and exchange a pipette-full of solution with him/her. The exchange is made by each person putting a dropperful of his/her solution into the other person's cup. He/she should write down the name of the person with whom he/she exchanges solution. Students should repeat step 4 two more times. When three rounds are completed, put six drops of indicator into each student’s test tube. Record the color. Infected students are in pink; all others are clear or yellow.
To assess students’ comprehension and knowledge-acquisition, have them do the Virus/Infectious Disease Hall of Fame. Your assessment should be determined by class discussion and the students’ final project in terms of content, including visual and multimedia if used, websites used, and class presentation. An alternative assessment is to have students write a short paragraph answering these questions (you may want to tailor this to individual students who have special needs):
- What is a virus? What are its components/structure and how does it affect the human immune system?
- What is the difference between a virus and a bacterium?
- Identify three ways that viruses and infectious diseases can be transmitted to humans and from human to human contact.
- What are three infectious diseases?
- What are three ways that infectious diseases can be prevented?
- How does a vaccination work?
- How do antibiotics work on bacteria and why don’t they work on viruses?
These Science NetLinks lessons can be used to extend the ideas in this lesson:
What’s Back in Style?
Diseases that we thought went out of “fashion” have made a comeback. Have students go online to the sites listed in the lesson and find out which diseases we thought were eradicated but are reappearing, such as polio, whooping cough, resistant strains of tuberculosis, and cholera. There have been alarming reports in the news lately about diseases that are coming back because doctors and parents are forgetting or refusing to get their children vaccinated. Medical records are not updated.
Have students research why they are coming back, in which populations, in which geographic locations, and how they are spreading globally. What vaccinations are required in their state to enter and stay in school? How often should a person be re-inoculated to stay immune and safe?
Students should come up with some suggestions as to how we can combat them and contain the spread.