DNA Profiling Gizmo Answer Key

Name: Lillie Stark Date: 11-17-2022 Student Exploration: Disease Spread Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: contagious, disease, epidemic, infect, infectious disease, pathogen Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Why do you think it is important to cover your mouth when you cough? so that the illness or disease you have doesn't spread 2. Why should you always wash your hands before you eat? to avoid handling your meals with filthy hands. Gizmo Warm-up When a person has a disease, his or her normal body functions are disrupted. Some diseases, such as diabetes and most cancers, are not spread from one person to another. But other diseases, such as the flu and strep throat, can be spread. These diseases are known as infectious diseases. Infectious diseases are caused by viruses, bacteria, and other agents known as pathogens. In the Disease Spread Gizmo, you will be able to observe how various pathogens can spread through a group of students in a school. Click Play ( ) and observe. 1. Describe what happened on the SIMULATION pane: around time, the illness spread all over the room. 2. Look at the color key on the bottom right of the Gizmo. What is happening when a person changes color? when he changes color, he is infected. Activity A: Person-to-person transmission Get the Gizmo ready: ● Click Reset ( ). ● On the CONTROLS tab, select Person to person. ● Set the Number of people to 10. Question: What factors affect how quickly a pathogen spreads from person to person? 1. Predict: Some pathogens are spread directly from one person to another. This can happen when people come into direct contact or share items, such as drinking glasses. What do you think might affect how quickly a pathogen is spread from person to person? if it is trying to be controlled or not. 2. Identify: Select the TABLE tab. (You will want the table tab open to answer question C.) A. What does the orange person represent? between individuals B. Click Play, and observe the simulation for a while. What must happen for the disease to spread from one person to another? the infection must spread C. How long did it take to infect all ten people? 80 hours 3. Experiment: Click Reset. Change the Number of people to 20. Click Play and record how long it takes to infect 10 people. Repeat this four times for a total of 5 trials, then calculate the mean time. Repeat the experiment when there are 30 people and 40 people in the room. Number of people 20 30 40 Time to infect 10 people, 5 trials (h) 4 hours 10 hours 18 hours Mean time (h) 4 hours 10 hours 18 hours 4. Interpret: Study the data you collected. What trend do you see in the data, and how would you explain it? every time, the 10 persons were affected more quickly. 5. Experiment: Not all pathogens are equally contagious, or likely to spread. The probability of transmission is the chances that a contact between two people will result in transfer of the disease. Click Reset and set the Number of people to 20. Set the Probability of transmission to 20%. Record data for transmission probabilities of 20%, 50%, and 80%. Transmission probability 20% 50% 80% Time to infect 10 people, 5 trials (h) 2 hours 6 hours 8 hours Mean time (h) 2 hours 6 hours 8 hours 6. Interpret: Study the data in the table. What trend do you see, and how would you explain it over time, the effects on people became less pronounced. 7. Experiment: For certain pathogens, mask-wearing can greatly reduce the probability of transmission. Click Reset, select Students wearing masks, and set the Probability of transmission (without masks) to 50%. Check that the Number of students is still 20. Run five trials with masks and find the mean time to infect 10 people. Probability (without masks) 50% Time to infect 10 people, 5 trials (h) Mean time (h) 20 4 8. Compare: Compare the mean time to infect ten people with masks to the mean time to infect ten people without masks. (Use the 50% line from the table in question 5.) How do these times compare? sans masks, roughly twice as quick 9. Infer: Why do you think masks have this effect on the rate at which a person-to-person disease spreads? it helps stop the sickness 10. Think and discuss: Suppose you were a public health official. Based on the data you have collected, how would you slow the spread of a person-to-person disease? I would require masks Activity B: Foodborne transmission Get the Gizmo ready: ● Click Reset. Select Foodbourne. ● Set the Number of people to 10 and the Probability of transmission to 100%. Introduction: Many types of food, especially meat or fresh produce, can be infected with pathogens. A foodbourne disease is spread when people eat or drink infected food or water. One way to avoid these diseases is to boil drinking water and thoroughly cook meats. Question: How do foodborne pathogens spread? 1. Predict: How do you expect the spread of a foodborne disease to be similar to and different from the spread of a person-to-person disease? I anticipate it to be rather similar. 2. Observe: Click Play and closely watch the students moving around the cafeteria. A. What does each student do before becoming infected? they change color to orange B. How are foodborne pathogens transmitted? via ailments C. If a student in the simulation never eats or drinks anything from the buffet table, is it possible for them to become sick with the foodborne disease? Explain. yes, if they never eat or drink, they can, in fact, contract a foodborne illness. 3. Experiment: Click Reset. Change the Number of people to 20. Click Play and record how long it takes to infect 10 people. Repeat this four times for a total of 5 trials, then calculate the mean time. Repeat the experiment when there are 30 people and 40 people in the room. Number of people 20 30 40 Time to infect 10 people, 5 trials (h) 3 hours 6 hours 20 hours Mean time (h) 6 hours 7 hours 22 hours 4. Interpret: What trend do you see in your data? Why do you think this is the case? People are being impacted more quickly than person to person. 5. Experiment: Set the Number of people to 20. Using the same method, find the mean time for each transmission probability. Transmission probability 20% 50% 80% Time to infect 10 people, 5 trials (h) 4 hours 6 hours 8 hours Mean time (h) 3 hours 7 hours 10 hours 6. Interpret: Study the data you collected. What trend do you see in the data, and how would you explain it? the people are not getting affected quickly at all 7. Experiment: Click Reset. Select Students wearing masks and set the Probability of transmission (without masks) to 50%. Check that the Number of students is still 20. Using the same method as before, collect data to see the effect of masks. Probability (without masks) 50% Time to infect 10 people, 5 trials (h) Mean time (h)