LOGO - PULSE



Does the Chicken have Anthrax (Explain I)

By Dean Johnson from http://www.aai.org/committees/education/Curriculum/DeanJohnson.pdf
Modified to fit the PULSE curriculum



Time: 2 class periods
Preparation Time:  
Materials:

6 groups of students, with each group receiving the following:
* 1 apple or hardboiled egg
* 1 plastic knife
* 1000mL beaker filled with 500mL of water and 10 drops of food coloring(color can vary)
* vinegar
* lukewarm water
* hot water
* 3-5 grams of sugar
* yeast
* zip lock bags

Abstract
The purpose of this activity is for the students to develop an understanding for the components of nonspecific immunity by utilizing a scientific approach. This activity addresses three different defenses that are incorporated into innate immunity. In addition, the exercise allows the students to develop an appreciation for this concept utilizing yeast as a model organism.

Objectives
Students will be able to:

i. Explain how each of the components of innate immunity function in the protection of the body.
ii. Following an investigation, articulate how innate immunity functions.

National Science Education Standard:
Content Standard A – Science as Inquiry
Content Standard C – Life Science
THE CELL
Cells have particular structures that underlie their functions. Every cell is surrounded by a membrane that separates it from the outside world. Inside the cell is a concentrated mixture of thousands of different molecules which form a variety of specialized structures that carry out such cell functions as energy production, transport of molecules, waste disposal, synthesis of new molecules, and the storage of genetic material.
Cell functions are regulated. Regulation occurs both through changes in the activity of the functions performed by proteins and through the selective expression of individual genes. This regulation allows cells to respond to their environment and to control and coordinate cell growth and division.

Teacher Background

Innate immunity is the first line of defense against pathogens and is an evolving system of protection that works in cooperation with adaptive forms of immunity. This activity addresses three different defenses that are incorporated into innate immunity. The first nonspecific defense that this activity examines is skin. The students can develop an understanding for the role skin has within the body’s immune system with the use of hard boiled eggs or apples and water with food coloring in it. The apple skin and hard eggshell offer protection to the apple and egg that is analogous to that of the skin and our bodies.

A second defense offered by innate immunity is a fever. The human body, under normal conditions, maintains an internal temperature of 98.6 degrees Fahrenheit. The body is, however, capable of generating an immune response that intentionally raises the internal temperature that results in a fever. This is one example of an innate immune response that helps the immune system defend the body against pathogens. This activity allows the students to develop an appreciation for this concept utilizing yeast, sugar, and water. Yeast is a unicellular organism that utilizes alcoholic fermentation in order to generate energy. The temperature of the yeast’s environment, however, significantly affects this process. Yeast does not grow at temperatures between 0– 10 degrees Celsius and dies at temperatures above 50 degrees Celsius. The optimal growth rate for yeast occurs between 30 – 37 degrees Celsius.

Many organisms, such as yeast, also are influenced by the pH of their environment. Yeast grows well in solutions whose pH is neutral or mildly acidic. The third portion of this activity allows the students to observe the effects that vinegar (whose pH is approximately 3.5) has on the growth of yeast. This activity can be used to discuss the roles that sweat and body oils have in the immune system.

Related and Resource Websites
http://www.aai.org/committees/education/Curriculum/DeanJohnson.pdf

 

Activity

1. Anticipatory set for this activity is the question: Are chickens susceptible to anthrax? (The answer is no, because their body temperature is too high (41 – 45 degrees Celsius) for the anthrax to survive. The body temperature of humans is 37 degrees Celsius. The students will not be given the answer until they complete the activity.

2. The class will be divided up into 6 groups of four and given instructions for how the activity will proceed.

3. Each group will be given an apple and a freshly cut section of an apple. They will also be supplied with a 1000mL beaker filled with 500mL of water and 10 drops of food coloring.

4. The first segment of this investigation is for the students to place the whole apple and the freshly cut section in the beaker for 10 minutes (while they are waiting they can set up the other experiment involving the yeast). The purpose of this activity is to determine how these two apples will be affected when they are placed in the beaker.

5. The students will be asked to form a hypothesis based upon prior observations outside the class, write the procedure and record their observations (the students can use a plastic knife in order to cut into the apples and make better observations).

6. The students must record their observations and note whether the whole apple and the cut-up section experiences any color change. Students should address whether their initial hypothesis was supported or rejected.

7. The second portion of this activity requires students to determine the effects that temperature and pH have on yeast mortality (the students must first have an understanding of cellular respiration and alcoholic fermentation).

8. Each group will be given 3 zip lock bags with an equal amount of yeast and sugar in them.

9. They will be asked to collect 100mL of boiling water from the hot water bath using a 250mL beaker with the instructor’s assistance. They will also collect 100mL of lukewarm water from a water bath that is regulated at 80 degrees Fahrenheit plus 100mL of vinegar.

10. Each of these beakers will be poured carefully into one of each of the zip lock bags, and the bags will then be sealed.

11. After 10 minutes have elapsed; the students will make observations about the viability of the yeast on these three bags. Cellular respiration hopefully was covered earlier in the year, but if not this would be an opportunity to begin to introduce it.

12. After all of their observations and conclusions have been recorded, the groups will share their results as a class.

13. This discussion will be used to develop an understanding for innate immunity and its four component defenses which are: anatomic barriers (skin and mucous), physiologic barriers (temperature, pH, and chemical mediators), phagocytic barriers (specialized cells), and inflammatory barriers (leakage of vascular fluids). Guide the discussion to address the connection between the exercises that the students performed and the four component defenses of innate immunity.

Closure

The students will be reminded of the question they were asked at the beginning of the class regarding chickens and their susceptibility to anthrax. Chickens have evolved in such a way that they have innate immune protection against anthrax because their body temperature is too high for anthrax to survive.

Embedded Assessment

 

 


PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:


an
NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award

LOGO - SWEHSC
LOGO - NIEHS Center LOGO - NIEHS

Supported by NIEHS grant # ES06694


1996-2007, The University of Arizona
Last update: November 10, 2009
  Page Content: Rachel Hughes
Web Master: Travis Biazo