Modeling Exponential Population Growth

B O N N I E  M C CO R M I C K

http://www.nabt.org/websites/institution/File/pdfs/american_biology_teacher/2009/May%20/071-05-0291.pdf

Student Protocol

1. Cut open the pepper and count the number of seeds inside. Record the total in Data Table 2 and on the SMARTboard so that a class total can be obtained. Assume that the number of bell peppers in the class represents the number of peppers produced by one bell pepper plant in a growing season.  Here is an example of a data table, make a blank one for your journal.

2. Record the total number of seeds counted for the class.

3. To complete the Data Table, assume that:

(a) Only one bell pepper plant existed the first year and that it produced the number of seeds represented by the class total.

(b) Each seed always grows into a new bell pepper plant the next year.

(c) Each new plant always produces the class total number of seeds.

(d) All pepper plants die at the end of the year.

4. Find the number of bell pepper plants that grow in the second year and record this number in Data Table 2. (Check with other groups and the teacher to make sure that this step is performed

correctly before continuing.)

5. Calculate the number of bell pepper plants that will grow in the second, third, and fourth years. Describe the method you used to calculate the number of plants for each generation. Write the

method as a mathematical equation.

6. Graph your results using the graphing calculator. Sketch your graph in your journal.

7. Answer the questions in Table 3 in your journal. Use Table 4 to help you answer the last 3 questions (look below Table 3).

8. Write-up requirements (look below Table 4)

Write-up Requirements for Human Population: (23 points)

1) Title  (reflecting independent and dependent variables). (1 point)

Using the last 3 questions of Table 3

2) Summary of results paragraph (include numbers) (3 points) and include a computer generated graph of the class peppers & human population with equation of the line. 

Show calculation for human population size in 2050 by using the equation of the exponential line OR state the size by using the actual graph. (1 point)

For more information on how to do the graphs  (6 points)

Logistic Growth Model

Exponential Growth Model

3) Conclusion paragraph: Answer the last 2 questions of Table 3. Remember to avoid pronouns. (cite sources within questions). (10 points)

4) References Cited (2 min using APA style www.bibme.org ) 2 points