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Page 2
Pumpkin Populations, and Limiting Factors
(student handout)
Name: Class: Date:
Exercise (A study of pumpkin population growth and limiting factors):
1. Obtain one small pumpkin per group of 3–4 students, one pumpkin carving tool, and some newspaper
for the lab tables.
2. Carefully cut out the top (stem end) of the pumpkin to expose the reproductive structures (seeds)
of the pumpkin.
3. Separate (scrape) all of the connective membrane containing the seeds from the interior of the pumpkin
to the paper on the lab tables, and then separate the seeds from the connective membrane for counting.
4. Assuming each individual seed can grow into a complete individual pumpkin plant, and a mature
pumpkin plant produces on average of 6 pumpkins (depending on variety, Jumbo usually 1–2, Regular
3–5, and Miniature as many as 12), calculate the number of pumpkins (offspring) your pumpkin could be
responsible for in generation two:
Number of seeds (offspring) in your pumpkin __________ x 6 Pumpkins from each mature plant =
__________ Pumpkins
Expected Results:
Actual seed counts will vary, but without fail students should get counted and calculated data that will
display exponential growth when graphed.
5. If the optimal distance for pumpkin plants to thrive is when they are planted 5 feet apart from every other
plant, what is the minimum amount of space needed (in square feet) to accommodate all of the offspring
from your particular pumpkin?
100 ft2 (if students calculate a square plat of land with each pumpkin plant in the dead center, 10' x 10')
78.5 ft2 (if students calculate circular plats of land with each pumpkin plant in dead center, 5'2 x 3.14)
6. Assuming all of the offspring plants produce the average number of pumpkins (6), and all of those pumpkins
have the same number of offspring (seeds) as your original pumpkin, how many pumpkin plants could be
possibly grown in generation three?
Answers will vary.
7. How much space (in square feet) would be needed to optimally grow generation three?
Answers will vary.
8. Continue the calculations for the fourth generation. How much space would be needed?
Answers will vary.
