The Acetate Animal Hunt

Carter, Linda DuSable High School

Objective: Students should be able to determine which variations (adaptations) would allow an organism to survive and reproduce in a certain environment. Apparatus needed: 25 clear acetate discs 25 yellow acetate discs 25 red acetate discs 25 blue acetate discs Discs should be about 1 cm in diameter. Recommended strategy: This activity uses acetate discs of different colors to determine which variations may help an organism to survive in a given environment. Use the entire floor area of the classroom as a habitat for a population of acetate "animals." These "animals" are all of the same species. The variation in the color of the discs representing the "animals" is due to different genetic inheritance. The following are the genotypes for each "animal." COLOR GENOTYPE clear ccrr red ccRR blue CcRr yellow CCrr Each individual in the class will act as a predator searching for food. The prey will be the acetate animals. They will be given 2 minutes to search the area for "food." Collect as many acetate animals as possible. When the time is up, reassemble and count the total number of acetate discs found by all members of the class. Chart your findings for each color disc. List number originally used, number found, number left on floor,and frequency of genes left. Students may prepare a bar graph indicating the frequency of color genes remaining in the acetate population. Determine gene frequency by dividing the total number of each color organism by the number of surviving organisms. Then multiply by 100 to find the percentage. Evaluation: 1. Which animals were most difficult to find? Explain. 2. Explain which acetate animals were the most fit? 3. Which were the most poorly adapted? Why? 4. What will eventually happen to genes of the most poorly adapted animals? 5. As far as the predators (you) are concerned, which of you will live and which of you will die? 6. List several factors that make the predators better adapted for hunting. Summary: 1. What does it mean for an organism to be adapted to its environment? 2. Explain the concept of "survival of the fittest." 3. Give the students several scenes in which they must determine which organisms within a population would most likely survive if their environment was to change. Have them explain why. Example: Imagine a population of species of giraffe living on an African plain for hundreds of years. Assume that the variation in this species is such that neck length ranges from short to very long. Most individuals have average-length necks, but some have short necks and some have very long necks. Assuming that this population of giraffes has been at genetic equilibrium for centuries, what would happen if another species, such as leaf-eating deer, entered the area? Would the species of giraffes change? NOTE: This paper has been modified from the original by the SMILE Staff.
Return to Biology Index