AP Biology Lab 11: Roly Poly Enhanced Interrogation Animal Behavior1 Overview In this lab you will observe the behavior of pill bugs and design an experiment to investigate their responses to environmental variables. Objectives Before doing this lab you should understand: 1. The concept of distribution of organisms in a resource gradient, and 2. The difference between kinesis and taxis. After doing this lab you should be able to: 1. describe some aspects of animal behavior, such as orientational behavior, agonistic behavior, dominance display, or mating behavior, and 2. Understand the adaptiveness of the behaviors you studied. 3. How to quantitively analyze your results using chi-square. Introduction Ethology is the study of animal behavior. Behavior is an animal’s response to sensory input and falls into two basic categories: learned and innate (inherited). Orientation behaviors place the animal in its most favorable environment. In taxis, the animal moves toward or away from a stimulus. Taxis are often exhibited when the stimulus is light, heat, moisture, sound, or chemicals. Kinesis is a movement that is random and does not result in orientation with respect to a stimulus. If an organism responds to bright light by moving away, that is taxis. If an organism responds to bright light by random movements in all directions, that is kinesis. Agonistic behavior is exhibited when animals respond to each other by aggressive or submissive responses. Often the agonistic behavior is simply a display that makes the organism look big or threatening. It is sometimes studied in the laboratory with Bettas (Siamese fighting fish). Mating behaviors may involve a complex series of activities that facilitate finding, courting, and mating with a member of the same species. Part A: General observation of behaviors In this lab you will be working with terrestrial isopods commonly known as pill bugs, sow bugs, wood lice (unrelated to human lice) or roly-poly’s. These organisms are members of the Phylum Arthropoda, Class Crustacea, which also includes shrimp and crabs. Pill bugs (as they will now be referred to) are the only crustaceans that are terrestrial. Pill bugs are completely harmless. 1 Adapted from the College Board AP Biology Student Lab Manual, 2001 edition. AP Biology Procedure 1. Place 10 pill bugs and a moist filter paper disk in a Petri dish. Pill bugs generally do not climb, but if they do, you may cover the dish to keep them inside. 2. Observe the pill bugs for 10 minutes. Use the magnifying glass to aid you. Make extensive notes on their appearance, movements about the dish, and interactions with each other. Notice if they seem to prefer one area over another, if they keep moving, settle down, or move sporadically. Note any behavior that involves more than one pill bug. Try to make your observations without disturbing the pill bugs in any way. Do not prod, poke, or shake the dish, make loud sounds, or subject them to bright lights. Your job is to observe their behavior, not influence it. Use the full 10 minutes to notice as much as you can. 3. Make a detailed sketch of a pill bug. Your sketch should have a title and should have notes as appropriate. Part B: Kinesis in Pill bugs 1. Write a hypothesis AND a null hypothesis that makes a prediction about the pill bugs’ behavior in this experiment. Use an “if, then, because” format for both hypothesis. 2. Set up a data table that allows you to record numbers and comments every 0.5 minute for 10 minutes. Include a zero time point. Procedure 1. Obtain a choice chamber with two connected chambers. Line one chamber with a moist piece of filter paper and the other with a dry piece of filter paper moistened with 1% Hydrochloric Acid. (Apply about 5- 10 drops to each side. The filter paper should be moist, but not wet.) The filter paper should lie flat so that pill bugs will not crawl underneath it. 2. Use a soft brush to transfer 5 pill bugs from the stock culture into the moist side of the choice chamber and 5 into the treated side. Why are both sides moistened? Why not use dry filter paper on the untreated side? 3. Count how many pill bugs are in each side of the choice chamber every 30 seconds for 10 minutes. Continue to record even if they stop moving. 4. Also make note of any significant behaviors. 5. Return the pill bugs to the stock culture. Part C: Student-Designed Experiment In this section of the lab, you will be performing an experiment similar to the one you performed in Part B, but you will test a different variable and design the experiment with your partner(s). You may test the effect of pH, solutes, light, color, surface texture, or temperature. The following materials will be available: filter paper, water, vinegar, mild base, thick paper to block light, light, sandpaper, salt water. You may provide any materials for your lab that are not listed. AP Biology Journal Assignment: 1. Decide what variable you want to test and how you will control other possible variables. a. One section of the chamber will be the test; the other chamber will be the control. 2. Write your objective for the experiment in your lab notebook. Be specific. 3. Sketch the chamber and describe your experiment in detail. Explain how you intend to test your variable. Identify the critical parts of the experiment by captioning your chamber diagram. This will be done in your journal as a separate assignment. a. This will be due, and must be approved, before this part of the lab is started. Procedure 1. During lab time (day 2), and after you have completed Part B, perform your experiment, using the same procedure as Part B, including the hypothesis (including a null) and chi square test. 2. Return your isopods to the stock culture. Data Analysis 1. Analyze your results for both tests using chi-square. Be sure to analyze the results with a .05 certainty. SHOW YOUR WORK. 2. Include a table for both tests 3. Include an appropriate graph for both tests General Outline for this Lab (See formal lab report guidelines) 1. Title 2. Abstract 3. Intro a. describe the pill bug’s behavior, taxonomy and general characteristics (including sketch of pill bug) b. Description of taxis, kinesis and ethology c. General description of what is being tested 4. Hypothesis and Prediction (both tests, including null hypothesis) 5. Procedure (both tests) 6. Analysis (both tests) a. data tables b. graph including both tests c. chi-square 7. Conclusion a. Accept or reject hypothesis based on critical values (.o5) b. rationale for acceptance or rejection of tests, and a discussion of the following: description of your lab set up, including control, behavior AP Biology exhibited, discussion of your results, why this occurred, type of behavior (taxis, kinesis, agonistic), cause of behavior (chemo, photo, gravi, etc.) c. potential errors/ ways to improve the lab 8. Bibliography – APA Format .