7 click the test your understanding button in the

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[ 7 ] Click the TEST YOUR UNDERSTANDING button in the lower right and answer the question. This exercise demonstrated one possibility for using the Experimental Lakes . In the next exercise you will be introduced to another powerful tool: Experimental Tanks .
SimBio Virtual Labs ® | Top-Down Control © 2020, SimBio. All Rights Reserved. 11 Exercise 4. Experimental Tanks Experimental Lakes are useful for studying large-scale questions. In contrast, you will see that Experimental Tanks are particularly useful for short-term experiments on one or a small number of individual organisms at a time. They mimic the controlled laboratory setups ecologists might use, for example, to study food preference, feeding rate, and other aspects of individual behavior. To mimic the conditions of these short-term experiments, the organisms you add to your tanks will neither reproduce nor die. In addition, phytoplankton in the Experimental Tanks do not move. Remember this as you design your experiments! Your Experimental Tools [ 1 ] Select Experimental Tanks from the SELECT AN EXERCISE button in the upper left-hand corner of the screen. [ 2 ] Examine the Tools panel at the bottom of the screen. As with the previous exercise, you can add individuals to the tank in any combination and examine gut contents. Observe the Time Elapsed box. Your experiments last only a few hours rather than weeks. [ 4 ] For short-term experiments, you might want to take advantage of the STEP 1 button on the Control Panel . This moves the simulation forward one hour at a time. You can use this feature, for example, to follow the feeding behavior of one individual over time. [ 5 ] To clean out your experimental tank and start over with a new experiment, click the RESET but- ton on the Control Panel . Your Experiments What you do with these tools will depend on the questions prompted by your previous experiments, observations, and findings. Again, to familiarize you with the setup, here is one example of something you could do in an Experimental Tank . To give you an idea of how you can use the experimental tank to study behavior, you will conduct a study to determine how long it takes an individual Daphnia to catch a green algae cell. [ 1 ] Add one green algae cell to the tank, and add one Daphnia right next to it. [ 2 ] Click the MICROSCOPE button so that you can examine gut contents. [ 3 ] Advance the model one time-step by clicking on the STEP 1 button. [ 4 ] If the green algae disappears, click on the Daphnia and see if it has anything in its gut. If not, keep advancing the model one hour at a time until the Daphnia’s gut shows that it ate algae. [ 4.1 ] Record the number of time-steps required for the Daphnia to eat the algae. 122 hours
SimBio Virtual Labs ® | Top-Down Control © 2020, SimBio. All Rights Reserved. 12 [ 5 ] That particular Daphnia may have been especially lucky or unlucky while you were watching it and caught its food either faster or slower than normal. Therefore, you should always repeat your behavioral experiments multiple times and determine the average result (i.e., repeat steps 1

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