Problem:

Answer the following question given this paragraph:   Much of the time, you probably aren’t aware of your digestive system. It works well without causing any problems. But most people have problems with their digestive system at least once in a while. Did you ever eat something that didn’t “agree” with you? Maybe you had a stomachache or felt sick to your stomach. Perhaps you had diarrhea. These can be symptoms of food poisoning.   Q: Diarrhea due to food poisoning is an example of a problem involving what organ system?   A:
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A: digestive system


Problem:

Answer the following question given this paragraph:   Flame Cells of Planaria and Nephridia of Worms As multi-cellular systems evolved to have organ systems that divided the metabolic needs of the body, individual organs evolved to perform the excretory function. Planaria are flatworms that live in fresh water. Their excretory system consists of two tubules connected to a highly branched duct system. The cells in the tubules are called flame cells (or protonephridia) because they have a cluster of cilia that looks like a flickering flame when viewed under the microscope, as illustrated in Figure 41.10a. The cilia propel waste matter down the tubules and out of the body through excretory pores that open on the body surface; cilia also draw water from the interstitial fluid, allowing for filtration. Any valuable metabolites are recovered by reabsorption. Flame cells are found in flatworms, including parasitic tapeworms and free-living planaria. They also maintain the organism’s osmotic balance.   Q: How are valuable metabolites recovered?   A:
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A: reabsorption


Problem:

Answer the following question given this paragraph:   culture (outside the body under optimal growing conditions), the length of the cycle is about 24 hours. In rapidly dividing human cells with a 24-hour cell cycle, the G1 phase lasts approximately nine hours, the S phase lasts 10 hours, the G2 phase lasts about four and one-half hours, and the M phase lasts approximately one-half hour. In early embryos of fruit flies, the cell cycle is completed in about eight minutes. The timing of events in the cell cycle is controlled by mechanisms that are both internal and external to the cell.   Q: The timing of events in what cycle - which lasts just minutes in fruit fly embryos - is controlled by mechanisms that are both internal and external to the cell?   A:
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A: cell cycle


Problem:

Answer the following question given this paragraph:      Q: Abundant in unpolluted ponds and streams, planarians prey on smaller animals or feed on?   A:
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A: