Tr7 Worksheet u1 indd
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- Worksheet 1.2 Cambridge Checkpoint Science 7
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Copyright Cambridge University Press 2012 Cambridge Checkpoint Science 7 Each plant organ has a particular function or functions. Here is a list of functions. absorbs water absorbs energy from sunlight holds plant in the soil makes food makes seeds for reproduction supports leaves and flowers Write each of these functions in the correct box on the diagram. (Some boxes may contain more then one function.) 1 Worksheet 1.1 Copyright Cambridge University Press 2012 Cambridge Checkpoint Science 7 The diagrams show some of the organs in the human body. 1 Colour each of the organs according to the organ system to which it belongs. respiratory system green digestive system yellow nervous system blue circulatory system red 2 Cut out each organ. Copyright Cambridge University Press 2012 Cambridge Checkpoint Science 7 3 On one of the outlines of the human body (on page 3), stick the organs belonging to the respiratory system and digestive system in the correct positions. (You’ll need to stick some of the organs over the top of others.) 4 On the other outline of the human body (on page 3), stick the organs belonging to the nervous system and circulatory system in the correct positions. Copyright Cambridge University Press 2012 Cambridge Checkpoint Science 7 Blank page in case of two-sided printing Copyright Cambridge University Press 2012 Worksheet 1.2 Cambridge Checkpoint Science 7 Read the information about arthritis. Then answer the questions. Many people get arthritis as they get older. Arthritis makes joints feel painful and stiff. Arthritis happens when the cartilage covering the bones at a joint gets damaged. It becomes rough, instead of being smooth and slippery. Sometimes, the cartilage is so badly damaged that it does not cover the ends of the bones. Each time the bones move, they rub against each other. The joints that are most often affected are the knees, fingers and hips. Artificial joints are sometimes used to replace damaged joints. Artificial joints are made of metal and plastic. One metal that is often used is titanium. This metal does not react with the fluids inside the body. The surfaces of the artificial joints are very smooth. 1 Describe what happens to a joint to cause arthritis. 2 Explain why arthritis makes it more difficult to move a joint. Copyright Cambridge University Press 2012 Osteoarthritis initially affects the smooth cartilage lining of the joint . This makes movement more difficult than usual, leading to pain and stiffness. Once the cartilage lining starts to roughen and thin out, the tendons and ligaments have to work harder. 3 Explain why titanium is used to make artificial joints. Because they show excellent corrosion resistance and good hard-tissue compatibility (bone formation and bone bonding ability) 4 Explain why the surfaces of artificial joints must be very smooth. The main reason for replacing any arthritic joint with an artificial joint is to stop the bones from rubbing against each other. This rubbing causes pain. Cambridge Checkpoint Science 7 Yüklə 446,95 Kb. Dostları ilə paylaş:
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