Review Page 94 UNIT SUMMARY. Review Key Ideas and Vocabulary Suggested Answers. Time. Skills and Processes. Program Resources.

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Bonnie Wiggins
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Review Page 94 Time 45 60 min Skills and Processes The Unit Review provides an opportunity for students to demonstrate their understanding of and their ability to apply the key ideas, vocabulary, and

1 Review Page 94 Time min Skills and Processes The Unit Review provides an opportunity for students to demonstrate their understanding of and their ability to apply the key ideas, vocabulary, and skills and processes, and to demonstrate their ability to think critically. Program Resources BLM UA-1 Outline of the Human Body BLM UA Unit A Quiz Nelson Science Probe 8 Web site UNIT SUMMARY Make an overhead transparency of BLM UA-1 Outline of the Human Body, and project it on a large sheet of newsprint to trace a life-size outline. Have students complete BLM UA Unit A Quiz to review the vocabulary and concepts covered in Unit A. Review Key Ideas and Vocabulary Suggested Answers 1. (d) 2. (a) 3. (d) 4. (a) 5. (b) 6. (d) 7. (d) 8. When cells are in a solution in which the concentration of solute molecules is equal to the concentration of solute molecules inside the cell, there is equal movement of water into and out of the cell. The cell remains the same. When the concentration of solute outside the cell is higher than the concentration of solute inside the cell, water moves out of the cell by osmosis and the cell shrinks. When the concentration of solute outside the cell is lower than the concentration of solute inside the cell, water moves into the cell and the cell swells. If too much water enters, the cell will burst. 9. The term cell specialization refers to the process of cells developing to become specialized for a particular function. Specialized cells are very good at performing the tasks for which they are intended. They are not as good, however, at performing other cell functions. They must rely on cells that are specialized at performing these other functions. 10. The amoeba must perform all digestion within a single cell. Areas of the cell contain digestive enzymes that help to break down food. Absorption and excretion also take place inside the single cell. In multicellular animals, individual cells specialize to produce one specific group of enzymes. Other cells specialize for absorption or excretion. 11. The cells of the trachea have cilia that are similar to those of paramecia. The cilia of a paramecium beat in unison to move the paramecium through the water. The cilia on the surface of the lining 160 Unit A: Cells and Systems

2 of the trachea move substances over the surface of the cells. This is useful for preventing dust and bacteria from entering the lungs. The debris is moved up in the trachea, where it can be coughed up and expelled by spitting, or swallowed. The bacteria cannot survive in the very acidic conditions of the stomach. 12. (a) Organ name Number from Figure 1 (b) (i) E (ii) A (iii) D (iv) C (v) B (c) 1. (c) 2. (e) 3. (a) 4. (d) 5. (b) esophagus 4 kidney 7 lung 1 brain 9 intestine 6 heart 3 bladder 8 trachea 2 spinal cord 10 liver The atria and ventricles are the pumping chambers of the heart. The atria are smaller and have thinner muscular walls than the ventricles. The atria receive blood and pump it into the ventricles. The ventricles have thick muscular walls that enable them to pump the blood around the body. The right atrium receives deoxygenated blood from the body and pumps it into the right ventricle. The right ventricle pumps the blood to the lungs, where the blood picks up oxygen. The blood then returns to the left atrium. The left atrium pumps the oxygenated blood into the left ventricle, which then pumps it around the body. 14. The respiratory system depends on the circulatory system to deliver oxygen to the cells of the body and to collect carbon dioxide from the cells and deliver it to the lungs, where it is exhaled. Unit A Review 161

3 15. The valves in the heart keep the blood flowing in one direction through the circulatory system. 16. (a) A carbon dioxide B air C food D carbon dioxide E oxygen F food nutrients G food waste H cell waste I cell waste (or carbon dioxide) J carbon dioxide (or cell waste) K food nutrients (or oxygen) L oxygen (or food nutrients) M food waste N cell waste (b) The red arrows represent waste (carbon dioxide, cell waste, and food waste). (c) The blue arrows represent nutrients (oxygen and food nutrients). 17. The physical barriers of the primary line of defence include the skin, hairs, mucus, ear wax, tears, and chemicals (such as stomach acids). The skin covers the whole body and protects the inside of the body. In addition, it produces acidic oils and sweat that prevent microorganisms from growing. Hairs in the nostrils and ears prevent dust and dirt from entering the body. Mucus that covers the lining of the mouth, nose, and throat traps dust, dirt, and micro-organisms. 18. (a) Students diagrams should resemble Figure 6 on page 83 of the student book or Figure 7 on page 84. They should show a unique shape, which locks onto a toxin or a pathogen. (b) One kind of antibody does not provide immunity to more than one disease because each antibody is designed to fit the specific toxin or pathogen that causes the disease. toxins receptor site antibody Use What You ve Learned Suggested Answers 19. Bacteria and viruses may be passed from one person to another by direct or close contact (e.g., kissing, sexual contact, shaking hands, sneezing, coughing) or by disease vectors, such as insects (e.g., mosquitoes, ticks). 162 Unit A: Cells and Systems

4 20. The acidic gastric juices in the stomach do not digest the stomach itself because the stomach is protected by a layer of mucus that is secreted by the outside layer of cells of the stomach lining. 21. If the person drank only water to replace lost fluid, the concentration of solutes outside the cells would be less than the concentration of solutes inside the cells. Water tends to move into a cell to balance the concentration inside and outside the cell. When too much water enters a cell, it swells and ruptures. 22. (a) Students will probably recommend a wet mount as a technique for viewing these cells. (b) The cells are placed on a microscope slide, a couple of drops of water are added to the cells, and the cover slip is gently lowered over the cells. The cells are then suspended in the water between the cover slip and the slide. These cells can be examined under a microscope at low, medium, and high power. (c) All plant cells are not the same. Many, but not all, plant cells contain chloroplasts, which contain the green pigment chlorophyll. Onion skin cells would not contain chloroplasts because no photosynthesis takes place in the onion skin. Some plant cells are used only for structure and support. These would not necessarily contain chloroplasts or would contain fewer chloroplasts than the cells of a leaf. 23. When a cell is in a solution in which the concentration of solute molecules is equal to the concentration of solute molecules inside the cell, there is equal movement of water into and out of the cell. The cell remains the same. When the concentration of solute outside the cell is higher than the concentration of solute inside the cell, water moves out of the cell by osmosis and the cell shrinks. When the concentration of solute outside the cell is lower than the concentration of solute inside the cell, water moves into the cell and the cell swells. If too much water enters, the cell will burst. 24. The muscle surrounding the left ventricle of the heart is larger than the muscle surrounding the right ventricle because the left ventricle has to pump blood farther than the right ventricle. The left ventricle has to pump blood throughout the body, whereas the right ventricle has to pump blood only to the lungs. 25. The two-way flow of blood that can occur as a result of a heart murmur can create problems because the amount of blood flowing through the heart and throughout the body is reduced. This reduces the amount of oxygen that is being delivered to the cells of the body. Since the blood flow is reduced, the amount of carbon dioxide collected and delivered to the lungs is also reduced. Unit A Review 163

5 26. Look for the following in students investigations: A testable prediction and hypothesis: For example, a possible hypothesis might be If caffeine is added to the environment of a paramecium, then the organism s behaviour will change. Based on this hypothesis, a possible prediction is Adding caffeine to the environment of a paramecium will cause the paramecium to be more active (i.e., the paramecium will move more (or faster) than when no caffeine is present.) Identification of the independent, dependent, and controlled variables: The independent variable is the caffeine. The dependent variable is the amount (or rate) of movement of the paramecium. Students should also identify and control other variables (e.g., the amount of caffeine, the temperature of the water, the amount of light, the presence of food in the water) that might affect the dependent variable. Acknowledgement, explicit or implicit, of a control for comparison purposes: Students must acknowledge a situation in which no caffeine is added to the environment and all the other variables are kept constant. An operational definition of increased (or faster) movement: Students should devise a method of measuring or objectively describing the amount (or rate) of movement. A straightforward procedure that is clearly described in step-by-step fashion 27. (a) The pupil will constrict that is, it will become smaller. (b) The eye responds to changing light intensities by regulating the size of the pupil. The size of the pupil determines how much light enters the eye. In very bright conditions, the pupil will constrict, or become smaller, to reduce the amount of light entering. In very dim, or low light intensity, conditions, the pupil will dilate, or become larger, to allow more light to enter. 28. The primary or main function of the circulatory system is to transport oxygen from the lungs to the cells of the body and to collect carbon dioxide from the cells and deliver it to the lungs. The secondary function of the circulatory system is the defence of the body. In response to chemical signals released by invaders, specialized white blood cells are circulated to the site of an injury or infection to engulf and digest the invaders. 164 Unit A: Cells and Systems

6 Think Critically Suggested Answers 29. Students concept maps will vary. An example is given below: motor neurons red blood cells sensory neurons neurons blood cells white blood cells mitochondria CELLS eukaryotic cells ribosomes prokaryotic cells endoplasmic reticulum organelles Golgi apparatus lysosomes unicellular organisms bacteria protists fungi 30. Students will likely find that there are two types of artificial skin skin grown in culture from human skin cells and truly artificial skin made from synthetic materials. In skin tissue culture, a small piece of human skin is removed and placed in a proper medium, where it will continue to grow. A laboratory in Australia claims that, from a piece of skin 2 cm 2 cm, enough skin can be grown in three weeks to cover a whole person. The most common use of cultured skin is in the treatment of burn victims. The development of synthetic skin eliminates the need to harvest healthy skin from another part of the body of a burn victim. Synthetic skin is produced from biopolymers and natural products, such as collagen and shark cartilage. 31. Students suggestions for ways to improve respiratory and circulatory health should fall into one or more of the following categories: identifying the risk factors eating healthier managing stress becoming more physically active losing weight and/or maintaining healthy weight stopping smoking becoming knowledgeable (getting proper information) Unit A Review 165

7 32. If humans lacked a nervous system, they would not be able to control their internal environment or respond to their external environment. Without a nervous system, humans simply could not exist. The nervous system allows us to identify and obtain food, and to identify and avoid dangerous situations. Controlled movement would not be possible without a nervous system, because the nervous system controls the movements of muscles. 33. Conditions such as asthma are dangerous because they cause inflammation and swelling of the tissue lining the lungs. This inflammation and swelling prevents the proper exchange of gases in the lungs. Insufficient oxygen is absorbed, and carbon dioxide cannot be expelled efficiently. These conditions would affect any activity that involved physical exertion, such as walking or running. Physical activities require the use of muscles. Muscle cells require oxygen in order to function properly, and they need to get rid of carbon dioxide and other wastes. If sufficient oxygen cannot be obtained through the lungs, any physical activity will become more difficult. 34. (a) Students answers will vary. Many students will likely agree with mandatory urine testing for people in responsible positions (e.g., police officers, airline pilots, ship captains, firefighters, medical professionals). (b) Students answers will vary. Most students will likely take the position that professional athletes should undergo mandatory drug testing. Their arguments will probably be based on the idea that highly paid professional athletes should rely on their natural abilities rather than on the unfair advantage that drugs provide. Students may compare drug use to cheating on exams. 35. Students will likely identify peer pressure as the reason why someone would start smoking and will likely suggest advising the friend to resist the pressure and do what is best for him/herself. It is possible, however, that some students will claim that such a decision is a personal choice and no one else has the right to question another s decision. Reflect on Your Learning Suggested Answers 36. The statement all for one and one for all is a reference to the interdependence of the body systems of large, multicellular organisms. Students answers should emphasize this interdependence. 37. Students answers will vary. Look for the following ideas: a sense of amazement at the complexity of the human body examples of the complexity (e.g., the continuous, rhythmic beating of the heart; the specialization of cells, tissues, and organs for specific functions) evidence of the students respect for their body (as demonstrated by their lifestyle choices) 166 Unit A: Cells and Systems

8 ESL Allow ESL students to answer a representative sample of questions orally. Have students work with a bilingual partner to answer the questions, but require individual answers. Meeting Individual Needs Extra Support Under special circumstances, consider providing an opportunity for students to answer a sample of these questions orally. Select questions from each category. Extra Challenge The Reflect on Your Learning questions can be adapted or extended as additional research projects for students who are able and interested. Challenge students to create a crossword puzzle based on the vocabulary, concepts, and key ideas in the unit, using a program on the Internet. Unit A Review 167

Science 8 - Cells & Cell Organization Notes

Science 8 - Cells & Cell Organization Notes 1.1 - Characteristics of Living Things Composed of cells Reproduce, grow & repair themselves Require energy o Plants usually from sun o Animals from plants or