Higher Level Questions on Homeostasis Section A SEC Sample Paper HL 6. The graph shows the variations in human body temperature over a number of days. What was the minimum temperature recorded? ............................................................ What was the maximum temperature recorded?............................................................ Suggest a reason for the difference between body temperature during period X and the same period on the previous days........................................................................................... What is the source of the heat that keeps the body at a fairly constant temperature? State two responses that result when body temperature begins to drop. Explain briefly how sweating assists in the shedding of excess heat . 2011 HL 4. (a) (b) (i) What is an endotherm? (ii) What word is used to describe animals which are not endotherms? (iii) Suggest an advantage of being an endotherm. The graph shows daily variations of human body temperature over three days. DAY 1 DAY 2 DAY 3 (i) What is the maximum range of body temperature under normal conditions as shown in the graph? (ii) At what time each day does body temperature drop to its lowest level? (iii) Suggest a reason for the drop in temperature at the time referred to in (ii). (iv) Children typically have higher body temperatures than adults. Suggest a reason for this. Higher Level Section C 2004 HL 12. (a) What is homeostasis? State the role of the kidneys in homeostasis. (9) 2007 HL 15. (c) (i) What is homeostasis? Note one reason why it is important in the human body. Draw a diagram of a section through human skin to show two structures involved in temperature regulation. Label each of these structures. (iii) For one of the structures that you have labelled in your diagram briefly describe its role in temperature regulation. (iv)What is meant by an ectotherm? [30] (ii) 2009 HL 15. (c) Write notes on three of the following topics: (iii) Homeostasis. 20120 HL 15. Answer any two of (a), (b), (c). (30, 30) (c) (i) Explain the term homeostasis. (ii) Homeostasis often requires an organism to exchange materials between different tissues, or between itself and the external environment by diffusion, osmosis, and active transport. Explain each of the underlined terms. (iii) State one way in which each of the following contributes to homeostasis. 1. Liver. 2. Lungs. 3. Nephrons of kidneys. (iv) Describe the role of the skin in controlling body temperature. Ordinary Level Section C 2012 OL 15. Answer any two of the parts (a), (b), (c). (30, 30) (a) The diagram shows a section through human skin. (i) Name the parts labelled A, B, and C. (ii) The skin is one of the excretory organs in humans. Name one substance excreted by the skin. (iii) List two other functions of the skin. (iv) Name another organ of excretion and state one substance it excretes. (iv) What is meant by the term homeostasis? (vi) The human being is an endotherm. What does this mean?