Why do sharks have high urea concentrations?

Idea's in Context Questions.?

• THESE ARE EXTREMELY LIKELY TO COME UP ON THE TEST OCR 21ST CENTURY ADDITIONAL SCIENCE, IDEAS IN CONTEXT. Additional Science Topic 1 1. What is meant by the term homeostasis? (2 mark) 2. What factors affect the production of urine in the body? (5 mark) 3. What substance will not be found in the urine of a healthy person? (1 mark) 4. What advice is given to dialysis patients? (2 mark) 5. What molecules can pass through the partially permeable membrane of the dialysis machine? (3 mark) 6. Why do red bloods remain in the patient’s blood during dialysis? (2 mark) 7. Why does the dialysis fluid flow in the opposite direction to the patient’s blood? (2mark) 8. Why is it important to keep the concentration of urea low in the dialysis fluid by constantly replacing it? (2 mark) 9. How many people in the UK population develop chronic kidney failure? (1 mark) 10. What scientific word is used to describe the movement of water molecules from area of high concentration to area of low concentration? (1 mark) 11. What hormone affects the production of urine? (1 mark) 12. Where is this hormone produced in the brain? (1 mark) 13. How does alcohol affect the production of urine? (2 mark) 14. What conditions might cause a person’s urine to be a) more concentrated b) more dilute. 15. What is the longest length of time a person may need to be attached to a dialysis machine in a week? 16. Proteins cannot pass through a partially permeable membrane, suggest why! 17. What does partially permeable mean? 18. Describe the affects of alcohol on the production of urine. Ensure you name the hormone responsible for controlling urine production in your answer. 19. Name two other things that are kept constant in the body via homeostasis. 20. Define reabsorption. Additional Science topic 2 The following words are continued throughput the passage. Give a definition for each word below. acid pH alkaline neutralise antacid compounds reactions carbonates concentrations ions insoluble soluble 2. What can be the result of having too much acid in the body? 3. What can happen as a result of having too much stomach acid? 4. What can happen as a result of having too much acid in our muscles? 5. What can happen if you have too much acid in the blood? 6. What two elements does a carbonate contain? 7. Looking at the table of results answer the following: (a) What variable was being investigated? (b) What variables were kept the same? (c) Do the results show a pattern? Explain. (d) Are the results precise? (e) Are the results reliable? Explain. (f) Explain why there may have been a slight change in temperature? (g) What conclusion could you draw from the results? (reference any results which support your conclusion) (h) Are there any obvious anomalies? (i) Suggest ways to make the results more precise? (j) Suggest ways to make the results more accurate? 8. Is it good to take tablets to neutralise stomach acid that are insoluble? Explain. 9. What are the side effects of insoluble neutralising stomach acid tablets? 10. What gas is made as result of taking insoluble neutralising stomach acid tablets? 11. What side effects of soluble neutralising stomach acid tablets? 12. What are the products of mixing an acid and an alkali together? 13. Which acid neutralising stomach acid tablet would you recommend? Explain. Additional Science topic 3 1. What happens when white light passes through a prism? 2. Why did the Royal Society publish Isaac Newton’s letter after he found out that light separated into different colours? 3. Why did Newton suggest that light was made of particles? 4. Christiaan Huygens established a wave theory of light in 1690. Why do you think that he waited until 1690 before he published his theory? 5. What was the advantage of Christiaan Huygens wave theory over Newton’s particle theory? 6. List the similarities and differences between TRANSVERSE and LONGITUDINAL waves. (Draw diagrams if it helps you to communicate your ideas) 7. Why did Thomas Young carry out many experiments on light? What did he discover? 8. What is the speed of light in a vacuum, in m/s and km/s? 9. James Clerk Maxwell calculated the speed of electromagnetic waves. What did he find out? What important conclusion did he state? 10. Heinrich Hertz supported Maxwell’s conclusion by carrying out experiments. Why is it important for other scientists to agree and arrive at the same conclusions? 11. Max Planck said that electromagnetic radiation arrives in small packets of energy. What are they called? 12. Planck also said that light behaved like waves and particles at the same time. What did this lead to? 13. What did Albert Einstein discover about electromag

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  9) James Clerk Maxwell said the "a small personage" operated a frictionless door.