BIOL1. General Certificate of Education Advanced Subsidiary Examination January Unit 1 Biology and disease

Transcription

1 Centre Number Surname Candidate Number For Examiner s Use Other Names Candidate Signature Examiner s Initias Bioogy Genera Certificate of Education Advanced Subsidiary Examination January 2011 BIOL1 Question Mark Unit 1 Bioogy and disease Tuesday 11 January am to am For this paper you must have: a ruer with miimetre measurements a cacuator TOTAL Time aowed 1 hour 15 minutes Instructions Use back ink or back ba-point pen. Fi in the es at the top of this page. Answer a questions. You must answer the questions in the spaces provided. around each page or on bank pages. You may ask for extra paper. Extra paper must be secured to this booket. Do a rough work in this book. Cross through any work you do not want to be marked. Information The marks for questions are shown in brackets. The maximum mark for this paper is 60. You wi be marked on your abiity to: use good Engish organise information ceary use scientific terminoogy accuratey. BIOL1

2 2 Answer a questions in the spaces provided. 1 The diagram shows a choera bacterium. It has been magnified times. A B C 1 (a) Name A. 1 (b) Name two structures present in an epitheia ce from the sma intestine that are not present in a choera bacterium (c) Choera bacteria can be viewed using a transmission eectron microscope (TEM) or a scanning eectron microscope (SEM). 1 (c) (i) Give one advantage of using a TEM rather than a SEM. 1 (c) (ii) Give one advantage of using a SEM rather than a TEM. (02)

3 3 1 (d) Cacuate the actua width of the choera bacterium between points B and C. Give your answer in micrometres and show your working....µm 1 (e) An outbreak of choera occurred in London in The graph shows the reationship between the number of deaths from choera and the height at which peope ived above sea eve Number of deaths per from choera Height above sea eve / m Describe the reationship between the number of deaths from choera and the height at which peope ived above sea eve. 9 Turn over (03)

4 4 2 (a) Induced fit and ock and key are two modes used to expain the action of enzymes. 2 (a) (i) Describe the induced fit mode of enzyme action. 2 (a) (ii) Describe one way that the ock and key mode is different from the induced fit mode. (04)

5 5 2 (b) Foic acid is a substance required by bacteria for ce growth. Bacteria produce foic acid by the foowing reaction. para-aminobenzoic acid (PABA) enzyme foic acid The diagram shows the structure of a moecue of PABA. It aso shows the structure of a moecue of a drug caed sufaniamide, which can be used to treat bacteria infections. Sufaniamide prevents bacteria producing foic acid. PABA CO 2 H sufaniamide SO 2 NH 2 NH 2 NH 2 Use the diagram and your knowedge of enzymes to expain how sufaniamide prevents bacteria producing foic acid. (3 marks) (Extra space)... 6 Turn over (05)

6 6 3 The diagram shows a human heart as seen from the front. The main bood vesses are abeed D to G. The arrows show the pathways taken by the eectrica activity invoved in coordinating the heartbeat in the cardiac cyce. E F Semiunar vaves Sinoatria node (SAN) D G Atrioventricuar node (AVN) 3 (a) Which of the bood vesses, D to G 3 (a) (i) carries oxygenated bood to the heart 3 (a) (ii) carries deoxygenated bood to the ungs? 3 (b) Expain, in terms of pressure, why the semiunar vaves open. (06)

7 7 3 (c) When a wave of eectrica activity reaches the AVN, there is a short deay before a new wave eaves the AVN. Expain the importance of this short deay. 3 (d) The tabe shows the cardiac output and resting heart rate of an athete before and after competing a training programme. Cardiac output / cm 3 Resting heart rate / beats per minute Before training After training (d) (i) Cacuate the athete s stroke voume after training. Show your working....cm 3 3 (d) (ii) Use information from the tabe to expain how training has caused the resting heart rate of this athete to be ower. 9 Turn over (07)

8 8 4 (a) Omega-3 fatty acids are unsaturated. What is an unsaturated fatty acid? 4 (b) Scientists investigated the reationship between the amount of omega-3 fatty acids eaten per day and the risk of coronary heart disease. The graph shows their resuts Risk of coronary heart disease Amount of omega-3 fatty acids eaten per day / g Do the data show that eating omega-3 fatty acids prevents coronary heart disease? Expain your answer. (3 marks) (08)

9 9 4 (c) Oestra is an artificia ipid. It is made by attaching fatty acids, by condensation, to a sucrose moecue. The diagram shows the structure of oestra. The etter R shows where a fatty acid moecue has attached. CH 2 OR H H ROCH 2 H RO OR H O X H RO CH 2 OR H OR OR H 4 (c) (i) Name bond X. 4 (c) (ii) A trigyceride does not contain sucrose or bond X. Give one other way in which the structure of a trigyceride is different to oestra. 4 (c) (iii) Starting with separate moecues of gucose, fructose and fatty acids, how many moecues of water woud be produced when one moecue of oestra is formed? 8 Turn over (09)

10 10 5 A student investigated the effect of putting cyinders cut from a potato into sodium choride soutions of different concentration. He cut cyinders from a potato and weighed each cyinder. He then paced each cyinder in a test tube. Each test tube contained a different concentration of sodium choride soution. The tubes were eft overnight. He then removed the cyinders from the soutions and reweighed them. 5 (a) Before reweighing, the student botted dry the outside of each cyinder. Expain why. The student repeated the experiment severa times at each concentration of sodium choride soution. His resuts are shown in the graph Mean percentage change in mass Concentration of sodium choride soution / mo dm -3 (10)

11 11 5 (b) The student made up a the sodium choride soutions using a 1.0 mo dm -3 sodium choride soution and distied water. Compete the tabe to show how he made 20 cm 3 of a 0.2 mo dm -3 sodium choride soution. Voume of 1.0 mo dm -3 sodium choride soution Voume of distied water 5 (c) The student cacuated the percentage change in mass rather than the change in mass. Expain the advantage of this. 5 (d) The student carried out severa repeats at each concentration of sodium choride soution. Expain why the repeats were important. 5 (e) Use the graph to find the concentration of sodium choride soution that has the same water potentia as the potato cyinders....mo dm -3 8 Turn over (11)

12 12 6 Read the passage beow. Most cases of cervica cancer are caused by infection with Human Papioma Virus (HPV). This virus can be spread by sexua contact. There are many types of HPV, each identified by a number. Most of these types are harmess but types 16 and 18 are most ikey to cause cervica cancer. A vaccine made from HPV types 16 and 18 is offered to girs aged 12 to 13. Three injections of the vaccine are given over six months. In cinica trias, the vaccine has proved very effective in protecting against HPV types 16 and 18. However, it wi be many years before it can be shown that this vaccination programme has reduced cases of cervica cancer. Unti then, smear tests wi continue to be offered to women, even if they have been vaccinated. A smear test aows abnorma ces in the cervix to be identified so that they can be removed before cervica cancer deveops. The Department of Heath has estimated that 80% of girs aged 12 to 13 need to be vaccinated to achieve herd immunity to HPV types 16 and 18. Herd immunity is where enough peope have been vaccinated to reduce significanty the spread of HPV through the popuation Use information from this passage and your own knowedge to answer the foowing questions. 6 (a) HPV vaccine is offered to girs aged 12 to 13 (ine 5). Suggest why it is offered to this age group. 6 (b) The vaccine is made from HPV types 16 and 18 (ine 5). Expain why this vaccine may not protect against other types of this virus. (12)

13 13 6 (c) Three injections of the vaccine are given (ines 5 to 6). Use your knowedge of immunity to suggest why. 6 (d) It wi be many years before it can be shown that this vaccination programme has reduced cases of cervica cancer (ines 7 to 9). Suggest two reasons why (e) Smear tests wi continue to be offered to women, even if they have been vaccinated (ines 9 to 10). Suggest why women who have been vaccinated sti need to be offered smear tests. 6 (f) Suggest one reason why vaccinating a arge number of peope woud reduce significanty the spread of HPV through the popuation (ines 14 to 16). 10 Turn over (13)

14 14 7 (a) Pumonary tubercuosis is a disease of the ungs. Describe the transmission and course of infection of pumonary tubercuosis. (5 marks) (Extra space)... (14)

15 15 7 (b) Emphysema is another disease of the ungs. Peope with emphysema may fee weak and tired. Expain why. (5 marks) (Extra space) END OF QUESTIONS (15)

16 16 There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Copyright 2011 AQA and its icensors. A rights reserved. (16)