convert information to impulse allow send impulse to sensory neurones / brain

Transcription

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2 Mark schemes detect changes in surroundings or detect stimuli allow any named stimulus for skin convert information to impulse allow send impulse to sensory neurones / brain (i) muscle contract(ion) gland release / secrete / produce chemical / hormone / enzyme mark for each effector mark for each response response must match type of effector (if given) ignore examples ignore relax(ation) / movement for contraction do not allow expansion for muscles 4 any one from: (maintain temperature at which) enzymes work best so chemical reactions are fast(est) prevent damage to cells / enzymes allow prevent enzymes being denatured (by temperature being too high) [7] 2 (76 28) 2 96 (units / h) allow 96 (units / h) with no working shown for 2 marks allow.6 units / min for mark allow answer in range of (units / h) for mark increased blood glucose concentration causes insulin release from pancreas which stimulates cells to absorb glucose / sugar from the blood, so blood glucose concentration decreases Page 2 of 8

3 (c) any three from: at least one advantage and one disadvantage of the system(s) must be given for full marks allow responses phrased in terms of the meter and injection systems advantages of the new system: better control so reduces risk of future health problems allow fewer low / high blood glucose periods so safer no need to estimate dose of insulin less chance of giving too much / little insulin system works automatically / continuously so no need to test / inject disadvantages of the new system: (d) system is always attached so may restrict activities allow pump is difficult to hide pump has to be carried somewhere allow risk of discomfort pump will need re-filling risk of infection or risk of tissue damage (at injection site) line might come out accept new system more expensive qualified conclusion: a statement as to which system is better with reference to at least one advantage and one disadvantage for example, the new system is better because although it is more expensive, it works automatically blood glucose concentration goes too low blood glucose concentration detected by pancreas pancreas releases glucagon (glucagon causes) cells to convert to glycogen into glucose 3 glucose released into blood [3] Page 3 of 8

4 3 (c) in the blood(stream) allow plasma ignore dissolved or in solution all three plots correct accept two correct plots for mark suitable line drawn hour 2 (d) = 45 identification of steepest part of graph and correct readings taken (e) line on graph showing extrapolation for person B correct value read from graph (at 30 mg per 00 cm 3 ) allow mark for a value of hours if no extrapolation shown 2 [9] 4 (i) A pituitary allow hypothalamus B ovary / ovaries in blood (stream) accept in plasma ignore dissolved (i) FSH and Luteinising Hormone (LH) fertilised OR reference to sperm form embryos / ball of cells or cell division (embryo) inserted into mother s womb / uterus allow (fertilised egg) is inserted into mother s womb / uterus Page 4 of 8

5 (iii) any one from: multiple births lead to low birth weight multiple births cause possible harm to mother / fetus / embryo / baby / miscarriages allow premature ignore reference to cost / ethics / population (c) (i) any one from: almost identical allow S (slightly) more successful both approximately 20% larger numbers (in clinic R) (in 2007) allow only 98 (in S) (compared to 004 (in R)) results likely to be more repeatable (in 2008) allow more reliable do not accept more reproducible / accurate / precise [] 5 pancreas allow phonetic spelling (i) A shortest / quicker time (to work) D acts for longest time mark dependent on D allow D will last until / breakfast / 24 hours (iii) diet / exercise if diet is qualified, then will need correct qualification, e.g. less carbohydrate / sugar accept pancreas transplant / stem cell treatment [6] Page 5 of 8

6 6 insulin extra ring drawn cancels the mark pancreas extra ring drawn cancels the mark (c) diabetes extra ring drawn cancels the mark [3] 7 pituitary (gland / body) oestrogen inhibits the release of FSH ignore references to LH FSH stimulates follicle development / causes egg to develop or no follicle / egg development if high oestrogen accept growth / maturing / ripening for development no ovulation / no egg release do not accept no egg to be fertilised [4] 8 inhibits FSH (production / secretion) (therefore) no eggs mature / released if no other marks gained allow mark for no eggs produced or effect of FSH on ovary described references to LH are neutral Page 6 of 8

7 maximum 4 marks if no conclusion Pros max 2marks from 4 marks e.g. large scale trial gave better results chose uneducated women so that if these women could use it correctly, women elsewhere would be able to cons max 3 marks from 4 marks e.g. used pill with high dose of hormone either so results not valid for general use of hormone or dangerous side effects ignored women not told pill was experimental / pill might have side effects no placebo should have tried a range of doses should have done pre-trial to check for side effects 4 conclusion mark e.g. trials flawed therefore cons outweigh pros accept reverse e.g. trials flawed but pros outweigh cons [7] 9 (i) any one from: chemical messenger / message allow substance / material which is a messenger chemical / substance produced by a gland allow material produced by a gland chemical / substance transported to / acting on a target organ chemical / substance that controls body functions gland / named endocrine gland brain alone is insufficient allow phonetic spelling Page 7 of 8

8 (iii) in blood / plasma or circulatory system or bloodstream accept blood vessels / named do not accept blood cells / named each hormone must be linked to correct action apply list principle ignore the gland producing hormone FSH stimulates oestrogen (production) / egg maturation / egg ripening oestrogen inhibits FSH ignore production / development of egg allow oestrogen stimulates LH / build up of uterine lining LH stimulates egg / ovum release / ovulation accept LH inhibits oestrogen accept LH controls / stimulates growth of corpus luteum ignore production of egg [6] Page 8 of 8