Movement of Substances in and out of Cells Mark Scheme Level Subject Exam Board Unit Topic Difficulty Level Booklet GCSE Biology AQA B3 Movement of Substances in and out of cells Bronze Level Mark Scheme Time Allowed: 8 minutes Score: /8 Percentage: /00 Page
M.(a) (i) alveoli / alveolus allow air sacs allow phonetic spelling any one from: protection (of lungs / heart) help you breathe / inflate lungs. (i) diffusion capillaries (iii) any two from: (have many) alveoli allow air sacs large surface / area thin (exchange) surface or short diffusion pathway accept only one / two cell(s) thick good blood supply / many capillaries allow (kept) ventilated or maintained concentration gradient. [6] M.(a) (i) water / H O accept oxygen allow H O do not allow H O or HO (iii) the mineral ions are absorbed by active transport the absorption of mineral ions needs energy have (many root) hairs (which) give a large surface area (for absorption) Page
carbon dioxide in or oxygen out or control water loss accept gas exchange ignore gases in and out ignore gain / lose water (c) (i) guard cells (stomata are) closed allow there is no gap / space (iii) plant will wilt / droop ignore die [9] M3.(a) osmosis partially permeable (i) any two from: allow correct answers in terms of A vacuole is small(er) cytoplasm has shrunk allow cytoplasm is smaller gap between cytoplasm and cell wall cell wall curves inwards allow cell B is flaccid or cell A is turgid the (cell) membrane has moved away from the wall Page 3
any one from: water will move / diffuse in (cells) will swell (cells) will burst ignore turgid (c) villi give the small intestines a large surface area villi have many blood capillaries [7] M4.(a) (i) (37C is the same as human) body temperature any one from: urea glucose sodium ignore water (iii) (as they are) small enough to pass through (the membrane) allow because there is a high concentration in the fake blood and a low concentration in the water (so will diffuse across) (iv) glucose any two from: Page 4
don t have to go to hospital or done at home rather than hospital less effect on lifestyle / can be mobile always filtering urea out continuous is insufficient don t need a medical professional (to do it for you) allow takes a shorter time allow does not have to be connected to blood vessels ignore less painful [6] M5.(a) (i) diffusion apply list principle A apply list principle (i) osmosis apply list principle R apply list principle [4] M6.(a) (i) capillary diffusion Page 5
(i) Z ignore any names large / increased surface / area allow all food absorbed or to absorb more food or improved diffusion [4] M7. (a) (i) capillary diffusion (iii) Carbon dioxide low(er) high(er) Oxygen high(er) low(er) mark for each correct row (i) red blood cells haemoglobin Page 6
[6] M8. (a) transpiration (i) 00 correct answer with or without working if answer incorrect: allow mark for 8 5 or allow mark for answer from candidate s count 5 R allow P or Q if candidate s answer to (i) nearer to value for one of those do not allow R if the answer to (i) would give an answer of P or Q allow R if (i) is blank (iii) few stomat allow no stomata on upper surface / all stomata on lower surface little / less transpiration or little / less water (vapour) loss / enable water to be retained allow no water loss from upper surface [6] Page 7
M9. (a) 4 correct = 4 marks 3 correct = 3 marks correct = marks correct = mark extra line from a structure cancels the mark 4 diffusion [5] M0. (a) transpiration increase then decrease maximum rate at 36-38 ( C ) / 540-560 (grams per day) any figure in these ranges Page 8
(c) (i) reduce water loss / prevent wilting allow stops water loss 40-45 C [5] M. (a) (i) diffusion A (i) osmosis R [4] M. (a) (i) capillary diffusion Page 9
(i) Z ignore any names large / increased surface / area / or to absorb more food or improved diffusion allow all food absorbed [4] M3. (a) (i) villus its outer surface is one cell thick cancel mark for each extra box ticked it has a large surface area it has good blood supply diffusion [5] Page 0
M4. (a) (i) root hair any two from: ignore food water ions / minerals / nutrients / salts / correct named eg nitrates ignore N,P,K oxygen (i) stomata diffusion [5] M5. (a) B Narrow(er) small(er) / thin(ner)(air) passages / bronchioles allow muscle fibres are contracted allow oxygen instead of air or less air can pass through ignore reference to surface area or harder for air to enter (c) (i) salbutamol causes relaxation / reduces contraction Page
widens / enlarges / bronchioles / (air) passages allow oxygen instead of air or allows air through more easily or allows person to breathe more easily [4] M6. (a) B C (c) D (d) (i) upwards / outwards flattened oxygen / carbon dioxide [6] Page
M7. (a) ions accept urea (i) D 0.9: accept 9:0 6: (iii) C allow ecf from (c) 78 dm 3 (d) Comp. with Man A The same Higher Lower urine concentration extra box ticked in any row cancels the mark for that row [8] Page 3
M8. (a) (i) 0 M water entered cells by osmosis because the concentration of water outside cells was higher than inside the cells 0.5 M because the chip did not change mass in this solution [5] M9. (a) (i) (D) greatest loss in mass in a given time (yes) leaves B and C both lost mass (i) stomata accept stoma there are no stomata on upper surface and most water is lost via stomata Page 4
so blocking the stomata on leaf B will reduce the water loss compared with leaf C [5] M0. (a) A = alveolus allow air sac / alveoli B = diaphragm ignore labelling of C and D A (c) (i) red blood cells plasma [5] M. (a) root hair (i) 85 if incorrect unit added = 0 0.85 ignore working or lack of working Page 5
accept correct answer from candidate s (i) for marks with no answer or wrong answer gains mark accept ecf (iii) absorb more water / ions allow get / collect / take in / take up / soak up / suck up for absorb allow lots for more allow moisture for water allow minerals / salts / nutrients for ions do not allow food or named foods absorb water / ions gains mark or large surface area to absorb water / ions () large surface area linked to incorrect function = ignore small so short diffusion pathway [6] M. (a) B = rib C = diaphragm (i) D allow lower case carbon dioxide [4] Page 6
M3. (a) (i) on diagram: arrow drawn from cell X, through air space and out through stoma above stoma transpiration (i) 3 5 ignore units any two from: warmest / hottest / brightest time of day accept warmer / hotter or sun higher in sky water evaporates fastest stomata open / more open [5] M4. (a) (i) increased / thick(er) allow more / wide(r) / broad decreased IGNORE working or lack of working correct figures from table. and. but no answer / wrong answer = mark [4] Page 7
M5. (a) (i) 0 osmosis 0.5 no change in mass / weight allow chip / it stays the same or no (net) osmosis / same amount of water in and out (c) repeat / use more chips in each solution allow use of other people s results do not allow get more results unqualified do not allow leave longer / use more concentrations / better instrumentation [5] M6. (a) (i) red cell diffusion Page 8
(iii) (iv) haemoglobin a nucleus (on diagram) arrow from any part of blood to air [5] M7. any two from: more or most ions / sodium / chloride or replaces ions / sodium / chloride do not accept more ions / sodium / chloride for energy lost in sweat to keep blood concentration constant less sugar therefore less chance of sugar rush [] M8. (a) correctly labelled on diagram (i) X on an alveolus centre of X on the alveolus wall or inside the alveolus not if the centre is outside arrow pointing downwards accept anywhere but must point down Page 9
in sequence trachea bronchi 3 bronchioles 4 alveoli (c) diffusion accept positive indicator [4] M9. (a) 94.8 (i) to cool (the body) / maintain (body) temperature do not accept let out heat (iii) water and ions water ignore CO, and vapour (c) any two from: used in respiration provides energy (energy) needed for movement / running / muscle action Page 0
[6] M30. (i) On diagram: oxygen arrow to blood from air and CO arrow to air from blood oxygen arrow to red blood cell CO arrow from plasma diffusion (iii) large surface or large area do not accept space [5] M3. in correct sequence: breathing diffusion respiration [3] Page
M3. Quality of written communication for ideas given in a sensible order; comparison made for geranium and cactus for each feature(ie not just list for geranium followed by list for cactus) + linking of feature & explanation any four features + explanations from: Feature cactus has: thicker cuticle smaller surface area fewer stomata stomata open at night / closed in day more widespread roots more water storage tissue accept converse points for geranium plant Explanation waterproof / keeps water in less water loss / less heat absorbed less water loss (closed when warmest) so less water loss quickly absorbs water (after rain) / access to bigger area for absorbing water / absorb more water little water available in environment / can survive drought / avoids dehydration 4 [5] Page
M33. (i) oxygen into the blood stream arrow must start inside alveolus and finish outside the capillary carbon dioxide out of the blood stream arrow must start inside the capillary and finish inside the alveolus (iii) carries/takes up/releases oxygen or carbon dioxide accept forms oxyhaemoglobin [3] M34. (a) falls from 0.5 to 0.9 but by 0.06 gains two marks if neither figure given, accept steadily / at constant rate for one mark accept mass of oxygen inversely related / negative correlation to height above sea level for marks (i).8 accept correct readings from graph for (5 and 6.8) if Page 3
subtraction incorrect for one mark allow one mark for correct subtraction from incorrect readings (blood can carry) more oxygen [6] M35. (a) (i) trachea accept windpipe (left) lung or lungs do not credit right lung carbon dioxide or water vapour do not credit just water oxygen answers in terms of used air or fresh air or of temperature differences are not acceptable [4] ## (a) oxygen passes from the air/lungs into the body gains mark but Page 4
oxygen passes from the air/lungs into the blood gains marks carbon dioxide passes from the body into the air/lungs gains mark but carbon dioxide passes from the blood into the air/lungs gains marks 4 increased/5% more gains mark but 6 times more (in air breathed out) gains marks [6] Page 5