1
1. (a) A right atrium ; [accept right auricle]
B (pulmonary) semilunar valve ;
C mitral / biscupid / (left) av, valve ; 3
(b) 1 Reference to, pacemaker / SA node / SAN ;
2 (Wave of) excitation / eq, in (walls) of atria ;
3 Causes contraction of (muscle in) atria (walls) ;
4 Delay
5 Conducted to
at, AV node / AVN ;
ventricles[7]
via, bundles of His / Purkyne fibres ; max 4
2. (a) narrowing of the arteries ; thrombosis / blood clot ; 2
(b) (i) age and gender ; 1
(ii) both increased with age ; figures similar 0-34 / over 65 ; deaths in males greater between 25-74 / converse for females / valid comparison for any age group in this range ; males levels off 45 onwards, females rises throughout ; 3
[6]
3. (a) A is, an artery / named artery, and B is, a vein / named vein ; 1
(b) (Lining / wall) one cell thick ; Thin cells / simple epithelium / squamous epithelium ; Alternative to first two
marking points – Thin walls ; Pores ; Selectively / partially permeable ; 2
(c) For transport / eq of, solutes / named solute / nutrients / molecules, to / from, cells / tissues ;
OR
Movement of waste products / named waste product from cells ; 1
(d) Increased blood pressure / hydrostatic pressure / hypertension / increased capillary permeability / decrease in plasma protein / colloidal osmotic pressure / protein / amino acid deficient diet / blocked lymphatic vessels / faulty valves in lymphatic vessels ; 1
[5]
2
4. (a) Arrow drawn between point where ventricular pressure curve starts to rise and where curve cuts 5 kPa line ; 1
(b) 60 ÷ 1.0 ; [accept equivalent calculations] = 60 beats per minute ; [accept range 60 to 64] 2
(c) Reference to closure of semilunar valve ; Elasticity / eq of aorta wall ; Recoil (in aorta) maintains pressure ; Reference to refilling / relaxation of ventricle ; 3
(d) Right ventricle pumps blood to lungs ; Left ventricle pumps blood all around the body ; Correct reference to relative
[9]
thickness of ventricular walls ; Correct reference to pressure in relation to lungs / body / e.g. more pressure needed to pump blood round body / converse OR less resistance to blood flow in lungs / converse ; 3
5. (a) 1. Rhythmic / sequence (of events) in each heart beat ;
2. {Initiated / controlled} by {pacemaker / SAN (sinoatrial node)} ;
3. Reference to atrial {systole / contraction} ;
4. Reference to ventricular {systole / contraction} ;
5. (complete) diastole / relaxation (of heart) ;
[points 3 to 5 must be in sequence] 3
(b) Coronary artery ;
From aorta ;
Supplies {blood / oxygen / glucose / nutrients / named nutrient} to heart {muscle / tissue / myocardium} / correct reference to removal of {waste products / named waste product} by coronary circulation ;
Returns to right atrium / coronary sinus / cardiac veins ; 3 [6]
6. (a) Right
B
atrium;
Left
ventricle; 2
(b) Lung; [however qualified] 1
(c) 1. Reference to {narrow / extremely long} capillaries;
3
2. Reference to blood in the lungs / reference to oxygenation of blood;
3. Results in {low pressure / loss of pressure} of blood (when it emerges from the lungs);
4. Not enough pressure to get through rest of {capillary network / the body};
5. Pumping the blood again {raises / restores} lost pressure OR provides extra boost of pressure / reference to
second pump;
6. Higher pressure in systemic circulation / lower
pressure in pulmonary circulation; 3
(d) (i) Dartery AND E vein; 1
(ii) Thick (muscular) {wall / layer} OR Rounded {shape / lumen} OR Smaller lumen; 1
[8]
7. (a) Cell membrane structure OR (steroid) hormone production OR Bile salt production OR Vitamin D production in the skin; 1
(b) 1. High (LDL) cholesterol in blood circulation;
2. Increases the likelihood of {deposits / plaques / atheroma} on arterial wall;
3. Narrows arteries / blocks arteries / restricts blood flow;
4. Hardens arteries / makes arteries less elastic;
5. Reference to atherosclerosis;
6. Increases risk of {CHD / blood clots / angina / heart attack / eq}; 4
(c) (i) Reduce intake of saturated fat / eat food with more plant sterols; 1
4
(ii) (Most) cholesterol produced by liver; Healthier margarine can only {affect dietary intake / reduce absorption from gut}; 2
[8]
8. (a) 3
Structural feature
Blood vessel Valves present Wall has pores Wall a single layer of cells
Capillary Vein
(b) (Elastic recoil) maintains pressure (in artery) (flexibility) to allow for {blood pressure / pulse}; 1
[4]
9. (a) [Points must be comparative] max 3
Arteries Veins
More (smooth) muscle / eq Less (smooth) muscle
More elastic {fibres / tissue} / elastin Less elastic {fibres / tissue}
No valves (except aorta and pulmonary artery) Valves present
Narrow lumen / eq Wider lumen
Thick layer of collagen (fibres) / eq Thin layer of collagen fibres
Thick wall Thin wall
(b) Higher (blood) pressure / more chance of damage to endothelium; 1
(c) High {hydrostatic / blood} pressure;
Which is higher than {solute potential gradient / eq} / correct osmotic effect described;
(Plasma forced out) through {pores / gaps} in capillary wall;
The fluid is forced out of the capillary into the intercellular space; 2
5
(d) (i) Blocked lymph vessels / high blood pressure / {low solute potential / high water potential} in blood / loss of plasma proteins / damage to tissue / histamine / eq; 1
(ii) Oedema; 1 [8]
10. [Only allow points if linked to aspect of diet]
1. High intake of {saturated fat / animal fat / example of fat / cholesterol};
2. Atherosclerosis / description of deposition inside arteries;
3. (Which leads to) reduced {blood flow / oxygen / eq) to heart muscle / increased blood pressure (in coronary circulation) / reference to thrombosis;
4. High {salt / Na+} intake;
5. High blood pressure / hypertension;
6. (Which leads to increased) {risk / eq} of {heart attack / heart failure / myocardial infarction}; 3
[3]
11. (a) Flatworm has a large surface area : volume ratio / converse; Diffusion {sufficient / effective} for flatworm’s {needs / eq} / converse; Mammal {has higher metabolic rate / is warm blooded / eq} / converse; 2
(b) (i) Top two open; Bottom two closed; 2
(ii) X drawn anywhere in the right atrium; 1
(iii) Pacemaker / sets rhythm of heart / initiates cardiac cycle / eq; 1
(c) Blood at high pressure; High concentration of oxygen / eq; High concentration of glucose / eq; 2
[8]
12. (a) Platelets; Prothrombin; Fibrinogen; 3
(b) 1. Lack of blood to {cardiac / heart} muscle;
2. So lack of {oxygen / glucose} / ischaemic / anaerobic / eq;
3. Muscle stops working / damaged / cells die;
4. Pain / angina / lactic acid build up;
5. Myocardial infarction / heart attack / eq; 3
6
(c) Warfarin / aspirin / streptokinase / adheparin / hirudin / clopidogrel; 1 [7]
13. (a) 1. Higher death (rate) among men than women in all countries;
2. Highest (rates) of death in Russia / lowest (rates) of death in France;
3. Any valid comparison between countries;
4. Supporting data quoted to back up any valid point;
5. Correct reference to different ratio of men / women death rates between countries; max 3
(b) There is no {difference / correlation} in the death rates between people who eat lots of fruit and vegetables and those who {don’t eat / eat less} fruit and vegetables / eq; 1
(c) [Paired points - marks for reasons must be linked to a potential difference] 4
Potential difference
1.
Reason
Different levels of health care; Better treatment / diagnosis / drug availability / eq;
2. Smoking; Smoking can cause atherosclerosis / carbon monoxide reduces oxygen transport / nicotine increase blood pressure / eq;
3. {Saturated fat / red meat / eq} intake / converse;
Raises blood cholesterol level / HDL : LDL ratio / eq;
4. Lack of exercise; Exercise strengthens heart / eq;
5. Obesity levels; Higher {fat / cholesterol} levels / eq;
6. Levels of stress; Adrenaline / high blood pressure / fast heart rate / eq;
7. Health awareness; Knowledge of risk factors aids preventative action / eq;
8. Poverty / poor living conditions; Affects {diet / health / eq};
9. Alcohol intake; High levels increase blood pressure / {low levels may reduce risk of CHD / red wine antioxidants};
10. Age profile of country; CHD increases with age;
11. Genetic differences; Genes may affect health of heart, e.g. hypercholesteraemia (gene / allele);
12. Salt intake; High blood pressure;
13. Any valid point; Any valid linked reason; [8]
7
14. (a) A {Aortic / semi lunar / SL} valve;
B Aorta / aortic arch;
C {Atrio-ventricutar / AV / bicuspid / mitral} valve; 2
(b) 1. {Valves / named valve / C} close;
2. (To) prevent backflow (of blood);
3. Reference to {contraction / systole} of ventricle;
4. Thick (muscular) wall / more muscle;
5. Provides high {pressure / force / eq};
6. To pump blood through {systemic circulation / round body / eq};
7. Reference to elasticity of {aorta / B} (to accommodate blood expelled from ventricle) / eq; 4
(c) (i) 1. Uterus bigger / more tissue;
2. More muscle development / eq;
3. Reference to {development / maintenance} of {placenta / eq};
4. Reference to development of {fetus / baby};
[Maximum three marks]
(ii) 1. {More / greater} contraction / heart works harder;
2. (Because) {blood / oxygen / nutrients};
3. (Pumped to) {uterus / placenta / fetus / mother’s body}; 4 [10]
15. (a) (i) 1. Reference to use of callipers;
2. Reference to needing to take several readings from several sites / two suitable named sites, e.g. {waist / triceps / back / upper arm / thigh hip};
3. Pinch {skin and fat only / no muscle};
4. Place jaws of skinfold callipers over the fold (close to the fingers);
5. Continue to hold the fold of skin and release the trigger of the calliper;
6. Read skinfold thickness from scale;
7. Reference to using [table / graph / chart} to determine body fat; 4
8
(ii) Raised {cholesterol / lipid / fatty acid / triglyceride} level in {plasma / blood};
Increased risk of {atheroma / formation of plaques / atherosclerosis} (in arteries);
Restricted blood flow / narrowing of lumen;
Raised blood pressure / hypertension / coronary heart disease; 2
(b) Increasing LDL levels increase {risk / eq} of CHD; Credit manipulation of figures / biggest increase between 120-141 and 142- 167 / eq; 2
[8]
16. (a) (i) COOH; 2
CO
H;;
(ii) Saturated;
No double bonds in (hydrocarbon) chain; 2
(b) (i) Anything that {affects / raises} the chance of harm / eq; 1
(ii) 1. Strain on the heart;
2. Raises blood pressure;
3. Raises cholesterol / LDL (in the blood);
4. Increased risk of formation of {atheroma / plaques};
5. Atherosclerosis / atherosclerosis explained / eq;
6. Increased risk of type 2 diabetes / explained; 3
(c) 1. Glucose is {a monosaccharide / soluble / doesn’t need to be digested} / eq;
2. Glucose can be quickly absorbed into the blood stream;
3. Can pass into muscle (cells);
4. Can be used for respiration;
5. To provide energy;
6. For (muscle) contraction; 3 [11]
17. (a) Ventricular systole; 1
(b) 1. Relaxation of atria and ventricles;
9
2. Reduces pressure (inside heart) / eq;
3. Refilling / eq;
4. AV valves are open;
(c) 1. Correct reference to the coronary circulation
2. Via the coronary artery;
;
3. From the aorta;
4. Reference to capillaries (within) cardiac muscles;
5. Reference to {red blood cells / haemoglobin} {carrying / releasing} oxygen; 3
[6]
18. (a) (i) Mortality falls as dietary fibre intake increases;
Almost linear relationship / negative correlation / inversely proportional;
Small increase in fibre has large effect;
Quantitative use of figures. 3
(ii) 1. Increases bulk of faeces;
2. Increases speed of {passage / peristalsis} (of faeces through the colon);
3. Carcinogens pass through the gut more quickly;
4. So less chance of their absorption;
5. Fibre absorbs carcinogens; 2
(b) 1. Weakening of gut musculature / eq (with age);
2. Increase in {pressure / eq} in colon;
3. Reference to {pouching / formation of pouches} (in the mucosa);
4. Lower dietary fibre (in diet of elderly);
5. (Because) eating {less food / more convenience food};
6. Poor diet when young; 3 [8]
19. (a) Increasing the number of risk factors increases risk of CHD;
Increase by one risk factor double incidence / eq;
Adding third risk factor has larger effect on incidence;
Relevant use of manipulated figures; 3
(b) High blood cholesterol:
1. Fatty deposition in artery walls / plaque formation;
10
2. Atheroma formed;
3. Increased blood pressure;
4. Lumen of (coronary) arteries narrowed / reduced elasticity of artery wall / eq;
5. Correct reference to LDLs;
High blood pressure:
6. Damage to (lining of) arteries;
7. Risk of aneurysm / damaged lining (of arteries) rupturing;
8. Increased risk of blood clot blocking coronary arteries;
9. Correct reference to inflammatory response;
Smoking:
10. Increases blood pressure;
11. Increases risk of aneurysm;
12. Less antioxidants / more free radicals;
13. Increases {number / activation} of platelets;
14. (Leading to) increased risk of blood clot blocking coronary arteries;
General points [allow in any section]:
15. Reduced blood supply to heart muscle;
16. Angina / increased risk of heart attack;
17. Reference to interactions between factors to increase risk;
18. Correct reference to atherosclerosis; 6
[Maximum 3 marks for each risk factor] [9]
20. (a) Artery / arteriole ; 1
(b) (i) Tunica media / middle coat ; 1
(ii) Provide {strength / support } / prevents bursting ; Idea that they enable artery to withstand high blood pressure / eq ; 2
11
(c) 1. Separation of deoxygenated and oxygenated blood ;
2. (Therefore) better {oxygenation of blood / oxygen supply to tissues} ;
3. Maintains different pressure to lungs and rest of body / eq ;
4. Mammals have a high (er) demand for oxygen ;
5. Idea of repressurisation ; 2 [6]
21. (a) (i) 0.14% / 0.07% per year; 1
(ii) 3.9 - 4 times; 1
(b) (i) The greater the BMI the greater the chance of dying due to coronary heart disease / eq;
Correct reference to figures; 2
(ii) BMI = metres)in (height
kg)(in mass body)(2
; 1
(iii) 1. Fatty deposits in arteries / atheroma / plaques / reference to atherosclerosis;
2. Higher cholesterol levels;
3. Higher blood pressure;
4. Risk of damage to (coronary) arteries;
5. Risk of blood clot blocking coronary
6. Risk of type II diabetes; 3
arteries;
[8]
22. (a) (i) Heart is visible / transparent organism / reference to ethical issues / eq; 1
(ii) 1. Temperature;
2. Volume of solution;
3. Daphnia {same age / growth conditions} / eq;
4. Time in solution prior to counting heart rate / eq; 2
12
(iii) 1. Very active / high metabolic rate;
2. Supplies oxygen / removes CO2;
3. Slow diffusion
4. Low SA/V ratio / eq; 2
(through body surface) / diffusion insufficient / eq;
(b) 1. Will increase blood pressure;
2. Risk of damage to arteries;
3. Increase risk of heart attack / stroke / aneurysm;
4. More chance of atherosclerosis / eq;
5. Vasoconstriction / eq; 2 [7]
23. p
thromboplastin
prothrombin
fibrinogen
fibrin
red blood cells
All six correct - 3 marks five or four correct - 2 marks three or two correct - 1 mark one correct - 0 marks
[one mark for each two correct answers rounded down] [3]
24. (a) (i) {semilunar / aortic} valve 1
(ii) ventricular systole 1
(iii) A description and an explanation to include three from:
1. ventricles contract
2. atrioventricular(AV) valves dose
3. semilunar valves open /eq
4. due to higher pressure in ventricles;
5. compared to (atria / artery}
6. blood passes into {aorta / artery) 3
13
(b) (i) A suggestion to include three from:
1. reduced flow of blood to heart [ / cells]
2. lack of oxygen (to cells) / reference to anaerobic respiration / ischaemic / eq
3. cells / muscles damaged / die / eq
4. reference to lactic acid / angina 3
(ii) walls of the artery are elastic /eq 1
(c) An explanation to include:
1. angioplasty operation has less risk / eq
2. angioplasty is less invasive / less major operation / may not need general anaesthetic / faster recovery rate 2
(d) arteries carry blood under higher pressure / eq 1 [12]
25. (a) A description to include two from:
1. narrowing leads to higher blood pressure;
2. increases risk of {further damage to the artery wall
3. platelets stick to damaged wall;
/ aneurysm}
4. triggers blood clotting process / eq;
5. correct reference to mast / foam cells / inflammatory response;
(b) (i) A description to include three from:
1. platelets stick to damaged wall of artery / eq;
2. thromboplastin released (from damaged tissue/platelets);
3. correct reference to Ca2+ / Vit. K;
4. prothrombin converted to thrombin;
5. fibrinogen converted to fibrin;
6. fibrin mesh traps blood cells forming a clot; 3
14
(ii) An explanation to include two from:
1. blood clot blocks coronary
2. restricts blood flow to heart muscle;
artery;
3. lack of oxygen
4. for respiration / reference to anaerobic respiration;
to heart (muscle) / ischaemic;
5. insufficient energy release for contraction / infarction / damage to heart muscle; 3
[8]
26. (a) (i) reduce intake of fat / particularly saturated fat / correct examples / increase fibre / fresh fruit and vegetables / increase intake of foods containing sterols / stanols / include oily fish; 1
(ii) A suggestion and an explanation to include two from:
1. cholesterol synthesized by the body;
2. further detail e.g. made in liver / cholesterol made from saturated fats;
3. genetic factors;
4. further detail e.g. hypercholesterolaemia / number of LDL receptors;
(b) (i) 39.9 / 40.0%;;
(if wrong, 14.8 – 8.9 OR 5.9 seen;) 2
(ii) (Statin) B; 1
(iii) ref to {validity / reliability /identification of anomalous results / allows for variation }; NOT accuracy / precision
to confirm the drug was having the effect / eq; 2 [8]
27. (a) {fatty deposits / plaques / cholesterol / atheroma / eq} {narrows / blocks} arteries; less blood flow {to cardiac muscle (cells/tissues) / through coronary artery
}; less oxygen; anaerobic respiration; build up of {lactic acid / lactate} (causes pain); 3
15
(b) (i) 1873, 1614, 1790 kJ; [all three required for (1) mark] 1
(ii) A; 1
(iii) A less saturated
[8]
fatty acids / FA; less {cholesterol/LDLs} (made by liver); less / no cholesterol in diet; less chance of atherosclerosis/eq / {atheroma / fats} building up / depositing / being laid down on arteries; 3
28. (i) arrows moving from direction of veins through the atria towards ventricles on both sides; 1
(ii) sinoatrial node / SAN / pacemaker; 1 [2]
29. (a)
Statement about Daphnia Tick or cross
(i) The movement of fluid through the heart is an example of mass transport ;
(ii) Daphnia uses diffusion to transport oxygen into muscle cells ;
(iii) Daphnia tends to lose water from its body to the freshwater by osmosis ;
(iv) Daphnia can use active transport to move ions from the freshwater into its body ;
4
(b) (i) A = 50, B = 75 & C = 100; 1
(ii) 200; 1
16
(iii) 1. only three Daphnia used / not enough {samples / repeats} to be representative / only one Daphnia used per concentration;
2. different Daphnia used (for each caffeine concentration) / different Daphnia used for 35 au;
3. range not large enough to make prediction / eq;
4. Daphnia may respond differently at higher concentrations / eq OR they may die;
5. taking readings for 10 seconds not sufficient;
6. describe one environmental variable to be controlled / allow time for Daphnia to acclimatise;
7. need for a control; max 3 [9]
30. (a) (i) X = aorta/ aortic arch;
Y = (left) ventricle / cardiac
Z =
muscle;
coronary
artery /eq; 3
(ii) second box down on the left; 1
(iii) SAN / sino atrial node / pacemaker / eq; 1
(b) (i) 1. sequence of events from one beat to the next beat / eq;
2. reference to {contraction / systole} and {relaxation / diastole};
3. correct detail of sequence e.g. atrial systole → ventricular systole → diastole / approx 30% of time spent in systole and 70% in diastole;
4. correct detail of electrical regulation of cardiac cycle/eq; max 2
(ii) 1. left ventricle has {more / thicker} muscle / eq;
2. blood from (left ventricle) has to divide between more capillaries / eq;
3. left ventricle has to pump blood further / eq; max 2
17
(iii) 1. pressure increases as blood forced into ventricle during atrial systole;
2. pressure increases during (initial) ventricular systole/eq;
3. (due to) reducing volume of ventricle (causing pressure increase);
4. pressure starts to decrease due to blood into artery / loss of blood from ventricle;
5. decreases during diastole / eq;
6. (due to) increasing volume (of chamber); max 2
(c) 1. gender
2. smoking
3. genes / inheritance / eq
4. stress
5. high LDL level / LDL to HDL ratio / high blood cholesterol
6. reference to inappropriate diet such as high {salt / fat / cholesterol / calorie} intake / eq
7. high alcohol intake
8. obesity
9. lack of exercise / eq
Notes: two correct answers needed for one mark max 1
[12]
31. (a) 1. capillaries {have thin walls / made of flattened epithelium / thin cells / eq};
2. reference to presence of pores;
3. reference to basement membrane;
4. reference to permeability of capillary wall /eq; max 3
(b) 1. proteins are large (molecules);
2. cannot pass through capillary wall / eq; 2
(c) 1. idea of reduced concentration of plasma proteins / eq;
2. therefore reduced osmotic effect / eq; 2 [7]
18
32. (a) (i) artery; 1
(ii) Any two from the following pairs
1. thick {wall / layer} of (smooth) muscle / thick elastic {layer / wall};
:
2. allows artery to expand / withstand pressure from the pulse of blood / eq;
3. collagen (fibres); 4. provides strength / eq;
5. smooth lining; 6. prevent resistance to blood flow / eq;
7. small lumen / eq; 8. to maintain high pressure / eq; max 4
(b) 1. inhibits the enzyme (that catalyses the conversion);
2. by active site-directed inhibition / eq;
3. inhibitor {is a similar shape to the substrate } / blocks active site;
4. by non active site-directed inhibition;
5. inhibitor attaches to enzyme at point other than active site / eq;
6. (and) causes active site to change shape; max 4 [9]
33. (a) right-hand 1st box down; 1
(b) 1. (skeletal) muscle contracts / eq;
2. squeezes vein / named vein;
3. blood forced in both directions (away from squeezed area) / eq;
4. (one way) valves present (in veins);
5. one way flow / prevent backflow / eq;
6. reference to role of thorax e.g. pressure changes during inspiration / expiration / breathing;
7. lower pressure in {heart / atria} during {diastole / eq}; max 3
19
(c) 1. {squamous / pavement / flattened /thin / eq } cell / endothelium;
2. (only) one cell thick;
3. small lumen present /(capillary) small diameter;
4. pores present / gaps present / eq; max 2 [6]
34. (a) Drink Time taken for
180 heart beats / seconds
Caffeine concentration / mg
per 100ml
Instant coffee 33 to 34;
Filter coffee 58 to 60;
Tea 30;
3
(b) no {difference / effect} due to :
1. genotype / eq;
2. age;
3. size / eq;
4. gender /eq;
5. physiological state / eq;
6. pre-treatment / eq;
7. absorption rate /eq; max 3
(c) 1. variation due to chance / eq;
2. still some caffeine present within the organism / still some caffeine present on the surface;
3. idea of time to recover from effect of caffeine;
4. inaccuracy of measurements / eq; max 2 [8]
20
35. large surface area ; increases diffusion ; thin (wall) / single cell ; reduces diffusion distance ; reference to surfactant ; stops adhesion / eq ; reference to capillaries ; maintains, diffusion / concentration gradient ; 2 + 2
[4]
36. Bronchioles / alveolar ducts ;
Single / thin / squamous / flattened / type I pneumocyte ;
Increases / eq ;
Blood / capillaries / red blood cells ; 4 [4]
37. (a) 1. Thin / squamous / flattened (cells);
2. Decreases diffusion distance;
3. Large surface area (of cells);
4. Increases diffusion;
5. Of {respiratory gases / oxygen / carbon dioxide}; 3
(b) Increased {heart rate / diameter of lung (blood) vessels} OR increased {cardiac output / stroke volume}; 1
[4]
38. (a) 4
Process Requires energy from respiration (ATP)
Requires a concentration gradient
Diffusion 7 3
Facilitated diffusion 7 3
Osmosis 7 3
Active transport 3 7
[Two correct for one mark]
21
(b) 1. Large surface area; due to –
2. Many alveoli / eq;
3. Large number / networks of capillaries / eq;
4. Small diffusion path / thin exchange surface / eq;
5. {Flattened / thin / squamous} alveolar (epithelial) cells / walls;
6. Capillary (endothelial) cells / walls;
7. Large difference in concentration; due to –
8. Ventilating the lungs / eq;
9. Circulation of blood / eq; 4 [8]
39. Alveoli:
1. (Thin wall) of {squamous / flattened} epithelium;
2. Decreases diffusion distance;
3. Reference to blood flow in the capillaries;
4. Reference to ventilation / eq;
5. {Maintains / eq} {concentration / diffusion} {gradient / difference} of {(respiratory) gases / carbon dioxide / oxygen}; [Maximum 4 marks for Alveoli marking points (1 - 5)]
Placenta:
1. Reference to thin barrier between placenta and endometrium / eq / accept reference to chorionic villi;
2. Reference to counter-current flow;
3. Concentration gradient {maintained by / eq} blood flow;
4. Reference to fetal haemoglobin taking up oxygen; [5]
40. (a) Structure Letter on diagram
Y
X
Z
[all correct = 2 marks, one or two correct = 1 mark] 2
22
(b) 1. Walls of alveoli one cell thick / thin (epithelium);
2. Walls of {blood capillaries / endothelium} {one cell thick / thin};
3. Alveoli covered with a dense network of capillaries / eq;
4. Concentration gradients maintained by (blood flow / ventilation mechanism);
5. Large surface area provided by alveoli;
6. Oxygen combines rapidly with haemoglobin;
7. Correct reference to diffusion; 4 [6]
41. (a) 1. Oxygen (from alveoli) to capillary and carbon dioxide (from capillary) to alveoli;
2. By diffusion / movement of molecules from area of high concentration to an area of low concentration / eq; 2
(b) 1. Large surface area / lots of alveoli;
2. Large surface area of capillaries
3. Thin alveoli walls;
/ eq;
4. Thin capillary walls;
5. {Circulation of blood / ventilation of lungs} to maintain concentration difference;
6. Short diffusion pathway; 3
(c) (i) 1. CFTR (protein channel) does not work / eq;
2. Lack of Cl– ions transported into mucus / eq;
3. Water does not move into mucus by osmosis
/ eq; 2
(ii) 1. Mucus blocks airways/bronchioles/alveoli / eq;
2. Reduces surface area for gas exchange / diffusion;
3. Less oxygen (diffuses) into blood
4. Long diffusion pathway; 2
/ eq;
[9]
23
42. 1. (alveoli) have a thin wall / squamous epithelium / eq;
2. (and) have a large surface area;
3. ref. to increased diffusion / decreased diffusion distance / eq;
4. ref. to presence of surfactant;
5. function of surfactant;
6. ref. to capillaries;
7. {transport of (respiratory) gases / movement of blood} maintains diffusion gradient; 5
[5]
43. (a) Award up to three marks for the following in context
1. (thin wall) of {squamous/flattened} (epithelial cells);
2. small diffusion distance;
3. ref to blood flow in capillaries;
4. ref to ventilation;
5. maintains {concentration/diffusion} gradient of {gases/carbon dioxide/oxygen}; Max 3
(b) Award up to two marks for the following in context
1. mucus builds up in airways;
2. cilia cannot move it because it is thick/eq;
3. reducing ventilation (below blockage);
4. gas exchange occurs over {fewer alveoli / smaller surface area}; Max 2
(c) (i) Priya 1
(ii) Zac / Samir 1
(iii) 0.25;
Accept ¼, 1 in 4, 25%
Reject 1:3, 1 to 3 1
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(d) Award one mark for identifying a potential benefit and a further mark for an explanation of the benefit.
For example
1. to determine whether or not a parent is a carrier;
2. therefore can make informed decision about having children;
or
3. determine whether or not embryo has disease;
4. informed decisions can be made about {future care for child / termination of pregnancy} / treatment could start immediately;
Award one mark for identifying a potential disadvantage and a further mark for an explanation of the disadvantage.
For example
5. ref to false positives / negatives;
6. decisions on whether to terminate a pregnancy or not are based on wrong information;
or
7. other abnormalities may be found;
8. some social implication e.g. life insurance, finding {partner / job}, depression; 4
[12]
44. (a) far right-hand box; 1
(b) (i) 110 / first one / higher one / eq; 1
(ii) 1. high
2.
salt {intake / in diet / eq};
high
3.
(saturated) {fat / cholesterol / LDL / eq} {intake / in diet / eq};
high
4. smoking;
alcohol intake;
5. stress;
6. hardening of arteries / atherosclerosis / eq;
7. old age;
8. inherited trait / eq;
9. obesity / overweight;
10. lack of exercise / eq; max 2
(c) (i) 100%; 1
25
(ii) {twice as / ×2 more / 100% more} likely to have heart disease / eq; 1 [6]
45. (a) Award one mark for each of the following points in context to a maximum of three
1. {during first 5 years / initially} there is little change in death rates;
2. from late 70’s/early 80’s in most countries there is a lowering of death rates;
3. Poland is an exception when death rates have increased;
4. any quantitative manipulation of data e.g. death rate in Finland has halved over period; Max 3
(b) (i) Award one mark for each of the following points in context to a maximum of two.
1. Finland has high rates of CHD and high B.P.;
2. UK has high rates of CHD and high B.P.; Max 2
(ii) Award one mark for each of the following points in context to a maximum of two.
1. there is conflicting evidence;
2. Italy has high b.p. but low death rates; Max 2
(c) Award one mark for each of the following points in context to a maximum of three.
1. damage to artery walls;
2. ref. to blood clot;
3. blood clot can block arteries;
4. ref. to coronary arteries;
5. lack of (oxygenated) blood flow to heart muscle; Max 3 [10]
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46. (a) W = coronary arteries
X = aorta
Y = (left) pulmonary artery
Z = pulmonary vein
4 correct = 2 marks 2 or 3 correct = 1 mark 0 or 1 correct = 0 marks 2
(b) Award one mark for each of the following points in context to a maximum of four.
1. ventricle (muscle) contracts;
2. higher pressure in ventricles relative to atria;
3. (pressure) closes atrioventricular valve;
4. higher pressure in ventricles relative to the {aorta / pulmonary artery / arteries};
5. (pressure) opens the semilunar valve;
6. blood forced into the {aorta / pulmonary artery / arteries}; Max 4
(c) Award one mark for each of the following points in context to a maximum of three.
1. place Daphnia on {cavity slide / eq} with caffeine;
2. (focus on heart) using microscope;
3. ref. to range of caffeine concentrations;
4. ref. to repeats;
5. ref. to {water as control / zero caffeine concentration}; Max 3
Award one mark for each of the following points in context to a maximum of three.
1. control temperature;
2. reference to similar organisms used;
3. accurate measurement of DV;
4. reference to pretreatment; Max 3 [12]
47. (a) P aorta Accept pulmonary artery 1
Q vena cava Accept any named vein 1 R capillary 1
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(b) Correct answer (with or without working) = 2 marks Answer: 76(.2)%;
Correct working with incorrect answer = 1 mark 10.5 – 2.5 or 8 seen; 2
(c) (i) (pulses) due to {elastic recoil/eq} / general drop due to {friction / dividing into more vessels}; 1
(ii) (pressure drop) due to large volume of capillary network / friction between blood cells and walls of capillary; 1
[7]