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

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