OCR A old spec Flashcards

Question 1

Q

why large animals need large SA V

Answer

A

large / active, organisms have high(er), demand for oxygen / need to remove CO2 ; small(er), surface area to volume ratio / SA:V / surface area:volume ; surface area too small / distance too large / diffusion takes too long (to supply needs) ;

Question 2

Q

describe and explain adaptations of the gas exchange susteems

Answer

A

epithelium short (diffusion) distance ;

capillaries

delivers carbon dioxide (to be removed from blood) / carries oxygen away (from alveoli) ; short (diffusion) distance ;
diaphragm / intercostal muscles
ventilation / supply of oxygen (to alveoli) / removal of carbon dioxide (from alveoli) ;

mny alveoli to increase SA across which O2 AND CO2 diffuse

Question 3

Q

inspiration

Answer

A

diaphragm (contracts / flattens and) moves downwards ; intercostal muscles contract to move ribs, up / out ; increase volume of thorax ; reduce pressure inside thorax ; to below atmospheric pressure/creates pressure gradient / AW ;

Question 4

Q

single circulatory system:

Answer

A

blood passes through the heart once for each, circulation / circuit / cycle, of the body

Question 5

Q

closed circulatory system:

Answer

A

the blood is maintained inside vessels ;

Question 6

Q

source

Answer

A

site where, sucrose / sugars / assimilates, loaded (into phloem) / AW ;

Question 7

Q

sink

Answer

A

site where, sucrose / sugars / assimilates, unloaded / removed (from phloem) / AW ;
2

Question 8

Q

when park removed from tree, phloem removed oo, if a omplete ring of bark removed, th e tree swells abouve the cut. why

Answer

A

sugars) cannot pass the cut / AW ;
decrease water potential ; water moves into cells ;
(damage triggers) increased cell division ; to produce cells to store sugars ; cut causes, gall / infection ;

Question 9

Q

(A / goblet cells)

Answer

A

release mucus / AW ;

(mucus) traps, dust / particles / named particle ;

Question 10

Q

ciliated cell

Answer

A

/ B / cilia, wave / waft / move, mucus ;

to, top of trachea / back of mouth / AW ;

Question 11

Q

fuction of smooth muscle int eh bronchsu

Answer

A

to constrict the bronchus / AW ;

Question 12

Q

why capp and alveoli close

Answer

A

short, distance / path / AW ;

(so that) diffusion / concentration, gradient is, high / steep ; high rate of, (gas) exchange / diffusion ;

Question 13

Q

why alvreoli wall has elastic fibres

Answer

A

recoil / expel air / prevent bursting ;

Question 14

Q

why water loss by transpiration unavaoidable

Answer

A

stomata (open to) allow, gaseous exchange / carbon dioxide in / oxygen out / AW ;

(gaseous exchange) for photosynthesis ; (photosynthesis) essential for plant to, gain energy / make sugars ; some water lost through cuticle ;

Question 15

Q

xerohystes

Answer

A

reduce water (vapour) potential gradient / diffusion gradient ;
[A 1] hairy leaves ; trap water vapour / moisture ;
[A 2] stomata, in pits / sunken ; pits trap, water vapour / moisture ;
[A 3] rolled leaves / presence of hinge cells ; reduce surface area OR (rolled leaves) trap water vapour / moisture ;
[A 4] high solute concentration in cells ; reduces water potential inside leaf cells ;
[A 5] thick(er) cuticle ; (which is) waterproof / (relatively) impermeable ;
[A 6] small leaves / needles ; smaller surface area ; [A 7] fewer stomata ; reduces diffusion (of water vapour) ;
[A 8] stomata close, during the day ; reduces diffusion (of water vapour) ;
[A 9] most stomata on lower surface ; less exposure to sun OR cooler OR reduces diffusion (of water vapour) ;

Question 16

Q

why xylem lignified

Answer

A

Functions: F1 (lignin), strengthens / thickens, the (xylem) wall ;

F2 waterproofing (wall) / AW ;

F3 (improving) adhesion of water (molecules) ; F4 (spiral) pattern allows flexibility / stretching / movement; 2 max

ACCEPT support only if in specific context of supporting the xylem wall ACCEPT waterproofs cell

DO NOT ACCEPT adhesion and cohesion when used together Flexibility / stretching must ref, pattern of lignin laid down i.e. spirals
Explanation: E1 prevents collapse of xylem ; E2 (water) under tension / at low pressure / negative pressure; E3 reduces (lateral) loss of water, through wall ; E4 increases capillarity / AW ; E5 prevents stem breaking / AW ; in

Question 17

Q

fuction of the pits in the xylem

Answer

A

(pits) allow water to move, in / out / between, vessel(s) ; to bypass blockage ; supply water to other, tissues / (other types) cells / parts of plant ;

Question 18

Q

tissue found in the lungs

Answer

A

squamous epithialial

Question 19

Q

organ

Answer

A

(organ is) a collection of tissues / named tissues ; (working together) to carry a out a particular function

Question 20

Q

function of glycoprotein

Answer

A

1 (acting as) antigens ; 2 identification / recognition, (of cells) as, self / non-self / AW ; 3 cell signalling / described ; 4 receptor / binding site, for, hormone / (chemical) signal / (medicinal / named) drugs ;

5 ref. to receptor / binding site / trigger, on transport proteins / AW ; 6 cell adhesion / to hold cells together (in a tissue) ; 7 attach to water molecules (to stabilise membrane / cell)

Question 21

Q

ways that artery wall is diff to vein wall

Answer

A

Arteries have:

no valves ; endothelium / tunica intima, folded / AW ; more / thicker, muscle / elastic tissue / tunica media ; more / thicker, collagen / tunica externa ;

Question 22

Q

how hydrostatic pressure generated in the heart and why it falls as blodd moves from heart

Answer

A

contraction of ventricle, wall / muscle ;

more, (smaller) vessels / named vessels ;

(vessels) have larger, total lumen / cross sectional area ;

reduced resistance to blood flow ;

arteries, stretch / expand ;
loss of, fluid / plasma, from capillaries ;
2

Question 23

Q

why, when measuring vital capacity with the spirometer, us a nose clip

Answer

A

to ensure all air breathed comes from chamber OR to prevent, escape of air / entry of air, through nose ;

ACCEPT air may be breathed in or out through nose ACCEPT ensures breathes through mouth
make results invalid

Question 24

Q

why, when measuring vital capacity with the spirometer, us a nose clip

Answer

A

to ensure all air breathed comes from chamber OR to prevent, escape of air / entry of air, through nose ;

ACCEPT air may be breathed in or out through nose ACCEPT ensures breathes through mouth
make results invalid

Question 25

Q

procustions to take when using a spirometer

Answer

A

use (medical grade) oxygen / fresh air ;
Note question relates to measuring vital capacity ACCEPT ensure there is enough oxygen / air
disinfect mouthpiece ; ACCEPT change / wash mouthpiece
ref. to health of subject ; e.g. asthmatics
ref to correct functioning of equipment ;

Question 26

Q

why single cell nah need specialised exchange

Answer

A

large surface area to volume ratio ;

small so demand for, O2 / CO2, is low ;

idea of: diffusion (alone) is adequate to meet needs ;

Question 27

Q

fetal o2 diss curve

Answer

A

1 fetal haemoglobin has a higher affinity (for oxygen) ( than adult haemoglobin) ;

2 (fetal Hb) takes up oxygen in low(er) partial pressure of oxygen ;

3 placenta has low partial pressure of oxygen ;

4 at low partial pressure of oxygen / in placenta, adult (oxy)haemoglobin will dissociate / AW ;

Question 28

Q

benefits of bohr shift to actively respiring cells

Answer

A

1 (actively respiring tissue) needs / requires, more oxygen ;

2 for aerobic respiration / to release more energy ;

3 (actively respiring tissue produces) more CO2 ;

4 haemoglobin involved in transport of CO2 ;

5 less haemoglobin available to combine with O2 ;

6 (Bohr shift) causes more oxygen to be released

Question 29

Q

how water move from root to leaf

Answer

A

1 water moves into xylem down water potential gradient ;

2 root pressure / high (hydrostatic) pressure at bottom of xylem ;

3 water vapour loss / transpiration / evaporation, at leaves / top of plant ; 4 (creating) low (hydrostatic) pressure at top of xylem ;

5 water, under tension / pulled up (in a continuous column) ; 6 cohesion between water molecules / described ;

7 adhesion of water molecules to xylem / described ; 8 capillary action / described ;

9 water moves up (xylem / stem) by mass flow ; 10 from high(er) (hydrostatic) pressure to low(er) (hydrostatic) pressure / down (hydrostatic) pressure gradient ;

Question 30

Q

how histamine stimulates so=mooth muscle contraction

Answer

A

1 (histamine), binds / attaches, to, receptor / glycoprotein ;

idea of : 2 in / on, plasma / cell surface, membrane (of muscle cell) ;

3 complementary (shape) ;

4 triggers response / causes effect, inside cells ;

Question 31

Q

action of histamine and explain them

Answer

A

stimulates so=mooth muscle contraction
1 (histamine), binds / attaches, to, receptor / glycoprotein ;

idea of : 2 in / on, plasma / cell surface, membrane (of muscle cell) ;

3 complementary (shape) ;

4 triggers response / causes effect, inside cells ;

and makes capillary walls more permeable idea of : 1 more tissue fluid formed / increase in volume of tissue fluid ;

2 increase pressure in tissue ;

3 swelling / inflammation / oedema;

4 (more) white blood cells pass into tissues ;

5 larger molecules / (named) proteins , pass into tissue fluid

Question 32

Q

process of trainspiration

Answer

A

In the leaf: idea of : 1 water loss (from leaf) is replaced ;

2 via, apoplast / symplast / vacuolar, pathways ;

3 down water potential gradient / AW ;

4 (lost water replaced) by water from the xylem ;

In the xylem: 5 (loss of water) causes, low / negative, (hydrostatic) pressure (at top / in leaf) OR creates pressure gradient ;

idea of : 6 water moves, from higher pressure to lower pressure / down pressure gradient ;

7 under tension / pulled up / drawn up ;

8 by mass flow ;

9 cohesion / attraction, between water molecules ;

idea of : 10 column / stream / chain, of water (molecules) ;

Question 33

Q

transpiration

Answer

A

evaporation / loss of water vapour ;

from, aerial parts of plant / leaf / leaves ;

via stomata ;

Question 34

Q

why plants survive longer if ends of stem removed immediately before placed in water

Answer

A

Ref to : bubbles / air (present / being removed) ;

(blockage) in xylem ;

restore (continuous) column of water (in xylem) ;

Question 35

Q

explan how the diff cells and tissures make gas ex so effective

Answer

A

C1 thin / squamous, epithelium ; C2 thin endothelium (of capillary) ;

F1 (provides) short diffusion distance / described ;

F2 ref to surfactant (from epithelial cells) , reducing surface tension / preventing alveoli collapsing ;

C3 blood / red blood cells / erythrocytes ;

F3 transports (named) gas(es) , to / from , exchange surface / alveoli ; C4 diaphragm / intercostals , muscles ;

F4 (maintains / creates) diffusion / concentration , gradient ;

C5 ciliated epithelium / goblet cells / ciliated cells ; F5 idea of: protection from / removal of , dust / bacteria / pollen / spores ;

C6 cartilage ; F6 hold airway open ;

C7 smooth muscle
F7 constrict / control diameter of , airway / blood vessel ;

C8 elastic , fibres / tissue ; F8 for recoil / aiding ventilation ;

C9 macrophage / neutrophil ; F9 engulf / destroy pathogens or protect from infection ;

Question 36

Q

why left ventrivcle thicker

Answer

A

left ventricle

1 (more muscle to create) more force ;

2 (needs to create) higher pressure ;

3 push blood against greater , resistance / friction ;

4 (left ventricle) pumps blood further / pumps blood to all parts of body / supplies systemic circulation

Question 37

Q

how changes in pressure of the heart closes the AVV aka bicuspid valve

Answer

A

1 ventricular systole or ventricle , wall / muscle , contracts ;

2 (ventricular contraction) raises ventricular pressure ;

3 (ventricular pressure) higher than atrial pressure ;

4 idea of (pressure / movement of blood, generated by ventricular contraction) pushes valve shut ;

5 chordae tendinae prevent inversion ;

Question 38

Q

two adaptations of the sieve tube that enables massflow to occur

Answer

A

1 elongated elements ;

2 elements , joined end to end / form column ;

3 sieve plates / pores in end walls / perforated end plates / sieve pores ;

4 little cytoplasm / cytoplasm pushed to cell edges / thin (layer of) cytoplasm ;

5 no nucleus / few organelles ;

Question 39

Q

descried the process of phloem loading

Answer

A

1 active transport of, hydrogen ions / protons / H+ , out of companion cells ;

2 creates , hydrogen ion / concentration / diffusion , gradient ;

3 (facilitated) diffusion (of H+) back into companion cells ;

4 sucrose / assimilates , move in with hydrogen ions ;

5 by cotransport / through cotransport protein ;

6 sucrose / assimilates , (diffuse) through plasmodesmata (from companion cell to sieve element) ;

7 into sieve, tube / element ;

Question 40

Q

how steep con grad maintained in the lungs

Answer

A

EITHER D1 (continuous) blood flow (in the capillaries) ;

E1 to, bring in (more) carbon dioxide / take away (more) oxygen ;

OR

D2 oxygen combines with haemoglobin ; E2 to keep concentration in, blood / plasma, low ;

Question 41

Q

two advantages of keeping blood inside blood vessels

Answer

A

maintain / high(er), (blood) pressure ;

increase rate of, flow / delivery ; flow can be, diverted / directed / AW ;

Question 42

Q

how walls of artery enable it to withstand pressure and maintain pressure

Answer

A

to withstand pressure wall is thick ; (thick layer of) collagen ; (wall / collagen) provides strength ;

endothelium, corrugated / folded ;

idea of: no damage to, endothelium / artery (wall) (as it stretches) ;

max 3 to maintain pressure (thick layer of) elastic tissue / elastic fibres / elastin ; to cause recoil / return to original size ;

(thick layer of) smooth muscle ; narrows / constricts, lumen / artery ;

Question 43

Q

why water loss unavoidable during the day

Answer

A

1 2

3 4 5

6 7

stomata are open ; allow, gaseous exchange / entry of carbon dioxide / exit of oxygen ;

for photosynthesis ; water vapour leaves (the leaf) ; down a water (vapour) potential gradient ;

high(er) temperatures (during the day) ; causes greater evaporation / some water vapour loss through leaf surface all the time

Question 44

Q

pulse

Answer

A

fluxtuations in heart rate

Question 45

Q

changes in pressure of blood as it flows throught eh circulatory sustem from aorta to veins

Answer

A

marks for pressure change: pressure drops, as distance from heart increases ;

greatest / rapid / significant, pressure drop while blood is in the arteries ; pressure, constant / does not drop, in veins ;

       marks for amplitude of fluctuations: fluctuation / AW, decreases from aorta to arteries ;

no fluctuation in, capillaries / veins ;

use of comparative figures with unit ;

Question 46

Q

why important that pressure changes as blood flow from aorta to capp

Answer

A

blood flows into larger number of vessels ;

(total) cross-sectional area of the arteries is greater than the aorta ; (total) cross-sectional area of the capillaries is greater than the, aorta / arteries capillary (wall) is, thin / only one cell thick ; (high pressure would) burst / damage, capillary (wall) ; reduce chance of, tissue fluid build up / oedema

Question 47

Q

expiration

Answer

A

between B & C expiration:

1 (external) intercostal muscles / diaphragm, relax ;

2 rib cage / ribs, move down OR diaphragm, moves / pushed, up ; 3 volume of, thorax / chest cavity / lungs, drops / decreases ; 4 pressure inside, thorax / chest cavity / lungs, increases ; 5 above, external / atmospheric, pressure ; 6 air leaves down pressure gradient ; 7 (elastic) recoil of alveoli ;

Question 48

Q

describe phloem active loading

Answer

A

1 hydrogen ions / H+ / protons, pumped out of companion cells ; 2 increases, hydrogen ion / H+ / proton, concentration (gradient) (outside companion cell) ;

3 hydrogen ions, re-enter / flow back into, companion cells ; 4 sucrose / sugar, moves with hydrogen ions / AW ;

5 down concentration gradient ; 6 ref. cotransporter proteins / cotransport(ation) ; 7 by facilitated diffusion ;

8 sucrose / sugar, diffuses into sieve tube (element) ;

9 through plasmodesmata ;

Question 49

Q

why delay netweem atria excitation and ventricular excitation

Answer

A

(to allow time) for the atria to (fully) contract ;

to allow (time for), atria to empty / blood to move / ventricles to fill ; so that ventricle(s) do not contract, too early ;

Question 50

Q

why is wave of excitation carried tot the apex

Answer

A

so that (ventricular) contraction starts at, apex / base / bottom ;

to push blood upwards OR into/ towards, (named) arteries ;

complete / efficient, emptying of ventricles ;

Question 51

Q

need for cartilage in the trachaea

Answer

A

(provides) strength / support, to keep, it / trachea / airway, open OR (provides) strength / support, to prevent collapse ;

during, inspiration / inhaling / breathing in ;

volume of, chest cavity / thorax / lungs, increases ;

low(er) / negative, pressure in, trachea / thorax / lungs

Question 52

Q

why xylem needs ignin

Answer

A

provides, strength / support ;

to keep, it / the vessel / the tube, open OR prevent collapse of, vessel / tube ;

(because) transpiration produces, tension / negative pressure ;

to waterproof the, cell / vessel / tube / wall ;

(so) cell, dies / content decays ;

to create a hollow, tube / vessel OR to create a continuous column / allow unimpeded flow ;

to limit lateral flow of water ;

ref to adhesion (between water molecules and wall) ;

Question 53

Q

where can water be lost from th plant

Answer

A

aerial parts of the pant

cuticle

Question 54

Q

how aveoli adapted fro gas ex

Answer

A

wall is one cell thick for short(er) diffusion, distance / pathway ;
squamous, cells / epithelium , provide short diffusion distance / pathway ;
elastic so, recoil / expel air / helps ventilation ;
create / maintain, concentration gradient / described ;
large number (of alveoli) provide large(r) surface area ;
small size (of alveoli) provide large(r) surface area to volume ratio ;
(cells secrete) surfactant to maintain surface area ; max 4

Question 55

Q

babies lungs

Answer

A

lungs not, functioning / filled with air ;

blood / haemoglobin, is, not oxygenated in the lungs / oxygenated in placenta ;

(therefore) pulmonary circuit / lungs, bypassed ;

Question 56

Q

think of the ballon model of the lungs, why do the ballons expand?

Answer

A

1 volume, inside / of, jar increases ;

2 pressure inside, jar / balloons, decreases ;

3 to below pressure in atmosphere ;

4 (therefore) air, moves / pushed / forced, into, balloons / glass tube ;

Question 57

Q

what is tidal volume

Answer

A

volume of air, inhaled / exhaled ;

in, one / each, breath ;

during, steady / regular, breathing ;

Question 58

Q

how could the teacher use the ballon model to show tifal volume

Answer

A

up / down, movements (of rubber sheet / band) ;

idea of: small / steady / regular, movements (of rubber sheet) ;

Question 59

Q

what is vital capacity

Answer

A

the maximum volume of air ;

inhaled / exhaled, in one breath ;

Question 60

Q

how could the teacher use the ballon model to show vital capacity

Answer

A

idea that pulled down on rubber, sheet / band, as far as possible and pushed up as far as possible ;

Question 61

Q

why tissue fluid doesn’t contain rbc?

Answer

A

gap(s) between endothelium cells (too) small ;

(erythrocytes) too large / cannot change shape (much) ;

to, fit / move / pass, between (endothelium) cells OR through, gaps / pores / fenestrations;

Question 62

Q

describe the rle of haemoglobin in oxygen transportation

Answer

A

1 (haemoglobin has) high affinity for oxygen ;

2 oxygen binds to haemoglobin in, lungs / alveoli / high pO2 ;

3 oxyhaemoglobin ;

4 oxygen released, in tissues / where needed / where pO2 is low / where respiration is occurring

Question 63

Q

how are the HC03- made in the RBC

Answer

A

1 carbon dioxide, enters / diffuses into, erythrocytes ;

2 (carbon dioxide) combines / reacts, with water ;

3 correct ref to carbonic anhydrase;

4 forms carbonic acid ;

5 (carbonic acid) dissociates to form hydrogencarbonate ions and, hydrogen ions / protons ;

Question 64

Q

high co2 con in the blood reduces o2 transported by haemoglobin. what is this effect called and why does It happen?

Answer

A

1 Bohr (effect / shift) ;

Explanation (any 2 of the following marks)

2 reduces affinity (of Hb) for oxygen ;

3 formation of haemoglobinic acid / hydrogen ions interact with haemoglobin ;

4 prevents, fall in pH / build-up of H+, in cells OR provides buffering effect ;

5 alter, structure / shape, of haemoglobin ;

6 more oxygen released where, needed / more respiration / carbon dioxide concentration high ;

7 CO2 binds to haemoglobin forming carbaminohaemoglobin

Answer 65

A

many / large, mitochondria ;

plasmodesmata (between companion cell and sieve tube) / described ;

many ribosomes / extensive RER ;

many proteins in the, plasma / cell surface, membrane ;

Answer 66

A

arge plants) have a, small / low, SA : VOL ratio ;
idea of diffusion too slow (to supply requirements) ;

idea of need transport system (for water / minerals / assimilates) ;
idea of need (special) surface area for, gaseous exchange / uptake of minerals

Answer 67

A

short(er) diffusion, distance / path ;

Answer 68

A

high/ large / steep, concentration gradient OR removes oxygen (from lung surface) / brings carbon dioxide (to lung surface);

Answer 69

A

high / large / steep, concentration gradient OR supplies oxygen (to alveoli) / removes carbon dioxide (from alveoli) ;

Answer 70

A

large(r) surface area ;

Answer 71

A

this is where cambium / meristem / xylem / phloem / vascular bundle, is found ;

mitosis/cell division, occurs in cambium (to produce new cells for growth) ; new cells, differentiate / specialise, (into xylem and phloem) ; xylem supplies water for, (cell) elongation / (cell) growth ; phloem supplies, sugars / assimilates, for, energy / growth /respiration

Answer 72

A

allow oxygen to reach, cells / tissues (under bark) ;
for (aerobic) respiration ;
animals transport oxygen in, blood / circulation / transport system ; plants do not transport (much) oxygen in transport system ;
idea that (oxygen not supplied from leaves as) stomata only open in day / no leaves in winter ;

Answer 73

A

(fetal) haemoglobin may not crystallise (much) (at low pO2) ;
red blood cells do not change shape ;
(fetal) haemoglobin can pick up more oxygen at low pO2 (than sickle haemoglobin);

idea that more oxygen, transported / delivered (around body) ;

Answer 74

A

iffusion ;

from high concentration to low concentration / down concentration gradient;
(hydrostatic) pressure in capillary high(er than in tissue fluid) ; capillary (walls) leaky / described ;

fluid / plasma, forced out (of capillary) OR fluid / plasma, moves, from higher pressure to lower pressure / down pressure gradient ;
(as the fluid / plasma moves out) glucose / oxygen / small molecules, leave with, fluid / plasma ;

Answer 75

A

transpiration loss of water vapour / evaporation of water ; from, aerial parts of plant / leaves / stomata ;
transpiration stream movement of water (up xylem vessels) ; from roots to, leaves / air surrounding leaves ;

Answer 76

A

1 contain , (named) pigment (molecules) / photosystems ;

2 contain , (named) electron carriers / ETC / ATP synth(et)ase ;

3 idea that has a large surface area (in a small volume) for , light absorption / light dependent reaction(s) / light dependent stage / electron transport ;

Answer 77

A

at high light intensity other (named) factor becomes a limiting factor ;

2 idea that temperature becomes limiting as , Calvin cycle / light independent reaction , involves enzymes / relies on kinetic energy of molecules ;

3 idea that CO2 (concentration) becomes limiting as it is required for , Calvin cycle / light independent reaction / formation of (named) Calvin cycle compound / reaction with RuBP / fixation by Rubisco ;

Answer 78

A

shade leaf will have 1 large(r) / more , chloroplast(s) / (palisade) mesophyll ;

2 more , grana / thylakoids (in chloroplast) ;

3 large(r) surface area (of leaves) ;

Answer 79

A

1 glucose , respired / phosphorylated / metabolised , to produce ATP ;

2 ATP , blocks / closes , potassium ion channel(s) and potassium ions / K+ , build up (inside cell) / cannot leave ;

3 (voltage-gated) calcium ion / Ca2+ , channels open and calcium ions / Ca2+ , enter (cell by diffusion) ;

4 (more) calcium ions / Ca2+ , resulting in , movement of vesicles to membrane / exocytosis / described ;

Answer 80

A

1 (continues to be secreted) as long as blood / plasma , glucose (concentration) , remains high / is higher than normal ;

2 (sufficient) ATP is still present and so K+ channels remain closed ;

3 (exocytosis) still being triggered by , calcium ions / Ca2+;
2

Answer 81

A

1 some ATP used to (actively) transport pyruvate (into the mitochondrion) ;

2 some ATP used to (actively) transport H(+) from (reduced) NAD , formed in glycolysis / into the mitochondrion ;

3 some energy released in ETC , is not used to transport H+ (across inner membrane) / is released as heat ;

4 not all the H+ movement (back across membrane) , is used to generate ATP / is through ATP synth(et)ase ;

5 not all the, reduced NAD / red NAD / NADH , is used to feed into the ETC ;

Answer 82

A

1 glycolysis / conversion of glucose into pyruvate , occurs ;

2 produces 2 molecules of ATP (net) ;

3 (only) substrate level phosphorylation (occurs) ;

4 oxygen not available as final electron acceptor ;

5 pyruvate / ethanal , used to regenerate NAD for glycolysis (to continue) ;

6 (Krebs cycle and) electron transport chain / chemiosmosis / oxidative phosphorylation , do not occur ;

Answer 83

A

uncertain diagnosis because idea that older people may have more complex medical problems

Answer 84

A

it can perform , active transport / facilitated diffusion ;

Answer 85

A

1 idea that (dialysis is replicating function of kidney and) part of kidney’s function is to remove (excess) water from blood ;

2 (dextrose / sugar) reduces , water potential /  (of dialysis fluid) or (dextrose / sugar , solution) has a lower , water potential /  (than water) ; 3 water moves from blood (into dialysis fluid) by osmosis or prevents water moving into the blood (from dialysis fluid) by osmosis ;

4 (if it was water alone) cells would , swell / burst ;

Answer 86

A

1 peritoneal dialysis can remove less (named) waste (than haemodialysis) ;

2 idea that in haemodialysis dialysis fluid is constantly , refreshed / changed (but not in peritoneal dialysis) ;

3 haemodialysis uses counter-current flow ;

4 idea that haemodialysis maintains concentration gradient or in peritoneal dialysis the concentration gradient , reduces / is lower ;

5 (in peritoneal dialysis) the fluid reaches equilibrium with the blood

Answer 87

A

stem / erythropoietic , cell(s) and bone marrow ;

Answer 88

A

both have

1 dendrite(s) ;

2 an axon ;

3 a cell body with a , nucleus / named organelle ;

4 myelin sheath / myelinated / (covered with) Schwann cell / nodes of Ranvier ;

5 voltage-gated channels / sodium-potassium (ion) pump

Answer 89

A

1 evaporation will , have a cooling effect / reduce (body) temperature ;

2 heat , taken from / supplied by , the body / blood / skin , is , needed / used for , evaporation ;

3 idea that water has a high latent heat of , vaporisation / evaporation

Answer 90

A

idea that to increase body temperature as it is lower than the ‘new’ set-point (even though body is hot) ;

Answer 91

A

1 vasodilation results in more blood nearer to the skin surface ;

2 idea that will lose (even) more heat / further heat loss (from body) / body temperature decreases further ;

3 (named) organ(s) will not be able to maintain , function / metabolism ;

Answer 92

A

chlorophyll A

Answer 93

A

chlorophyll b / xanthophyll(s) / carotenoid(s) / ( / beta-) carotene

Answer 94

A

able to , absorb / use , a range of / different / more / other , (light) wavelengths /

Answer 95

A

starch / amylose / amylopectin and cellulose

Answer 96

A

it converts energy (mechanical) into , another / different , form of energy (electrical)

Answer 97

A

idea that deformation of membrane will allow more Na+ through because

1 (the increased pressure) causes sodium (ion) channels to open ;

2 (temporary) gaps / holes / spaces , appear , between the phospholipids / in the bilayer ;

Answer 98

A

if the , stimulus is not strong enough / threshold (value) is not reached / depolarisation (of membrane) is insufficient , then , it / an action potential , is not , generated / AW

Answer 99

A

1 idea that it is represented by the frequency of the action potentials ;

2 high , frequency / rate (of generation) , of action potentials shows , a strong / an intense , stimulus ; ora
2

Answer 100

A

action potentials not generated because

1 sodium (ion) channels (remain) open / resting potential not re-established ;

2 idea of ions being in the wrong place for correct ion movement (across membrane) ;

Answer 101

A

1 allows , neurones to communicate / cell signalling ;

2 ensure transmission (between neurones) in one direction (only) ;

3 allows , convergence / impulses from more than one neurone to be passed to a single neurone ;

4 allows , divergence / impulses from a single neurone to be passed to more than one neurone ;

5 idea that filters (out) , ‘background’ / low level , stimuli or ensures that only stimulation that is strong enough will be passed on ;

6 prevents fatigue / prevents over-stimulation ;

7 allows many low level stimuli to be amplified ;

8 idea that presence of inhibitory and stimulatory synapses allows impulses to follow specific path ;

9 permits , memory / learning / decision making ;

Answer 102

A

idea that time needed , to restore normal (blood) glucose concentration / for insulin to act (fully) ;

Answer 103

A

patient might have had a drink containing sugar ● patient was nervous and secreted adrenaline ● other medication interferes with glucose levels ● patient’s haemoglobin does not bind effectively with glucose (e.g. anaemia / sickle cell)

Answer 104

A

when blood glucose concentration decreases

1 (glucagon) released by the , alpha / , cells in , islets of Langerhans / pancreas ;

2 promotes / AW , conversion of glycogen to glucose / glycogenolysis , in , liver / muscle / effector , cells ;

3 ref gluconeogenesis / described ;

4 ref conversion of triglycerides to (free) fatty acids / lipolysis / increased use of fatty acids in respiration ;

5 negative feedback , reduces / inhibits , the secretion of glucagon ;

6 glucagon , reduces / inhibits , insulin secretion ;

Answer 105

A

if blood glucose falls , extremely / dangerously / too / very , low ;

2 if patient , cannot produce (enough) glucagon / produces little glucagon ;

3 idea that glucose source cannot be taken by mouth ;

difuctional alpha cells
dysfuction glycagon receptors

Answer 106

A

acetylcholine

Answer 107

A

hepatocytes

and

mitosis / mitotic (division) ;

Answer 108

A

1 idea that parasites have little access to oxygen ;

2 (inaccessible because) little oxygen dissolved in plasma / oxygen not very soluble (in plasma) ;

3 (inaccessible because) idea that oxygen is , combined with haemoglobin / contained in red blood cells ;

4 idea that haemoglobin has greater affinity for oxygen than parasite (pigment) ;

Answer 109

A

in animals A1 pyruvate is , converted / reduced , to , lactate / lactic acid ;

A2 can be reversed as no , atoms lost / other product formed ;

A3 lactate dehydrogenase available to reverse the reaction ;

in yeast Y1 pyruvate converted to ethanol (in 2 steps) and carbon dioxide / CO2 ;

Y2 cannot be reversed as , carbon dioxide is / atoms are , lost ;

Y3 (de)carboxylase enzyme cannot reverse the reaction

Answer 110

A

ANABOLIC steriods

Answer 111

A

It is longer.1 more (sodium and chloride) ions pumped , out of ascending limb / into medulla ;

2 builds up greater water potential gradient ;

3 allows , reabsorption / removal , of more water from , collecting duct / M ; therefore small amount of concentrated urine.

Answer 112

A

named component of cigarette smoke (correctly linked to a stated problem) ;

tar, hydrogen cyanide, carbon monoxide (but NOT in context of Hb), ammonia, sulphur dioxide destroy / paralyse , cilia ; mucus not removed ;

tar over-active goblet cells / extra mucus produced ;

(accumulation of mucus) leads to , infections / bronchitis ;

neutrophils / phagocytes / macrophages / monocytes (invade) ; secrete , enzyme / elastase ; elastin / elastic fibres , digested / destroyed ; low(er) level of , elastase inhibitor /  antitrypsinase ; alveoli fail to recoil ;

constriction of (terminal) bronchioles ; (so) coughing / forced expiration , causes alveoli to burst ; reduced surface area ;

Answer 113

A

shortness of breath / shallow breathing / strained breathing / hard to breathe out / wheezing ; barrel chest ; fatigue / extreme tiredness / cannot exert themselves ; pulmonary hypertension / high blood pressure to lungs ; enlargement of right side of heart ; heart failure / congestive cardiac failure / fluid buildup in lungs ; cyanosis / skin with blue tinge ;

Answer 114

A

long term / lifelong / persistent ; slow onset / takes time for the symptoms to show ; (usually) degenerative / gets (progressively) worse

Answer 115

A

1 coronary heart disease / CHD / atherosclerosis / angina / coronary thrombosis / myocardial infarction / heart attack / cardiac arrest / cardiovascular disease / stroke ;

2 (osteo)arthritis ; 3 (Type 2) diabetes ; 4 high blood pressure / hypertension ; 5 gallstones ; 6 cancer ;

Answer 116

A

excretion (metabolic) waste or toxin / harmful or substance is to be removed from body or does not use vesicles urea / carbon dioxide / water / bile pigment /

secretion useful product or used in cell communication (e.g. to target tissues) or released from glands (ducts or ductless) or uses vesicles or remain in body hormone / enzyme / antibodies / mucus / bile salts / neurotransmitter /

but both requires ATP or (involved in) homeostasis or (compounds) produced by cell(s) / produced by metabolism / need to cross membrane / need to move through membrane / need to leave cell / (may be) transported in blood

Answer 117

A

glucose is not the only substrate / there are other substrates ; named alternative substrate ; or ATP is produced / energy is released ; (by) substrate level / oxidative, phosphorylation ; or ATP / energy, required ; (for) phosphorylation / glycolysis ; or is not a single step reaction / other steps involved / other products / other intermediates ; named stage(s) / named intermediate compound(s) ; or enzymes are involved ; dehydrogenation / decarboxylation / oxidative phosphorylation / named (respiratory) enzyme ; or coenzymes / NAD, involved ; oxidative phosphorylation / link reaction / Krebs cycle / glycolysis ; or glucose does not, combine / react , (directly) with oxygen ; (oxygen) used in oxidative phosphorylation / is final electron acceptor / is final hydrogen acceptor ;

Answer 118

A

unable to produce (enough) insulin / do not secrete insulin / produces ineffective insulin ; insulin-producing cells / beta cells / islets of Langerhans, not functioning (correctly) / damaged / destroyed / attacked ;

by (body’s own) immune system / by (body’s own) antibodies / auto-immune disease ; (idea of) family history / genetic / hereditary ; (condition can be) triggered by , virus / environmental factor ;

Answer 119

A

increasing age / older / ageing / more prevalent over 40 ; (idea of) family history / genetic / hereditary ; (more common in) males ; (more common in) some ethnic groups / African / Afro-Caribbean / Asian / Hispanic / Oceanic ; obese / overweight / fat around abdomen ; high / frequent, intake of , sugar / highly processed food / high GI food ; lack of physical activity / sedentary lifestyle ; high blood pressure ; excessive alcohol intake ;

Answer 120

A

(pyruvate / F) converted to lactate ;

F / pyruvate , accepts hydrogen (atoms) ;

hydrogen from , reduced NAD / reduced E ; (catalysed by) lactate dehydrogenase ;

no, oxygen / O2 , to act as (final), hydrogen / electron, acceptor ; (so) link reaction / Krebs cycle / ETC, cannot take place ;

NAD / E, regenerated / recycled / able to be re-used ; allows glycolysis to continue / pyruvate continues to be made ;

limited / small amount of / some, ATP can be produced

Answer 121

A

large nostrils (open) to take in air ;

(when submerged) nostrils close / nose closes , to , keep air in / stop air from escaping ;

lungs / airways , have high (vital) capacity ;

links to respiration idea that seal , has low(er) metabolic rate / has low(er) respiratory rate / has low(er) energy requirements / uses (relatively) little ATP ;

able to respire anaerobically for a long time / more glycolysis ; large supplies of NAD (to accept H) ; (this) prevents , build-up of lactate / lowering of pH ; idea that (seal) tolerates lactate / removes lactate quickly ; idea that (seal) tolerates high CO2 concentration ; idea that (seal) tolerates low pH / has more pH buffers ; synoptic / inference idea that blood diverted from certain regions / certain regions have reduced metabolic activity ; idea that has plenty of , haemoglobin / red blood cells / myoglobin (as oxygen source) ; idea that haemoglobin has a higher affinity for oxygen / dissociates less readily / dissociation curve shifted to left ;

Answer 122

A

increased kinetic energy / KE so,  ions diffuse, across (axon) membrane / into neurone / into cell / between nodes / along neurone, more quickly or  faster movement of (neurotransmitter) vesicles / exocytosis (of neurotransmitter) or  neurotransmitter diffuses more quickly across,
synapse / synaptic cleft or  neurotransmitter (ACh) broken down by enzyme (acetylcholinesterase) more quickly ;

faster diffusion of ions leads to,  faster depolarisation or  shorter duration of action potential or  shorter refractory period or  faster repolarisation ;

Answer 123

A

ion, channels / pumps, disrupted / denatured / no longer function ; fluidity of, membrane / phospholipid / bilayer, disrupted ; (named) synaptic enzymes denatured ;

Answer 124

A

calcium channels open ;

Ca2+ / Ca++ / calcium ions , enter / diffuse into, acetylcholine / ACh / neurotransmitter, in vesicle(s) ;

(synaptic) vesicles move towards presynaptic membrane ; vesicles fuse with membrane ; release acetylcholine, by exocytosis , into synaptic cleft ;

Answer 125

A

ultrafiltration

Answer 126

A

(cuboidal) epithelium / epithelial ;

Answer 127

A

so that clots don’t form, while in the (dialysis) machine / during dialysis ;

Answer 128

A

idea of allowing blood to clot normally after treatment

Answer 129

A

(simple) diffusion

Answer 130

A

idea that it, maintains diffusion gradient / maintains concentration gradient / maximises diffusion gradient / maximises concentration gradient / allows maximum removal of waste / allows maximum rate of diffusion / AW ;

Answer 131

A

chlorophyll a ;

Answer 132

A

idea that ATP produced / energy released ;

idea that recycles NAD / NAD can be used again ;

allows , glycolysis / description of glycolysis , to take place / to continue

Answer 133

A

take place in different , parts / organelles , of the cell or compartmentalisation / reactions separated by membranes ;

W / glycolysis , in cytoplasm ;

X / Calvin cycle , in , chloroplast / stroma (of chloroplast) ;

Y / Krebs cycle , in , mitochondrion / matrix (of mitochondrion) ;

Answer 134

A

ATP / adenosine triphosphate ; water / H2O ; (oxidised) NAD / FAD ;

Answer 135

A

water potential /  , of plasma / outside cells , would be higher than that of the (blood) cells ;

water would enter (blood) cells ;

blood cells , swell / (might) burst / lyse

Answer 136

A

in , liver / hepatocytes ;

hydrolysis / acted on by protease ;

deamination / amine group removed / formation of ammonia / formation of NH3 ;

ornithine cycle / formation of urea / formation of CO(NH2)2 ;

amino acids / keto acids , used in (named) metabolic pathway ;

how ADH or urea is dealt with as a small molecule in kidney ;

(ultra) filtered from blood / moves from blood into nephron ;
(because) small molecule ;

urea not (all) reabsorbed / ADH not reabsorbed / (ADH or urea) present in urine ;

excreted ;

Answer 137

A

adrenalin(e) increases , heart rate / stroke volume / cardiac output ;

cardiovascular centre in medulla oblongata ;

idea of nervous connection to , SAN / sino-atrial node ; (which) controls frequency of waves of , excitation / depolarisation ;

vagus / parasympathetic , nerve decreases heart rate ; accelerator / sympathetic , nerve increases heart rate ;

high blood pressure detected by , stretch receptors / baroreceptors ; low blood pH / increased levels of blood CO2 , detected by chemoreceptors ;

(receptors) in , aorta / carotid sinus / carotid arteries ;

Answer 138

A

peripheral / skin , thermoreceptors / (heat) receptors , stimulated (by decrease in external temp) ; (impulses sent to / blood temperature monitored in ) hypothalamus / sensory cortex ;

vasoconstriction of , arterioles / small arteries , to reduce heat loss ;

(prevents heat loss by) radiation / conduction / convection ;

increased , metabolic rate / metabolism / respiration , to generate heat (energy) ; (release of) adrenaline / thyroxine ; shivering / (involuntary) muscle spasms , to generate heat (energy) ;

erector / hair , muscles raise , (skin) hair / fur , to trap , air / heat ;

Answer 139

A

(testing for) human chorionic gonadotrophin / hCG ; hormone small so can pass from blood into filtrate (at Bowman’s capsule) ;

monoclonal / immobilised , antibodies / immunoglobulin , on stick ; antibodies attached to , marker / dye ; hormone , binds / complementary , to antibody ; (triggers) appearance of colour / line becomes visible ;

AVP ;
3

Answer 140

A

regenerates / produces , ribulose bisphosphate / RuBP ; so cycle can continue / for (further) CO2 fixation / to combine with CO2 ;

formation of (named) , sugar / glucose / hexose / sucrose / starch / cellulose ;

formation of (named) , fat / triglyceride / lipid / fatty acids / glycerol / amino acids / protein / nucleic acids / nucleotides ;

10x TP for RuBP and 2x TP for production or most TP used to produce RuBP and the rest for production

Answer 141

A

oxygen used and carbon dioxide , produced / excreted ;

(only) occurs in the light / light (energy) required or uses , (same) photosynthetic enzyme / Rubisco or involves Calvin cycle ;

Answer 142

A

reduces (rate of) photosynthesis / increases (rate of) photorespiration ;

less Rubisco available for CO2 / more oxygen competing with CO2 for Rubisco / more O2 binding to Rubisco O 2 outcompetes CO2 for Rubisco ;

less CO2 , fixation / for Calvin cycle ; CO2 given off ;

less , glycerate 3-phosphate / GP / TP , produced ; less RuBP , regenerated / formed ;

Answer 143

A

starch contains (only) glucose and sucrose contains , 50% glucose or glucose and fructose ;

by hydrolysis , starch releases more glucose / sucrose releases less glucose

Answer 144

A

both starch and cellulose are (only) made of glucose ;

starch , is digestible / can be broken down and cellulose , is indigestible / cannot be broken down ;

(named) enzyme present for starch digestion / no (named) enzyme present for cellulose digestion

Answer 145

A

low / decrease , starch ;

as starch has the greatest effect on blood glucose conc. ;

increase / include , cellulose / fibre / roughage / fat / protein / meat , as no effect on blood glucose ;

some / medium amount of , sugars / sucrose / lactose ;

idea of limiting , sucrose / lactose / fat / protein , as causes an increase in insulin and will make cells less responsive (to insulin)

Answer 146

A

glycogen carbohydrate OR polysaccharide

role of compound storage OR to provide glucose (when blood glucose conc. falls) OR can undergo glycogenolysis

site of production liver OR hepatocytes

glucagon
hormone OR polypeptide OR protein

role of compound
binds to cell receptor OR causes conversion of glycogen to glucose OR stimulates glycogenolysis OR increases (blood) glucose concentration

site of production
pancreas OR islets of Langerhans OR alpha / α , cells

Answer 147

A

attacked by the body’s (own) immune system ;

(immune system) mistakes / treats / recognises , body cells / neurones / myelin , as , ‘foreign’ / non self ;

correct ref. to , antibodies / (named) phagocytes / (named) B lymphocytes / (named) T lymphocytes

Answer 148

A

damage to) myelin / sheath / Schwann cell(s) ; removes / has less , insulation ;

interferes with / slows / stops , conduction of , (nerve) impulse / action potential or slows / stops / prevents , saltatory conduction / described ;

occurs , in sensory neurones / towards brain / towards CNS / from sensory organ / from receptor

Answer 149

A

1 idea of  maintaining (relatively) stable internal ,    environment / state ;
2 within (narrow) limits / within (narrow) range /     about a set point ;

3 even though environment is changing

Answer 150

A

 cells /  cells / receptors , detect , change / increased / decreased , in blood glucose (concentration) ;

2 if high(er) glucose (concentration) , beta /  , cells (in pancreas) release insulin ;

3 (increased) uptake / absorption , of glucose by , liver / muscle / effector , cells ;

4 enters through glucose transport proteins (in cell surface membrane) ;

5 glucose converted to glycogen / glycogenesis ;

6 increased (use of glucose in) , respiration / ATP production ;

7 if low(er) glucose (concentration) , alpha /  , (in pancreas) cells release glucagon ;

8 (increased) conversion of glycogen to glucose / glycogenolysis ;

9 (increased) conversion of other compounds (amino acids / lipids) to glucose / gluconeogenesis ;

10 glucose leaves cells , by facilitated diffusion / through glucose channels ;

Answer 151

A

(high intake of protein) leads to a large amount of amino acids ;

2 (excess) amino acids cannot be stored ;

3 amino acids deaminated or amine group / NH2 , removed / converted to ammonia ;

4 (large amount of) ammonia enters ornithine cycle (for conversion to urea) ;

5 increased , blood / plasma , concentration of urea (leads to more urea in , filtrate / urine) ;

6 high concentration of , amino acids / urea , in blood increases water absorption from urine

Answer 152

A

B
B
B
N
N
C

Answer 153

A

link reaction and Krebs cycle ;

Answer 154

A

oxidative phosphorylation

Answer 155

A

1 afferent arteriole , has diameter greater than that of / is wider than , efferent arteriole ;

2 build up of / high , hydrostatic / blood , pressure ;

3 endothelium / wall , of , capillary / glomerulus , has , (small) pores / fenestrations ;

4 (these allow) ultrafiltration

Answer 156

A

if kidney cannot filter so substances remain in blood 1 increase / high , in urea ; 2 increase / high , in , (named) ions / (named) salts ; 3 increase / high , in water ; 4 AVP ;

OR

if problems cause substances to be lost indiscriminately 5 decrease / low , in , protein / blood cells ; 6 decrease / low , in , (named) ions / (named) salts ; 7 decrease / low , in , glucose / amino acids / vitamins ; 8 decrease / low , in water ;

Answer 157

A

if not closely matched

1 donated kidney will be recognised as , foreign / non-self ;

2 antigens / glycoproteins , (on donated kidney) will be different ;

3 causing rejection ;

4 (response) by immune system ;

5 use of immuno-suppressant drugs ;

6 ref to need for suitable size in specific case (e.g. if recipient is a small child

Answer 158

A

the motor neurone - structure the cell body is at (one) end of the , neurone / cell or the cell body is in , brain / spinal cord / CNS or dendrites connected (directly) to cell body or long(er) axon or no dendron or axon , connects to / ends at , effector / motor end plate ;

Answer 159

A

the motor neurone - function carries , impulse(s) / action potential(s) , from , brain / spinal cord / CNS / relay neurone or carries , impulse(s) / action potential(s) , to , effector / muscle / gland

Answer 160

A

pumping / active 1 sodium-potassium pump , uses ATP / uses energy / by active transport / (pumps) actively ;
2 pumps / actively moves , sodium ions / Na+ , out of , cell / axon / neurone , and , potassium ions / K+ , in ;
passive / diffusing 3 K+ , diffuse / move / flow / leak , (freely) back out (of cell) ;
4 membrane less permeable to Na+ / fewer Na+ channels open , so fewer Na+ , diffuse / move / flow / leak , back in ; ora

5 voltage-gated (Na+) , channels closed ;

6 AVP ;

Answer 161

A

1 idea that only stimuli , that reach / are greater than , threshold value / -50mV , produce an action potential ; ora

2 (when stimulated) action potential either occurs or does not / all-or-nothing (law) ;

3 idea that the action potential is the same (magnitude / size) , no matter how strong the stimulus / even if strength of stimulus increases ;

4 idea that a strong stimulus produces many action potentials (in rapid succession)

Answer 162

A

blood glucose (concentration) would fall , too low / below normal level ;

2 idea that glucose would continue to be taken up by , cells / liver / muscle (results in low blood glucose) or idea that glucose is continually converted into glycogen / would store too much glucose as glycogen ;

3 (mitochondria eventually) cannot , release enough energy / generate enough ATP (as less available glucose in blood) ;

4 coma / death ;

5 AVP ;

Answer 163

A

build-up of lactate / prevention of pathway S , poisons / kills , (liver) cells ;

2 disruption of enzymes as a result of low pH ;

3 idea that lack of substrate / fatty acids not available , for respiration ;

4 lack of (oxidised) NAD for (metabolic) reactions ;

5 (some) deamination / ornithine cycle / pathway P / breakdown of (named) hormones / pathway R , cannot occur ;

6 build-up of fatty acids / more fatty acids present , resulting in , fat deposits in (liver) cells / fatty liver / cirrhosis

Answer 164

A

crista(e) / inner mitochondrial membrane

Answer 165

A

for membrane formation or phospholipid / cholesterol / glycolipid , for membrane ;

fatty acid / (named) pigment , synthesis ;

Answer 166

A

(primary & accessory) pigments , are in / form a(n) , photosystem / complex / antenna complex ;

2 photon / light energy , absorbed by pigment (molecule(s)) ;

3 electron , excited / moves to higher energy level / delocalised , and returned to pigment ;

4 (energy / photon) passed from one pigment to another ;

5 (energy / photon) passed to , reaction centre / chlorophyll a / P680 / P700 / PS I / PSII / primary pigment ;

6 range of / accessory , pigments allow range of wavelengths to be absorbed ;

Answer 167

A

gluconeogenesis and glycogenolysis ;

Answer 168

A

glycolysis and glycogenesis ;

Answer 169

A

hydrostatic ;

water / urea / amino acids / vitamins / small proteins ;

ultrafiltration ;

water ;

capillaries / vessels

Answer 170

A

((walls of) blood vessels in) hypothalamus

osmoreceptor(s)

Answer 171

A

water potential of , plasma / blood , will , decrease / become more negative ;

(ADH secretion) will increase ;

Answer 172

A

M:S cell body in CNS

cell body , not in CNS / in PNS ;
2 cell body at end (of neurone)
cell body , not at end / in middle (of neurone)
;
3 dendrites connect directly to cell body
dendrites do not connect directly to cell body or dendrites at the end(s) of , dendron / axon
;
4 long(er) axon short(er) axon ; 5 dendron absent / no dendron dendron present ; 6 ends at motor end plate starts at / connects to , (sensory) receptor

Answer 173

A

60 to -70 ;

2 depolarisation ;

3 threshold potential / threshold value ;

4 all or nothing ;

5 size / magnitude ;

6 frequency ;

Answer 174

A

less ventilation / Idea of difficulty in exhaling due to less recoil / small surface area for gaseous exchange / less oxygen entering capillaries / less oxygen entering blood ;

2 less oxygen (reaching cells) for , (aerobic) respiration / oxidative phosphorylation ;

3 (so) less ATP produced ;

4 idea of increased acidity (as CO2 / lactate builds up) interfering with / affects , enzymes / respiratory metabolism

Answer 175

A

1 not enough / less , glucose uptake into cells ;

2 not enough / less , glucose / substrate , for , respiration / ATP production ;

3 glucose not , stored as / converted to , glycogen

Answer 176

A

1 idea of slow rate of / sluggish , blood flow or low(er) blood pressure ;

2 less / irregular amount of , oxygen (reaching cells) for , (aerobic) respiration / oxidative phosphorylation ;

3 less glucose (reaching cells) for respiration ;

4 (so) less ATP produced ;

5 idea of increased acidity (as CO2 / lactate builds up) interfering with / affects , enzymes / respiratory metabolism

Answer 177

A

endocrine H1 hormone(s) released directly into blood ; H2 beta / β , cells , secrete / produce / release , insulin ; H3 alpha / α , cells , secrete / produce / release , glucagon ;

H4 islet /  and  , cells , detect / monitor , blood glucose concentration ; 3 max exocrine E1 fluid / juice / secretion / enzymes , released into duct ;

E2 (release triggered by) nervous / hormonal , stimulation ; E3 pancreatic secretions into , gut / small intestine / duodenum ; E4 alkaline / pH 8 / (sodium) hydrogen carbonate ; E5 containing 2 named enzyme(s) ;

Answer 178

A

ultrafiltration ;

2 afferent arteriole is wider than efferent arteriole ;

3 high blood pressure in glomerulus / high(er) hydrostatic pressure in glomerulus (than in Bowman’s capsule) ;

4 idea that endothelium / wall of capillary , has gaps to , allow / prevent , passage (of substances / cells) ;

5 idea that basement membrane stops removal of , large molecules / cells ;

6 podocytes / epithelial cells of Bowman’s capsule , have (finger-like) projections / processes ;

7 (projections) ensure gaps to allow passage (of substances)

Answer 179

A

1 (large) protein / amino acids , present ;

2 blood (cells) present ; 3 glucose present ;

4 more water present / more dilute ; 5 more , ions / salts / electrolytes , present ; 6 (more) vitamins present ; 2

Answer 180

A

adrenal cortex ;

Answer 181

A

inner mitochondrial membrane / crista

Answer 182

A

cyclic photophosphorylation

Answer 183

A

(named) neurotransmitter / acetylcholine , released from pre-synaptic / first , cell / membrane ;

2 diffuses across , gap / cleft / synaptic cleft or reaches second , neurone / cell / membrane , by diffusion ;

3 attaches to , receptors / binding sites of sodium channels , on post-synaptic membrane / membrane of second cell ;

4 neurotransmitter / acetylcholine , broken down (in cleft) ;

Answer 184

A

ensures movement of , impulse / action potential , in one direction (only) ;

2 integration or one neurone can , connect to / receive impulses from / transmit impulses to , many neurones ;

3 allows summation ;

4 idea that filters out , ‘background’ / low level , stimuli or ensures that only stimulation that is strong enough will be passed on;

Answer 185

A

endotherm(s) ;

Answer 186

A

vaso)dilation

Answer 187

A

/ adrenaline;

Answer 188

A

hypothalamus

Answer 189

A

ascending (limb of loop of Henle
proximal convoluted tubule / 
collecting duct / distal convoluted tubule 
Bowman’s capsule /  renal capsule 
proximal convoluted tubule

Answer 190

A

2

3 4

5

6

7
role of loop of Henle is to cause a decrease in water potential in / establish water potential gradient going down , medulla ; (as) in ascending limb active transport outwards of , solutes / (sodium and chloride) ions ;

(walls of) descending limb permeable to water ; water removed from descending limb ;

water potential of tissues surrounding collecting duct is low(er) than fluid inside it ; water removed from , filtrate / urine (in collecting duct) ;

Answer 191

A

crista(e)

Answer 192

A

ethanal ;

Answer 193

A

releases NAD , to accept more H / to be reduced again / so glycolysis can continue or allows (some) ATP to be generated (in glycolysis) ;

2 (some ATP available) for named cellular process ;

Answer 194

A

ethanol and carbon dioxide

Answer 195

A

1 prevents photophosphorylation ; 2 cyclic and non-cyclic ;

3 no / less , ATP / reduced NADP , for , light-independent stage / Calvin cycle / GP to TP ;

4 no (named) substrate made for respiration

Answer 196

A

islet(s) of Langerhans ;

Answer 197

A

Insulin secretion is stimulated when the blood glucose concentration increases ;

Glucose enters the pancreatic cell through channel proteins. The glucose
enters the 2 glycolytic / glycolysis pathway and ATP
is produced.
The increase in ATP causes ATP-controlled potassium ion channels to close
and the cell membrane becomes depolarised ;This results in the opening of voltage-gated calcium ion channels and the concentration of this ion inside the cell increases.
The increased concentration of these ions causes the secretion of insulin from
the cell by the process of 5 exocytosis

Answer 198

A

ribosome / rough endoplasmic reticulum / RER ;

Answer 199

A

in myelinated neurones

1 conduction faster in myelinated neurone ; ora

2 depolarisation / action potential , can only occur where (voltage-gated / Na(+)) channels present ;

3 idea that myelinated neurones have long(er) sections with no, (voltage-gated / Na(+)) channels present ;

4 ion , movement / transfer , can only take place at the gaps / nodes ; ora

5 longer local circuits / fewer local circuits ; 6 saltatory conduction / action potential jumps from node to node ;

Answer 200

A

thermoregulatory centre in) hypothalamus

Answer 201

A

large surface area (to lose heat) ; (thin) so , blood flows / (named) blood vessel are , close to the (skin) surface (to lose heat) ; (movement) increases air movement over , skin / surface (to lose heat)

Answer 202

A

blood loses less heat because , less blood flows to feet / warm blood diverted from arterioles to veins

or less blood flows to feet so core body temperature maintained

Answer 203

A

1 large molecules / proteins / blood cells , cannot , leave blood / enter the filtrate or (named) small molecules can , leave blood / enter filtrate;
2 endothelium / fenestrations / basement membrane , prevents , large molecules / erythrocytes , reaching , renal / Bowmans capsule ;

3 all glucose / glucose completely , reabsorbed at the , proximal convoluted tubule / PCT ;

4 all amino acids / amino acids completely , reabsorbed at the , proximal convoluted tubule / PCT ;

5 (some / not all) ions , reabsorbed / move into blood (at any part of , nephron / tubule) ;

6 urea / ion , concentration increases (between filtrate and urine) because , movement (of urea / ion) into tubule / water removed

Answer 204

A

idea that (high creatinine concentration indicates) reduced function because , less filtration / low GFR

Answer 205

A

eneral 1 idea that people should have a right to choose (freely) what to do with their kidney ;

perceived donor advantages 2 idea that donors / donors’ families , can benefit from money raised (by selling a kidney) ; 3 people can donate a kidney to family member ; 4 idea that people can donate without payment ;

perceived donor disadvantages 5 idea of exploiting people’s poverty ; 6 idea of exploitation of , children / minors ;

recipient issues 7 idea that people should receive transplants irrespective of wealth ; 8 idea that it is wrong that recipients are being charged excessively

Answer 206

A

adrenaline / epinephrine / noradrenaline / norepinephrine

Answer 207

A

impulses along parasympathetic nerve / impulses along vagus nerve / nerve endings releasing acetycholine ;

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