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Page 1

Homeostasis

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA

Topic 4.5 Homeostasis and Response

Sub-Topic Homeostasis

Difficulty Level Bronze Level

Booklet Mark Scheme 1

Time Allowed: 54 minutes

Score: /54

Percentage: /100

http://www.savemyexams.co.uk/



Page 2

M1 (a) liver 1

(b) insulin

do not accept glucagon 1

(c) kidney 1

(d) to replace water / ions / salt 1

(that is) lost in sweat 1

[5]




Page 3

M2. (a) (i) (too) big 1

cannot fit / pass through filter / through (pores) in membrane / cannot be filtered

too big to be filtered = 2 marks 1

(ii) water 1

(iii) partially permeable 1

(b) any two from:

• hazards of operation / named eg

• may be rejected or need to use immunosuppressant drugs / long term drug use or transplant may need to be replaced

• susceptible to other infections

• shortage of donors

• high initial cost 2

[6]




Page 4

M3. (a) (i) kidney 1

(ii) bladder 1

(iii) liver 1

(iv) lung(s) 1

(v) skin 1

(b) (i) 3000

allow 2970 to 3030

correct answer gains 2 marks with or without working

if answer incorrect allow 1 mark for evidence of 1550 + 450 + 1000 (allow tolerance of + or – ½ square on each)

2

(ii) 1600

allow 1570 to 1630 1

(iii) 1400

allow (b)(i) – (b)(ii) 1

(iv) correct plot from (b)(iii)

tolerance ½ square ignore width 1




Page 5

(v) cells swell / overhydrated / damaged

accept poisoned (by urea) 1

[11]




Page 6

M4. (a) pancreas

allow phonetic spelling 1

(b) (i) A 1

shortest / quicker time (to work) 1

(ii) D 1

acts for longest time

mark dependent on D

allow D will last until 09.00 / breakfast / 24 hours 1

(iii) diet / exercise

if ‘diet’ is qualified, then will need correct qualification, e.g. ‘less carbohydrate / sugar’

accept pancreas transplant / stem cell treatment 1

[6]




Page 7

M5. (a) (i) water 1

(ii) small 1

(iii) 3.15 1

(b) (i) 21 000 1

(ii) 2 years 1

(iii) prevent rejection 1

[6]




Page 8

M6.(a) a higher concentration would be difficult to stir 1

(b) (i) methane 1

(ii) 60

100 - (5 + 35) but incorrect answer allow 1 mark 2

(c) (i) aerobic respiration 1

(ii) oxygen 1

[6]




Page 9

M7. (a) pancreas

apply list principle 1

(b) (i) protein


(ii) any one from:

• (controlling / changing) diet

accept sugar(y foods) / named eg

ignore references to starch / fat / protein / fibre

• exercise

accept example, eg go for a run

• pancreas transplant

accept named drug eg metformin 1

(c) (i) increase

ignore reference to women 1

then fall 1

relevant data quote (for male)

eg max at ages 65–74 or starts at 10 (per thousand) or max at 130 (per thousand) or ends at 120 (per thousand)

accept a difference between any pairs of numbers in data set

accept quotes from scale eg ‘130’ or ’130 per thousand’ but not ’130 thousand’; to within accuracy of +/- 2 (per thousand)

1

(ii) (between 0 and 64) more females (than males) or less males (than




Page 10

females)

ignore numbers

allow eg females more diabetic than males 1

(over 65) more males (than females) or less females (than males)

allow eg males more diabetic than females 1

[8]




Page 11

M8. (a) brain

in correct order only 1

blood 1

sweat 1

(b) (i) A 1

(ii) to replace ions lost (in sweat)

accept salts

allow named examples, eg. prevent cramps 1

(iii) any one from:

• there is too much glucose / sugar in the sports drink • they shouldn’t have too much glucose / blood sugar • it would cause their blood glucose / sugar to rise (too high)

1

[6]




Page 1

Homeostasis

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA

Topic 4.5 Homeostasis and Response Sub-Topic Homeostasis

Difficulty Level Silver Level



Score: /60

Percentage: /100



Page 2

M1.(a) detect changes in surroundings or detect stimuli

allow any named stimulus for skin 1

convert information to impulse

allow send impulse to sensory neurones / brain 1

(b) (i)

muscle contract(ion)

gland release / secrete / produce chemical / hormone / enzyme

1 mark for each effector

1 mark for each response

response must match type of effector (if given)

ignore examples

ignore relax(ation) / movement for contraction

do not allow expansion for muscles 4

(ii) any one from:

• (maintain temperature at which) enzymes work best • so chemical reactions are fast(est) • prevent damage to cells / enzymes

allow prevent enzymes being denatured (by temperature being too high)

1

[7]



Page 3

M2. (a) Y - spinal cord / central nervous system / CNS

do not accept spine

ignore nerve / nervous system / coordinator

ignore grey / white matter 1

W - receptor / nerve ending

ignore sensory / neurone / stimulus 1

X - effector / muscle

allow gland 1

(b) any two from: eg

accept reverse argument for each marking point

• reflex action quicker

• effect of reflex action over shorter period

• hormone involves blood system and reflex involves neurones / nerve cells

ignore nervous system / nerves

• reflex involves impulses and hormone involves chemicals

• reflex action affects only one part of the body

ignore involves brain

ignore outside / inside stimuli 2

[5]



Page 4

M3. (a) B 1

less / no insulin (produced) or insulin produced in pancreas

allow pancreas can’t monitor (blood) sugar (level)

ignore pancreas can’t control (blood) sugar (level)

allow increased glucagon production

allow A as liver stores less glucose / sugar for 2 marks only 1

(b) (i) (it / protein / insulin) digested / broken down

if ref to specific enzyme must be correct (protease / pepsin)

ignore denatured

do not accept digested in mouth / other incorrect organs 1

(ii) any two from:

ignore injections

• (attention to) diet

accept examples, eg eat less sugar(y food) or eat small regular meals

allow eat less carbohydrate / control diet

ignore cholesterol or balanced / healthy diet

• exercise

ignore keep fit / healthy

• (pancreas) transplant / stem cells / genetic engineering 2

[5]



Page 5

M4. (a) (i) any one from:

• chemical messenger / message

allow substance / material which is a messenger

• chemical / substance produced by a gland

allow material produced by a gland

• chemical / substance transported to / acting on a target organ

• chemical / substance that controls body functions 1

(ii) gland / named endocrine gland

brain alone is insufficient


(iii) in blood / plasma or circulatory system or bloodstream

accept blood vessels / named

do not accept blood cells / named 1

(b) each hormone must be linked to correct actionapply list principleignore the gland producing hormone

FSH stimulates oestrogen (production) / egg maturation / egg ripening

ignore production / development of egg 1

oestrogen inhibits FSH

allow oestrogen stimulates LH / build up of uterine lining 1

LH stimulates egg / ovum release / ovulation

accept LH inhibits oestrogen accept LH controls / stimulates growth of corpus luteum ignore production of egg

1



Page 6

[6]

M5. (a) (i) the lower the temperature the shorter the time

a trend is required

accept reverse

or

the lower the temperature the more chance of frostbite

accept the lower the temperature the faster you get frostbite

accept positive correlation but not directly proportional

ignore wind speed 1

(ii) any value from 5 to below 10

do not accept 10

allow less than 10 or < 10 1

(b) Muscles ‘shiver’

if more than two boxes ticked deduct 1 mark for each additional tick

1

Blood vessels supplying the skin capillaries constrict 1

[4]



Page 7

M6. (a) (i) A – pituitary

allow hypothalamus 1

B – ovary / ovaries 1

(ii) in blood (stream)

accept in plasma

ignore dissolved 1

(b) (i) FSH and Luteinising Hormone (LH) 1

(ii) fertilised OR reference to sperm

1

form embryos / ball of cells or cell division 1

(embryo) inserted into mother’s womb / uterus

allow (fertilised egg) is inserted into mother’s womb / uterus 1

(iii) any one from:

• multiple births lead to low birth weight

• multiple births cause possible harm to mother / fetus / embryo / baby / miscarriages

allow premature



Page 8

ignore reference to cost / ethics / population 1

(c) (i) any one from:

• almost identical

allow S (slightly) more successful

• both approximately 20% 1

(ii) larger numbers (in clinic R) (in 2007)

allow only 98 (in S) (compared to 1004 (in R)) 1

results likely to be more repeatable (in 2008)

allow more reliable

do not accept more reproducible / accurate / precise 1

[11]



Page 9

M7. (a) (i) without oxygen

ignore reference to ‘air’ 1

(ii) otherwise difficult to stir / to pump / to transfer

allow prevent ‘clogging’ owtte 1

(iii) need to stir / pump / heat 1

(b) (i) rises then falls 1

then levels / slight rise 1

quantitative descriptor - e.g. to 80% / max. on day 4 / min. on day 16

accept other valid quantitative descriptor

allow accuracy ± ½ small square 1

(ii) 16 (15.5 to 16.4) 1

(c) any two from:

• oxygen present

• (CO2 produced) by aerobic respiration

or not much anaerobic respiration

• not much methane / CH4 produced



Page 10

2

[9]

M8.(a) microorganisms

allow microbes / bacteria / fungi / decomposers 1

(microorganisms) respire

do not allow dead plants respire 1

(respiration / decay / microorganisms) releases (thermal) energy / ‘heat’

ignore produce ‘heat’

do not allow produce energy

do not allow dead plants release ‘heat’ 1

(b) (i) any three from:

• (opening) allows oxygen in • microorganisms / eggs need oxygen

allow air for oxygen

• oxygen needed for respiration • (opening) allows release of carbon dioxide (from microorganisms /

respiration / eggs)

allow gaseous exchange (1 mark) of / for microorganisms / eggs (1 mark) if none of first four points given

• (opening) allows energy / ‘heat’ to escape • (closing) retains energy / ‘heat’ if too cool / at night

if no mark awarded for either of these points allow 1 mark for vents open in the day to prevent overheating and close at night to prevent it getting too cold

• (closing) retains moisture

allow (opening) releases moisture 3

(ii) any one from:

• maintains sex balance

e.g. equal / best / correct numbers of male and female

• (survival of species depends on there being) males and females in population



Page 11

allow so the offspring are not all the same sex 1

[7]



Page 12

M9.Marks awarded for this answer will be determined by the Quality of Communication (QC) as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.

0 marks

No relevant content.

Level 1 (1 – 2 marks) There is a description of thermoregulation or at least one correct mechanism (skin,

sweat glands or muscles) but roles may be confused.

Level 2 (3 – 4 marks) There is a description of thermoregulation or some correct mechanisms (sweating,

shivering, blood flow in the skin).

Level 3 (5 – 6 marks) There is a clear description of thermoregulation by TC or skin and some correct

control mechanisms.

examples of biology points made in the response:

full marks may be awarded for detailed description of what happens if the core temperature is either too high or too low

• temperature receptors in TC • the TC detects (core) body / blood temperature • temperature receptors in the skin send impulses to the TC, giving information

about skin temperature • if the core body temperature is too high: blood vessels / arterioles supplying

the skin capillaries dilate / vasodilation

do not accept refs to veins instead of arterioles or answers that imply blood vessels have moved up / down through the skin.

• so that more blood flows (through the skin) and more heat is lost • sweat glands release more sweat to cool the body • by evaporation • if the core body temperature is too low: blood vessels supplying the skin

capillaries constrict • to reduce the flow of blood (through the skin) and less heat is lost

allow idea of blood diverted to vital organs in extreme cold • muscles may shiver to release (heat) energy



Page 13

• from respiration, some of which is lost as heat [6]



Page 1

Homeostasis

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA



Difficulty Level Gold Level



Score: /58

Percentage: /100




Page 2

M1. (a) (concentration high) in the hepatic portal vein is blood with glucose absorbed from the intestine

1

concentration is lower in the hepatic vein because insulin 1

(has caused) glucose to be converted into glycogen 1

or

allows glucose into liver cells

(b) (i) (after 6 hours) most of the glucose has been absorbed from the intestine or from food into the blood

1

(ii) because glucagon (made in the pancreas) causes

if biological terms incorrectly spelt they must be phonetically accurate

do not accept glucagon made / produced by the liver 1

glycogen to be converted into glucose 1

glucose released into blood

allow the liver maintains the correct / constant level of glucose in the blood

1

[7]




Page 3

M2. (a) in rainforest:

accept converse

(water from) sweat does not evaporate (as much)

max 1 if not clear whether desert or rainforest 1

any one from:

• (due to) less wind / higher moisture / humidity

• less cooling effect

ignore references to temperature 1

(b) blood vessels supplying capillaries dilate / widen or vasodilation

do not award mark if candidate refers only to blood vessels dilating or to capillaries dilating.

accept ‘arteries’ or ‘arterioles’ for ‘blood vessels supplying, capillaries’ but do not accept ‘veins’. ignore expand / get bigger / relax / open

do not accept idea of blood vessels moving 1

more blood (through skin / surface capillaries) leads to greater heat loss 1

[4]




Page 4

M3. (a) proteins are not filtered 1

glucose is filtered and (re)absorbed

allow glucose (completely) reabsorbed 1

ions are filtered and some (re)absorbed

allow some ions are reabsorbed 1

urea is filtered [and some / none (re)absorbed]

allow some / no urea is reabsorbed 1

(b) more / a lot of sweating occurred

accept converse arguments for cold day 1

more / a lot of water loss (by sweating) 1

more / a lot of water reabsorption / more water absorption by the kidney 1

lower volume of urine

allow less urine / less water in urine 1

[8]




Page 5

M4. (a) 0.18

award both marks for correct answer irrespective of working

if no answer or incorrect answer

allow 1 mark for 45 × 100 / 25000 2

(b) heat / thermal

allow heat from respiration 1

(c) energy / mass / biomass lost / not passed on or energy / mass / biomass is used or not enough energy / mass / biomass left

ignore reference to losses via eg respiration / excretion / movement / heat

1

a sensible / appropriate use of figures including heron

eg only 2 from frog / to heron

ignore units 1

(d) any three from:

accept marking points if candidate uses other terms for microorganisms

• (microorganisms) decay / decompose / digest / breakdown / rot

ignore eat

• (breakdown) releases minerals / nutrients / ions / salts / named

ignore food

• (microorganisms) respiration

ignore other organisms respiring

• (microorganisms / respiration) release of carbon dioxide 3

[8]




Page 6

M5. (a) (i) 1 hour 15 mins / 1.25 hours / 75 mins

allow 1:15

ignore 1.15 hours 1

(ii) increase in (core / body) temperature

ignore numbers 1

(due to an) increase in respiration or more muscle contraction 1

releasing energy (as a waste product)

allow produces ‘heat’ do not allow making energy

1

skin temperature decreases 1

(because there is) sweating 1

(which) evaporates and cools the skin

ignore references to vasodilation or vasoconstriction 1

(iii) (there is) dilation of vessels (supplying skin capillaries)

allow vasodilation

allow blood vessels widen

ignore expand

do not accept dilating capillaries or moving vessels 1

(so) more blood flows (near skin) (surface) or blood is closer (to the skin)

ignore ref to heat 1

(c) pancreas detects (low) blood glucose 1

produces glucagon




Page 7

do not allow glucagon made in the liver 1

(so) glycogen is converted to glucose

allow adrenaline released which increases conversion of glycogen to glucose

or

reduced insulin production so less glucose into cells / less glucose converted to glycogen

for 1 mark 1

[12]




Page 8

M6.(a) if body temperature too high blood vessels supplying skin (capillaries) dilate / widen

do not accept capillaries / veins dilate/constrict 1

if body temperature is too low blood vessels supplying skin (capillaries) constrict / narrow

do not accept idea of blood vessels moving (through skin) 1

ignore expand

accept arteries / arterioles for ‘blood vessels’ if no reference to skin allow blood vessels dilate and blood vessels constrict for one mark

so more / less blood flows through skin (capillaries) or nearer the surface of the skin

must correctly relate to dilation or constriction 1

so more / less heat is lost (from the skin by radiation)


(b) sweat released 1

cannot evaporate because of high humidity / all the water vapour in the air 1

so less heat lost / less cooling

or

it is evaporation of sweat that cools the body 1

[7]




Page 9

M7.(a) Pancreas


(b) any three from:

max 2 if any one process goes on in wrong organ

• (amino acids) broken down

• (amino acids) form urea

• (amino acids broken down / converted or urea formed) in liver

• (urea / broken down amino acids) removed / filtered by kidney

do not allow amino acids filtered / removed by kidney

• (urine / urea / broken down amino acids) stored / held in bladder

do not allow amino acids stored / held in bladder 3

[4]




Page 10

M8. (a) (i) A 1

(ii) (protein) molecule is large

ignore letters 1

cannot pass through filter

(protein is) too big to get through the filter = 2 marks 1

(b) B is taken back into the blood or

B is reabsorbed 1

reabsorbed completely

or reabsorbed after filtration 1

(c) RBC is too big to pass through filter 1

Haemoglobin is inside red blood cells or haemoglobin released when RBC bursts

1

Haemoglobin is small enough to pass through filter

or haemoglobin diameter 1

[8]




Page 1

Human nervous system

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA


Sub-Topic Human nervous system


Booklet Mark scheme 1


Score: /54

Percentage: /100




Page 2

M1. (a) any two from: • drop the ruler from the same height • use the same / dominant hand each time • thumb same distance from ruler at the start • use same type / weight of ruler • drop the ruler without any force each time • keep arm resting on the edge of the table

2

(b) 8

allow 8.0 1

(c) 2 (in test number 2) 1

(d) 12 1

(e) (12 + 13 + 13 + 9 + 8 / 5 =) 11 1

(f) 0.15 − 0.12 (s) 1

0.03 (s)

allow 0.03 (s) with no working shown for 2 marks 1

(g) carry out more repeats 1




Page 3

(h) caffeine speeds up reflex actions or reduces reaction time

1

[10]




Page 4

M2. (a) A sperm 1

B egg 1

C fertilised egg 1

D embryo 1

(b) insert into mother

ignore fertilise / check fertilisation / check viability 1

womb / uterus 1

(c) (i) one quarter 1

(ii) no / little chance of success over 42 1

reference to table of only two women in the age bracket 40-42 years became pregnant

the statement ‘only 2 out of 53 40-42 year old women became pregnant / had babies’ gains 2 marks

1

(iii) so fewer twins / multiple birthsormultiple births more dangerous




Page 5

1

[10]

M3. (a) (i) skin 1

(ii) kidneys

accept kidney 1

(iii) lungs

accept lung 1

(b) (i) multiply temperature by number of students at that temperature and add them up

allow (36.8 5) + (36.9 3) + (37.0 6) + (37.1 7) + (37.2 3)

allow 888 1

divide by number of students

allow divide by 24 1

(ii) 10 / ten 1

(iii) so enzymes work (well)

ignore death / overheating / hypothermia

allow body reactions work (well) 1

[7]




Page 6

M4.(a) brain


blood 1

sweat 1

(b) (i) A 1


accept salts


(iii) any one from:


1

[6]




Page 7

M5.(a) sensory neurone 1

(b) (i) synapse 1

(ii) a chemical 1

(c) (What happens to the muscle)

mark both parts of the question together

any one from:

• contraction / contracts

ignore relaxation / relaxes / tenses 1

• gets shorter

(How this helps the body)

idea of protection for body (from damage / pain)

eg moves finger / arm away (from pin / stimulus / source of pain)

1

[5]




Page 8

M6. (a) (i) stimulus 1

(ii) cytoplasm 1

(b) (i) ear(s)

in this order only 1

eye(s)

accept retina 1

skin

ignore extra detail 1

(ii) A muscle 1

[6]




Page 9

M7.(a) (i) sensory neurone 1

a synapse 1

(ii) contract 1

(iii) not connected to brain / coordinated only by spinal cord 1

(iv) automatic / rapid (response)

allow no thinking / faster / less time 1

protects body from danger / from damage / from burning 1

(b) (i) caffeine decreases reaction time

accept caffeine speeds up / quicker reactions 1

(ii) the two sets of results overlap (considerably)

allow use of appropriate numbers – eg 5 of the ‘after’ results overlap with the ‘before’ results

allow ‘wide spread of results’ allow ‘it was just one person’ or ‘it was a small sample’ accept use of one pair of results only – if meaning is clear

accept use of one pair of overlapping results 1

(iii) any two sensible suggestions: eg

• more repetitions • perform investigation on several other people • use other (measured) amounts of coffee • use different / more time intervals




Page 10

• other suggested measure of reaction time – eg computer-generated light flash + time measurement

• use pure caffeine or caffeine tablets 2

[10]


Save My Exams! – The Home of Revision For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/

Page 1

Human nervous System

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA


Sub-Topic Human nervous system




Score: /59

Percentage: /100


Page 2

M1.(a) (i) cerebral cortex

accept cerebrum / cerebral hemisphere 1

(ii) MRI (scan)

allow CAT / CT scan do not accept MIR

or

electrode stimulation

allow electrical stimulation 1

(b) (i) sharp point stimulates (pain) receptor (in the skin)

must be in correct order 1

to send (nerve) impulse

ignore information and messages 1

via sensory neurone 1

to spinal cord

do not accept spine, ignore CNS 1

crosses synapse

allow synapse in any correct context 1

to other (relay) neurones / to brain

do not accept motor neurone

allow explanation in a flow diagram 1

(ii) damage must be between arms and legs / below arms

accept below the waist 1


Page 3

since information from nerves in arms still reaches the brain / information from the legs doesn’t reach the brain

1

[10]


Page 4

M2. (a) Y - spinal cord / central nervous system / CNS

do not accept spine

ignore nerve / nervous system / coordinator

ignore grey / white matter 1

W - receptor / nerve ending

ignore sensory / neurone / stimulus 1

X - effector / muscle

allow gland 1

(b) any two from: eg

accept reverse argument for each marking point

• reflex action quicker

• effect of reflex action over shorter period

• hormone involves blood system and reflex involves neurones / nerve cells

ignore nervous system / nerves

• reflex involves impulses and hormone involves chemicals

• reflex action affects only one part of the body

ignore involves brain

ignore outside / inside stimuli 2

[5]


Page 5

M3. (a) any three from:

• streamlined shape enables it to swim quickly (to catch fish) • wings (provide power) to move quickly (to catch fish)

allow ‘flippers’ • wings used for steering • white underside / dark top acts as camouflage (so prey less likely to see it) • long / sharp beak to catch fish

3

(b) any three from:

• reduces (total) surface area of penguins exposed to wind / cold atmosphere • reduced number of penguins exposed (to wind / cold)

accept reference to movement in or out of the huddle

accept outer ones insulate / act as barrier • reducing heat loss

allow reduced cooling • ‘share’ body warmth / heat

3

(c) (i) any two from:

• size of tubes • volume of (hot) water

accept amount of (hot) water • left for same length of time

allow measured at same time intervals • starting temperature

2

(ii) any two from:

• tube alone (C) lost heat most (rapidly) • tube B intermediate • tube A least (rapidly)

allow correct use of figures for all 3 tubes

ignore just quoting final temperature 2

(iii) confirms suggestion

no mark awarded


Page 6

accept correct answers referring to other suggestions in (b)

since (both outer and inner) tubes in bundle lost heat less rapidly (than ‘stand − alone’ tube)

comparison needed 1

penguins in a huddle lose less heat (than single ones)

accept ‘it is the same for penguins’ 1

(d) if the core body temperature is too high

blood vessels supplying the skin (capillaries) dilate / widen

accept reference to arteries / arterioles but not veins / capillaries

do not accept references to movement of blood vessels

ignore enlarge / expand

reference to skin / surface required only once 1

so that more blood flows through the (capillaries) in skin / near surface

reference to ‘more’ needed at least once to gain 2 marks 1

and more heat is lost

reference to ‘more’ needed at least once to gain 2 marks 1

if the core body temperature is too low

blood vessels supplying the skin (capillaries) constrict / narrow

allow full marks if ‘too low’ given first

if no other marks awarded, allow vasodilation when too warm and vasoconstriction when too cold for 1 mark

1

(e) (i) wings move to provide movement for diving

allow muscles contract / work 1

energy (for movement) comes from respiration

do not allow produces / makes / creates energy allow energy comes from / is supplied by / is released by respiration

1

respiration / muscle contraction also releases heat

allow produces heat 1


Page 7

(ii) any three from:

• feet not / less used or no muscle contraction in feet

allow little energy / heat released through respiration in feet

do not allow veins / capillaries • vessels supplying feet constrict / less blood to feet • so temperature in feet cools / decreases • more heat loss from large surface area or rapid flow of cold water over

foot 3

[22]


Page 8

M4. (a) tissue → organ → organ system

one right for 1 mark

three right for 2 marks 2

(b) Epithelial tissue → covers the outside and the inside of the stomach

more than one line from a tissue = no mark 1

Glandular tissue → produces digestive juices 1

Muscular tissue → allows food to be churned around the stomach 1

(c) (i) light

ignore dark 1

(ii) moving (to the dark) 1

(iii) any two from:

• use more woodlice • repeat the experiment • run for a longer time

2

[9]


Page 9

M5. (a) detect changes in surroundings or detect stimuli

allow any named stimulus for skin 1

convert information to impulse

allow send impulse to sensory neurones / brain 1

(b) (i)

muscle contract(ion)

gland release / secrete / produce chemical / hormone / enzyme

1 mark for each effector

1 mark for each response

response must match type of effector (if given)

ignore examples

ignore relax(ation) / movement for contraction

do not allow expansion for muscles 4

(ii) any one from:

• (maintain temperature at which) enzymes work best • so chemical reactions are fast(est) • prevent damage to cells / enzymes

allow prevent enzymes being denatured (by temperature being too high)

1

[7]


Page 10

M6.Marks awarded for this answer will be determined by the Quality of Communication (QC) as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.

0 marks No relevant content.

Level 1 (1 – 2 marks) There is a description of thermoregulation or at least one correct mechanism (skin,

sweat glands or muscles) but roles may be confused.

Level 2 (3 – 4 marks) There is a description of thermoregulation or some correct mechanisms (sweating,

shivering, blood flow in the skin).

Level 3 (5 – 6 marks) There is a clear description of thermoregulation by TC or skin and some correct

control mechanisms.


full marks may be awarded for detailed description of what happens if the core temperature is either too high or too low

• temperature receptors in TC • the TC detects (core) body / blood temperature • temperature receptors in the skin send impulses to the TC, giving information

about skin temperature • if the core body temperature is too high: blood vessels / arterioles supplying

the skin capillaries dilate / vasodilation

do not accept refs to veins instead of arterioles or answers that imply blood vessels have moved up / down through the skin.

• so that more blood flows (through the skin) and more heat is lost • sweat glands release more sweat to cool the body • by evaporation • if the core body temperature is too low: blood vessels supplying the skin

capillaries constrict • to reduce the flow of blood (through the skin) and less heat is lost

allow idea of blood diverted to vital organs in extreme cold • muscles may shiver to release (heat) energy • from respiration, some of which is lost as heat

[6]



Page 1

Human nervous system

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA






Score: /54

Percentage: /100




Page 2

M1. (a) pupils dilated (at B)

allow converse for A

1

in dim light / low light levels 1

because circular muscles (in iris) relax 1

(and) radial muscles contract 1

(b) figure 2 shows myopia where light does not focus on the retina

allow refraction 1

in figure 3 the lens bends the light so that light focuses on the retina 1

[6]




Page 3

M2. (a) if body temperature too high blood vessels supplying skin (capillaries) dilate / widen

do not accept capillaries / veins dilate/constrict 1

if body temperature is too low blood vessels supplying skin (capillaries) constrict / narrow

do not accept idea of blood vessels moving (through skin) 1

ignore expand

accept arteries / arterioles for ‘blood vessels’ if no reference to skin allow blood vessels dilate and blood vessels constrict for one mark

so more / less blood flows through skin (capillaries) or nearer the surface of the skin


so more / less heat is lost (from the skin by radiation)


(b) sweat released 1

cannot evaporate because of high humidity / all the water vapour in the air 1

so less heat lost / less cooling

or

it is evaporation of sweat that cools the body 1

[7]




Page 4

M3. (a) A cytoplasm

in this order only 1

B (cell) membrane

do not accept (cell) wall 1

(b) (i) synapse 1

(ii) (as) chemical

accept neurotransmitter or named

ignore references to how the chemical is passed

do not accept electrical 1

(c) (from light-sensitive cell to connecting neurone) to sensory neurone

ignore references to synapses accept ‘nerve cell’ for neuron(e) throughout penalise ‘nerve’ for neurone once only

1

(sensory neurone) to brain / CNS

allow (sensory neurone) to relay neurone / spinal cord 1

(brain / CNS) to motor neurone

allow (relay neurone / spinal cord) to motor neurone 1

(motor neurone) to (eyelid) muscle

ignore effector 1

[8]




Page 5

M4. (a) A sensory (neurone)

ignore nerve 1

B motor (neurone)

ignore nerve 1

C spinal cord / central nervous system / white matter

accept grey matter 1

(b) by chemical / substance

allow transmitter 1

(c) muscle

allow extensor

ignore muscle names 1

[5]




Page 6

M5. (a) motor

allow efferent / postsynaptic

allow another relay (neurone) 1

(b) release of chemical (from relay neurone)

allow ecf for ‘motor’ neurone from (a) allow release of neurotransmitter / named example

1

chemical crosses gap / junction / synapse

allow diffuses across

allow chemical moves to X 1

chemical attaches to X / motor / next neurone (causing impulse) 1

(c) (curare) decrease / no contraction

accept (muscle) relaxes 1

(strychnine) increase / more contraction

if no other mark awarded allow 1 mark for (curare) decrease / no response and (strychnine) increase / more response

1

[6]




Page 7


allow 1:15

ignore 1.15 hours 1


ignore numbers 1




1






allow vasodilation


ignore expand





produces glucagon





Page 8



or


for 1 mark 1

[12]




Page 9

M7. (a) any two from: • drop the ruler from the same height each time • let the ruler drop without using any force • same type / weight of ruler • thumb should be same distance from the ruler each time at the start • use the same hand to catch the ruler each time • carry out the experiment with the lower arm resting in the same way on the

table

allow description of holding bottom edge of ruler opposite the catcher’s thumb

2

(b) 117 1

(c) 1

0.1539

allow 01539 with no working shown for 2 marks 1

0.154

allow 0.154 with no working shown for 3 marks 1

allow ecf as appropriate

(d) no indication beforehand when the colour will change or you might be able to tell when the person is about to drop the ruler

1

measurement of time is more precise (than reading from a ruler) or

resolution (of computer timer) is higher 1




Page 10

(e) cerebral cortex

allow cerebrum 1

ignore identified lobes

(f) cerebellum 1

[10]




Page 1

Hormonal Coordination in Humans

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA


Sub-Topic Hormonal Coordination in Humans




Score: /57

Percentage: /100




Page 2

M1. (a) liver 1

(b) insulin

do not accept glucagon 1

(c) kidney 1

(d) to replace water / ions / salt 1

(that is) lost in sweat 1

[5]




Page 3

M2. (a) (i) kidney 1

(ii) bladder 1

(iii) liver 1

(iv) lung(s) 1

(v) skin 1

(b) (i) 3000

allow 2970 to 3030

correct answer gains 2 marks with or without working

if answer incorrect allow 1 mark for evidence of 1550 + 450 + 1000 (allow tolerance of + or – ½ square on each)

2

(ii) 1600

allow 1570 to 1630 1

(iii) 1400

allow (b)(i) – (b)(ii) 1

(iv) correct plot from (b)(iii)

tolerance ½ square ignore width 1




Page 4

(v) cells swell / overhydrated / damaged

accept poisoned (by urea) 1

[11]




Page 5

M3. (a) (i) water 1

(ii) small 1

(iii) 3.15 1

(b) (i) 21 000 1

(ii) 2 years 1

(iii) prevent rejection 1

[6]




Page 6

M4. (a) pancreas


(b) (i) protein


(ii) any one from:

• (controlling / changing) diet

accept sugar(y foods) / named eg

ignore references to starch / fat / protein / fibre

• exercise

accept example, eg go for a run

• pancreas transplant

accept named drug eg metformin 1

(c) (i) increase

ignore reference to women 1

then fall 1

relevant data quote (for male)

eg max at ages 65–74 or starts at 10 (per thousand) or max at 130 (per thousand) or ends at 120 (per thousand)

accept a difference between any pairs of numbers in data set

accept quotes from scale eg ‘130’ or ’130 per thousand’ but not ’130 thousand’; to within accuracy of +/- 2 (per thousand)

1

(ii) (between 0 and 64) more females (than males) or less males (than females)




Page 7

ignore numbers

allow eg females more diabetic than males 1

(over 65) more males (than females) or less females (than males)

allow eg males more diabetic than females 1

[8]




Page 8

M5. (a) (i) skin 1

(ii) kidneys

accept kidney 1

(iii) lungs

accept lung 1

(b) (i) multiply temperature by number of students at that temperature and add them up

allow (36.8 5) + (36.9 3) + (37.0 6) + (37.1 7) + (37.2 3)

allow 888 1

divide by number of students

allow divide by 24 1

(ii) 10 / ten 1

(iii) so enzymes work (well)

ignore death / overheating / hypothermia

allow body reactions work (well) 1

[7]




Page 9

M6.(a) brain


blood 1

sweat 1

(b) (i) A 1


accept salts


(iii) any one from:


1

[6]




Page 10

M7. (a) (i) B 1

(ii) D 1

(iii) C 1

(b) (i) insulin 1

(ii) pancreas 1

[5]




Page 11

M8. (a) A – pituitary 1

B – adrenal 1

(b) ovary 1

(c) diaphragm


(d) condom 1

(e) Level 2 (3–4 marks): A detailed and coherent evaluation is provided which considers a range of advantages and disadvantages and comes to a conclusion consistent with the reasoning.

Level 1 (1–2 marks): An attempt to describe the advantages and disadvantages is made, which may not come to a conclusion. The logic may be inconsistent at times.

0 marks: No relevant content.

Indicative content

advantages of the plastic IUD: • is effective for longer than the copper IUD • does not need to be replaced as often as the copper IUD • although the pain of periods are more severe, the pain with the copper IUD is

likely to be worse

• can reduce the bleeding during a period • most of the possible side effects are not serious, eg feeling sick, acne and

headaches.

disadvantages of the plastic IUD: • needs to be implanted for a period of time before it is effective ie not




Page 12

emergency contraception • can make the pain of period more severe • can cause more side effects than the copper IUD • can cause some more severe side effects such as cysts on the ovaries

an understanding that the side effects are only possible and may not necessarily occur

additional examiner guidance: • pupils should add value to the points in the table and should not just be copies

verbatim • credit can also be given for other correct advantages and disadvantages from

the candidates’ own knowledge and understanding • allow converse points if clearly made

4

[9]




Page 1

Hormonal coordination in humans

Mark Scheme 1

Level GCSE (9-1)

Subject Biology Exam Board AQA


Sub-Topic Hormonal coordination in humans




Score: /57

Percentage: /100



Page 2

M1. (a) B 1

less / no insulin (produced) or insulin produced in pancreas

allow pancreas can’t monitor (blood) sugar (level)

ignore pancreas can’t control (blood) sugar (level)

allow increased glucagon production

allow A as liver stores less glucose / sugar for 2 marks only 1

(b) (i) (it / protein / insulin) digested / broken down

if ref to specific enzyme must be correct (protease / pepsin)

ignore denatured

do not accept digested in mouth / other incorrect organs 1

(ii) any two from:

ignore injections

• (attention to) diet

accept examples, eg eat less sugar(y food) or eat small regular meals

allow eat less carbohydrate / control diet

ignore cholesterol or balanced / healthy diet

• exercise

ignore keep fit / healthy

• (pancreas) transplant / stem cells / genetic engineering 2

[5]



Page 3

M2. (a) person with muscle disease:

allow reverse argument for healthy person

any three from:

NB all points are comparative except peak (point 3)

allow use of two approximate figures as a comparison

• higher resting rate or higher at start

• when exercise starts / then increases more / more rapidly

accept description eg rise …. fall

• peaks (then falls)

• levels off later than healthy person

• higher rate during exercise

if no other marks awarded allow 1 mark for ‘it’s higher’

• greater range 3

(b) (i) oxygen

accept adrenaline

accept O2

do not accept O, O2 or O2

1

(ii) cannot release sugar / glucose (from glycogen)

or

cannot store glucose / sugar (as glycogen) 1

need to receive glucose / sugar (from elsewhere)

ignore oxygen 1

for energy / respiration / cannot store energy



Page 4

ignore aerobic / anaerobic 1

[7]



Page 5

M3. (a) (i) chemical 1

(ii) pituitary gland 1

(b) 8

allow 9 or 10 1

(c) (i) any four from: • progesterone starts being produced at 4 weeks / no progesterone

before 4 weeks • and then / from 4 weeks increases • oestrogen at constant / low level (from 0) to 20 weeks • and then / from 20 weeks increases • from 20 − 36 weeks level of O rises more steeply than that of P or • P is always higher than 0 from 6 to 36 weeks

if no other marks awarded, allow progesterone and oestrogen both increase / rise for 1 mark.

4

(ii) oxytocin 1

level of oxytocin increases just before birth 1

[9]



Page 6

M4. (a) (i) rate of chemical reactions (in the body) 1

(ii) any two from:

• heredity / inheritance / genetics

• proportion of muscle to fat or (body) mass

allow (body) weight / BMI

• age / growth rate

• gender

accept hormone balance or environmental temperature

ignore exercise / activity 2

(b) (i) 77

correct answer with or without working gains 2 marks

allow 1 mark for 70 / 56 or 1.25 or 5 2

(ii) increase exercise

accept a way of increasing exercise 1

reduce food intake

accept examples such as eat less fat / sugar

allow go on a diet or take in fewer calories

ignore lose weight

ignore medical treatments such as gastric band / liposuction 1

[7]



Page 7

M5. (a) (i) any one from:

• chemical messenger / message

allow substance / material which is a messenger

• chemical / substance produced by a gland

allow material produced by a gland

• chemical / substance transported to / acting on a target organ

• chemical / substance that controls body functions 1

(ii) gland / named endocrine gland

brain alone is insufficient


(iii) in blood / plasma or circulatory system or bloodstream

accept blood vessels / named

do not accept blood cells / named 1

(b) each hormone must be linked to correct actionapply list principleignore the gland producing hormone

FSH stimulates oestrogen (production) / egg maturation / egg ripening

ignore production / development of egg 1

oestrogen inhibits FSH

allow oestrogen stimulates LH / build up of uterine lining 1

LH stimulates egg / ovum release / ovulation

accept LH inhibits oestrogen accept LH controls / stimulates growth of corpus luteum ignore production of egg

1



Page 8

[6]

M6. (a) (i) A – pituitary

allow hypothalamus 1

B – ovary / ovaries 1

(ii) in blood (stream)

accept in plasma

ignore dissolved 1

(b) (i) FSH and Luteinising Hormone (LH) 1

(ii) fertilised OR reference to sperm

1

form embryos / ball of cells or cell division 1

(embryo) inserted into mother’s womb / uterus

allow (fertilised egg) is inserted into mother’s womb / uterus 1

(iii) any one from:

• multiple births lead to low birth weight

• multiple births cause possible harm to mother / fetus / embryo /



Page 9

baby / miscarriages

allow premature

ignore reference to cost / ethics / population 1

(c) (i) any one from:

• almost identical

allow S (slightly) more successful

• both approximately 20% 1

(ii) larger numbers (in clinic R) (in 2007)

allow only 98 (in S) (compared to 1004 (in R)) 1

results likely to be more repeatable (in 2008)

allow more reliable

do not accept more reproducible / accurate / precise 1

[11]



Page 10

M7. (a) (i) 3.0

accept 3 1

(ii) any two from:

• take in water • take in ions / minerals / nutrients

accept salts / named ions

ignore food • anchorage / support

2

(iii) asexual reproduction 1

(b) (i) a tropism 1

(ii) if tip exposed / A – grows / bends towards light

allow tip of A moves towards light

ignore A responds to light

allow remained ‘straight’ 1

if tip covered / B – did not grow towards light / remained vertical

ignore B does not respond to light

ignore phototropism

only A grows towards the light = 2 marks 1

(c) (i) auxin 1

(ii) hormone comes from the tip 1



Page 11

more on shady side / moves away from light

allow reference to right-hand side 1

stimulates growth 1

more growth on shady side (than on light side)

answer must be comparative

ignore phototropism

ignore cell division 1

[12]



Page 1

Hormonal Coordination in Humans

Mark Scheme 1

Level GCSE (9-1)

Subject Biology

Exam Board AQA


Sub-Topic Hormonal Coordination in humans




Score: /57

Percentage: /100




Page 2

M1. (a) if too high insulin released from pancreas 1

so glucose is moved into cells

allow glucose is stored 1

if too low, glucagon is released (from pancreas) 1

causes glycogen to be converted to glucose and released into the blood 1

(b) type 1 not enough / no insulin produced 1

whereas type 2 cells do not respond to insulin 1

type 1 is treated with injections of insulin 1

whereas type 2 is treated with diet and exercise or loss of weight or drugs

1

(c) (3.45 × 106) + (5.49 × 105) = 3.999 × 106

or 3 450 000 + 549 000 = 3 999 000

allow 3.999 × 106 or 3 999 000 with no working shown for 1 mark

1




Page 3

or

= 6.15

allow 6.15 with no working shown for 2 marks

allow for 1 mark for a calculation using either:

or

or

or

1

6.2

allow 6.2 with no working shown for 3 marks 1

allow ecf from second step correctly rounded for 1 mark

(d) could be other reasons for glucose in urine or blood test gives current / immediate result, urine levels might be several hours old or not always glucose in urine

1

(e) results not affected by glucose from food or 8 hours is sufficient time for insulin to have acted on any glucose from food eaten




Page 4

or so that there is a low starting point to show the effect

1

(f) (patient A)

no mark for identifying A

glucose level much higher (than B) 1

and remains high / does not fall 1

[15]




Page 5

M2. (a) Pancreas


(b) any three from:

max 2 if any one process goes on in wrong organ

• (amino acids) broken down

• (amino acids) form urea

• (amino acids broken down / converted or urea formed) in liver

• (urea / broken down amino acids) removed / filtered by kidney

do not allow amino acids filtered / removed by kidney

• (urine / urea / broken down amino acids) stored / held in bladder

do not allow amino acids stored / held in bladder 3

[4]




Page 6


allow 1:15

ignore 1.15 hours 1


ignore numbers 1




1






allow vasodilation


ignore expand





produces glucagon





Page 7



or


for 1 mark 1

[12]




Page 8

M4.Marks awarded for this answer will be determined by the Quality of Communication (QC) as well as the standard of the scientific response. Examiners should also refer to the information on page 5, and apply a ‘best-fit’ approach to the marking.

0 marks No relevant content.

Level 1 (1 – 2 marks) There is a brief description of kidney function including a mention of pituitary gland or hormones but roles may be confused.

Level 2 (3 – 4 marks) There is a clear description of kidney function in relation to fluctuations in blood water levels and the roles of the pituitary gland or hormone is mentioned with correct role.

Level 3 (5 – 6 marks) There is a clear and detailed scientific description of kidney function in relation to fluctuations in blood water levels and of the roles of the pituitary gland and ADH.


• if water content too low, ADH released • from pituitary gland • into the blood • (causing) kidney reabsorbs more water • more concentrated / small volume urine produced • if water content too high, ADH lowered / not produced • less water reabsorbed by kidney • more dilute / larger volume urine produced

full marks may be awarded for detailed description of either water loss or gain

[6]




Page 9

M5. (a) (the kidney) filters the blood

ignore refs to hormones and drugs 1

(and then) reabsorbs all of the glucose 1

reabsorbs some of the ions

allow salts

ignore minerals 1

reabsorbs some of the water 1

releases urea (in urine) 1

(b) (i) should fall from 28 (to the end of dialysis)

ignore any line drawn after end of dialysis

allow + / - 0.5 square graph line must fall to / below below 15

1

(ii) should stay level at about 6 throughout

ignore slight variations allow + / - 1 square

ignore any line drawn after end of dialysis 1

(c) (i) immune system

allow white blood cells / lymphocytes 1

(produces) antibodies 1

(which) attack the antigens (on the transplanted kidney)

non-matching antigens insufficient 1

(ii) any one from: • tissue typing (to find match) • treating with drugs that suppress the immune system

accept treat with immunosuppressants. 1

[11]




Page 10

M6. (a) Too much thyroxine is released into the blood 1

which raises BMR 1

causing increase in formation of glycogen / lipids / proteins or increase in rate of respiration or increase in breakdown of excess proteins

1

(b) FSH causes eggs to mature and stimulate ovaries to produce oestrogen 1

LH stimulates the egg to be released 1

(c) (missing a dose causes a) dip / drop in progesterone levels 1

(therefore) FSH is not inhibited anymore 1

(therefore) LH is not inhibited anymore 1

(and consequently) an egg is matured and released

allow (and consequently) an egg is available to be fertilised 1

[9]


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