edexcel biology a2 june 2009 ms
TRANSCRIPT
Mark Scheme Summer 2009
GCE
GCE Biology (8040/9040 & 8042/9042)
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ii 0906 8040/9040, 8042/9042
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Summer 2009
Publications Code UA021146
All the material in this publication is copyright © Edexcel Ltd 2009
iii 0906 8040/9040, 8042/9042
Contents
General Introduction iv
Unit Codes and Unit Titles v
General Information vi
Mark Schemes
Unit 1 6101 Molecules and cells 1
Unit 2B
Unit 2H
6102
6112
Exchange, transport and reproduction
Exchange, transport and reproduction in humans
12
21
Unit 3 6103/02*
6103/03
Written alternative to coursework*
Energy and the environment
31
35
Unit 4 Core material
Option A
Option B
Option C
Respiration and coordination
Microbiology and biotechnology
Food science
Human health and fitness
40
47
52
58
Unit 5B
Unit 5H
6105
6115
Genetics, evolution and biodiversity
Genetics, human evolution and biodiversity
63
75
Unit 6 6106/02
6106/03
Written alternative to coursework
Synoptic Paper
86
92
iv 0906 8040/9040, 8042/9042
GENERAL INTRODUCTION Mark schemes are prepared by the Principal Examiners and revised, together with the relevant questions, by a panel of senior examiners and subject teachers. The schemes are further amended at the Standardisation meetings attended by all examiners. The Standardisation meeting ensures as far as possible that the mark scheme covers the candidates' actual responses to questions and that every examiner understands and applies it in the same way. The schemes in this document are the final mark schemes used by the examiners in this examination and include the amendments made at the meeting. They do not include any details of the discussions that took place in the meeting, nor do they include all of the possible alternative answers or equivalent statements that were considered to be worthy of credit. It is emphasised that these mark schemes are working documents that apply to these papers in this examination. Every effort is made to ensure a consistent approach to marking from one examination to another but each marking point has to be judged in the context of the candidates' responses and in relation to the other questions in the paper. It should not be assumed that future mark schemes will adopt exactly the same marking points as this one. Edexcel cannot under any circumstances discuss or comment informally on the marking of individual scripts. Any enquiries about the marks awarded to individual candidates can be dealt with only through the official Enquiry about Results procedure.
v 0906 8040/9040, 8042/9042
Unit Codes and Unit Titles These Mark Schemes cover the units offered in this examination for Advanced Subsidiary Biology and Biology (Human) (8040 and 8042) and Advanced Biology and Biology (Human) (9040 and 9042). The units available in this examination series for the complete qualifications are listed in the table below.
Level Unit Biology Biology (Human)
1 6101 Molecules and cells 6101
2 6102 Exchange, transport and reproduction
Exchange, transport and reproduction in humans 6112
AS
3 6103 Energy and the environment and Practical Assessment 6103
4 6104 Respiration and coordination and Options 6104
5 6105 Genetics, evolution and biodiversity
Genetics, human evolution and biodiversity 6115
A2
6 6106 Synoptic and Practical Assessment 6106
Cashing in The following tables show the units that must be taken in order to obtain an award for AS or Advanced GCE Biology, or for AS or Advanced GCE Biology (Human). Advanced Subsidiary Level Unit 8040 Biology 8042 Biology (Human)
AS 1 2 3
6101* 6102* 6103*
6101* 6112* 6103*
Advanced GCE Level Unit 9040 Biology 9042 Biology (Human)
AS 1 2 3
6101* 6102* 6103*
6101* 6112* 6103*
A2 4 5 6
6104#
6105#
6106#
6104#
6115#
6106#
* No longer available – final resit opportunity was June 2009 # Available for final time in January 2010.
vi 0906 8040/9040, 8042/9042
GENERAL INFORMATION The following symbols are used in the mark schemes for all questions:
Symbol Meaning of symbol
; semi colon Indicates the end of a marking point
eq Indicates that credit should be given for other correct alternatives to a word or statement, as discussed in the Standardisation meeting
/ oblique Words or phrases separated by an oblique are alternatives to each other
{} curly brackets Indicate the beginning and end of a list of alternatives (separated by obliques) where necessary to avoid confusion
() round brackets Words inside round brackets are to aid understanding of the marking point but are not required to award the point
[] square brackets Words inside square brackets are instructions or guidance for examiners
[CE] or [TE] Consecutive error / transferred error Crossed out work If a candidate has crossed out an answer and written new text, the crossed out work can be ignored. If the candidate has crossed out work but written no new text, the crossed out work for that question or part question should be marked, as far as it is possible to do so. Spelling and clarity In general, an error made in an early part of a question is penalised when it occurs but not subsequently. The candidate is penalised once only and can gain credit in later parts of the question by correct reasoning from the earlier incorrect answer. No marks are awarded specifically for quality of language in the written papers, except for the essays in the synoptic paper. Use of English is however taken into account as follows: •
•
•
the spelling of technical terms must be sufficiently correct for the answer to be unambiguous
e.g. for amylase, ‘ammalase’ is acceptable whereas ‘amylose’ is not e.g. for glycogen, ‘glicojen’ is acceptable whereas ‘glucagen’ is not e.g. for ileum, ‘illeum’ is acceptable whereas ‘ilium’ is not e.g. for mitosis, ‘mytosis’ is acceptable whereas ‘meitosis’ is not
candidates must make their meaning clear to the examiner to gain the mark.
a correct statement that is contradicted by an incorrect statement in the same part of an answer gains no mark – irrelevant material should be ignored.
Unit 1 (6101 /01) - Molecules and cells Question Number
Answer Mark
1
one mark for every two correct responses ;;;;
Feature Prokaryotic cell
Eukaryotic cell
nuclear envelope x
cell surface membrane
mitochondria x
Golgi apparatus x
(4)
1 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2
1. Benedict’s / Fehling’s ; 2. orange / red / brown / yellow / green ; 3. acid / named acid ; 4. alkali / named alkali ; 5. iodine (in KI) ;
(5)
2 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(a)
1. one glycerol, two fatty acids and one
phosphate group drawn ; 2. fatty acid(s) joining to glycerol with ester bond
/ ester bond joining fatty acid(s) to glycerol ;
3. one phosphate group joined to glycerol with ester bond ;
(3)
Question Number
Answer Mark
3(b)
{soluble / can dissolve} in water / eq ;
(1)
Question Number
Answer Mark
3(c)
1. form a (phospholipid) bilayer / eq ; 2. {phosphate / hydrophilic region} {interacts /
eq} with {aqueous environment / surroundings / cytoplasm} ;
3. {fatty acids / hydrophobic region } {restricts /
eq} movement of {charged / polar / water soluble molecules} {into cell / out of cell / eq} ;
max (2)
3 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(a)
A = starch grain ; B = granum ;
(2)
Question Number
Answer Mark
4(b)
1. correct measurement between X and Y ;
(from 99 to 104 mm) 2. correct division by 5 ; 3. correct magnification e.g. 19800 to 20800 ;
(3)
Question Number
Answer Mark
4(c)
palisade / guard / spongy / mesophyll ;
(1)
4 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(a)(i)
1. {root tip / shoot tip / meristematic tissue} /
eq ; 2. dividing cells are present / eq ;
(2)
Question Number
Answer Mark
5(a)(ii)
{acetic / acid} orcein / Feulgen’s / acetocarmine / Schiff’s reagent / lactoproprionic acid / toluidine blue / eq ;
(1)
Question Number
Answer Mark
5(a)(iii)
idea of getting {a single layer / eq} of cells ;
(1)
Question Number
Answer Mark
5(b)(i)
B D A C ;
(1)
Question Number
Answer Mark
5(b)(ii)
A = anaphase ; C = telophase ;
(2)
5 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(a)
1. reference to kinetic energy of molecules /eq ;
2. idea that molecules are moving randomly /
eq ;
3. idea that overall movement of molecules is down the concentration gradient ;
max (2)
Question Number
Answer Mark
6(b)
1. (at beginning) there is a concentration gradient
/eq ; 2. as concentration of A decreases on outside, it
increases on inside / eq ;
3. substance A moves from outside to inside ;
4. as concentration {gradient / difference} gets smaller, rate of change decreases ;
5. {no change in concentration / eq} when equal
on both sides / it reaches equilibrium ;
max (3)
6 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(c)(i)
1. active transport requires {energy / ATP} ;
2. active transport can move molecules against a
concentration gradient ;
3. active transport requires a protein (pump) ;
max (2)
Question Number
Answer Mark
6(c)(ii)
1. rate of change would be (almost) {linear /
constant / eq} ;
2. (changes) would occur faster /eq ;
3. idea that (overall) movement of molecules would not stop when concentrations equal e.g. equilibrium would not be reached, concentration inside would be greater than outside ;
max (2)
7 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)(i)
C A G U C A C G C ;;
(2)
Question Number
Answer Mark
7(a)(ii)
gln, ser, arg ;
(1)
Question Number
Answer Mark
7(a)(iii)
1. 21 (amino acids) ; 2. correct multiplication by 3 (to give 63) ;
(2)
Question Number
Answer Mark
7(b)(i)
1. contains {protein / enzymes} ; 2. and (r)RNA ;
3. reference to two subunits ;
4. reference to appropriate binding sites e.g. for
mRNA ;
max (2)
8 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(b)(ii)
1. ribosome {attaches/eq} to mRNA ; 2. two tRNA molecules (held in ribosome) /eq ;
3. (each) carrying a {specific/eq} amino acid /
eq ;
4. reference to anticodons on tRNA /eq ;
5. reference to complementary {bases / codon} on mRNA /eq ;
6. peptide bonds form between amino acids /eq ;
7. ribosome moves along mRNA /eq ;
8. correct reference to {start / stop} codons ;
max (5)
9 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(a)(i)
1. {protein / substrate} and enzyme {collide /
bind} / reference to enzymes-substrate complex being formed/ eq ;
2. peptide bonds {broken / eq} ;
3. {reference to / description of} hydrolysis ;
4. reference to formation of {smaller peptide
chains / amino acids} ;
max (3)
Question Number
Answer Mark
8(a)(ii)
idea that {smaller peptides / amino acids} dissolve whereas protein did not / eq ;
(1)
Question Number
Answer Mark
8(b)(i)
1. activity increases between pH 5 and 8 / eq ;
2. most active at pH 8 / eq ;
3. activity drops between pH 8 and 10 ;
4. correct manipulation of figures ;
max (2)
Question Number
Answer Mark
8(b)(ii)
1. pH is determined by {H+ concentration / eq} ;
2. reference to ionisation of {R groups / side
chains} ;
3. reference to {bonds / appropriate named bond} {breaking / eq} ;
4. reference to change in shape of active site ;
5. {substrate / protein} cannot bind to active site
/ eq ;
max (3)
10 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(c)
1. to keep the temperature (of the reaction)
constant ; 2. reference to {(45 °C) optimum temperature of
trypsin / fastest rate} ;
3. reference to a change in the temperature changes the rate of reaction e.g. idea that change in temperature {changes the kinetic energy of the molecules / changes the {number / energy / frequency} of the collisions};
max (2)
11 0906 8040/9040, 8042/9042
Unit 2B (6102/01) - Exchange, transport and reproduction Question Number
Answer Mark
1
1. Graafian / ovarian ; 2. luteinising hormone / LH ;
3. corpus luteum / yellow body ;
4. endometrium / lining of the uterus ;
(4)
12 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)
A sinoatrial node / sinuatrial node / SAN /
pacemaker ; B atrioventricular node / AVN ; C Purkyne fibres / Purkyne tissue / bundle of His ;
(3)
Question Number
Answer Mark
2(b)
. reference to more muscle ;
2. increased force of contraction / increased
3. left ventricle pumps blood round the whole
ax
1
pressure / eq ;
body / eq ;
m(2)
Question Number
Answer Mark
2(c)
. {oxygen / blood} supply to the heart muscle /
2. consists of coronary artery / coronary arteries ;
3. cardiac {vein / veins} / coronary
sinus ;
ax
1eq ;
capillaries /
m(2)
13 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(a)
1. {single layer of epithelium / simple ep
/ thin epithelium} to reduce diffusion dista/ eq ;
ithelium nce
sorbed on}
2. (presence of) microvilli to increase surface
area ;
3. (presence of) capillaries to transport abproducts / maintain {diffusion / concentratigradients ;
4. {lacteal / eq} for absorption of fats / eq ;
5. reference to carrier proteins explained ;
max (3)
Question Number
Answer Mark
3(b)(i)
1. {greater / faster / more steady / eq} uptake
when sodium ions are present ;
2. comparative, manipulated data comment – e.‘total uptake is 23 times higher in the presencof sodium ions’ or ‘684 µmol more taken up in presence of sodium ions’ ;
g. e
(2)
Question Number
Answer Mark
3(b)(ii)
1. reference to sodium-glucose cotransport / eq ;
2. membrane contains transporter proteins (for
3. without sodium, uptake is by (facilitated)
glucose and sodium) / eq ;
diffusion only / eq ;
max (2)
14 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(a)
. diaphragm contracts / eq ;
2. (and) moves downwards / flattens ;
3. external intercostal muscles contract ;
4. (and) raise the rib cage / pull ribs upwards /
5. reference to increase in volume of the thorax /
ax
1
pull ribs outwards ;
decrease in pressure ;
m(4)
Question Number
Answer Mark
4(b)
. consists of {flattened epithelial cells /
es} /
2. type II pneumocytes / surfactant-secreting
3. (alveolus is) surrounded with {connective tissue
4. (alveolus is) surrounded with capillaries / eq ;
5. edit correct reference to presence of
macrophages / eq ;
6. of basement membrane;
ax
1squamous epithelium / type I pneumocytthin epithelium / thin wall ;
cells / eq ;
/ collagen / elastic fibres} ;
cr
reference to presence
m(3)
15 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(c)(i)
concentration of carbon dioxide increases,
pulmonary ventilation increases / eq ;
t, y ventilation
of 26 dm min ;
ax )
1. as
2. reference to less change from 0% to 3% / greater change from 4% to 6% ;
3. credit manipulated, quantitative commen
e.g. overall increase in pulmonar3 -1
m(2
Question Number
Answer Mark
4(c)(ii)
ioxide / reduced pH / increased acidity}
stimulates the respiratory centre / eq ;
(1) {carbon d
16 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(a)
Mark as paired points i.e. adaptation ; function ;
1. presence of {haemoglobin / respiratory pigment} ;
2. with a high affinity for oxygen ;
3. presence of breathing tube / eq ;
4. to obtain oxygen from the air ;
5. presence of gills ;
6. to increase surface area (for gas exchange) ;
max (4)
Question Number
Answer Mark
5(b)
1. flattened body / streamlined shape / eq ;
2. to reduce resistance to water / eq ;
3. presence of hooks / claws / eq ;
4. to hold on to substrate / eq ;
(4)
17 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(a)
1. vessels / vessel elements ;
2. tracheids ;
3. presence of pits ;
4. fibres / sclerenchyma ;
5. lignified / eq ;
6. parenchyma / packing tissue ;
max (3)
Question Number
Answer Mark
6(b)(i)
1. stomata open ;
2. increase in {light intensity / temperature /
wind speed} / decrease in humidity ;
3. (therefore) transpiration rate increases ;
max (2)
Question Number
Answer Mark
6(b)(ii)
1. stomata close ;
2. decrease in {light intensity / temperature /
wind speed} / increase in humidity ;
3. (therefore) transpiration rate decreases ;
max (2)
18 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)
Pollination
1. {transfer / eq} of pollen (grains) ;
2. (from an anther) to a stigma / eq ; Protandry
3. stamen ripens / anthers mature / pollen released / eq ;
4. before carpels (mature) / eq ;
(4)
Question Number
Answer Mark
7(b)(i)
1. 90 – 45 or 45 ;
2. ÷ 6 ;
3. = 7.5 ;
(3)
Question Number
Answer Mark
7(b)(ii)
1. (with boron) pollen tubes grow faster / lo
/ eq ; nger
f
2. (with boron) keep growing / no levelling off
AND (without boron) stops growing / levels of/ eq ;
3. manipulated quantitative comparison, e.g. at
the end of experiment, pollen tubes are 3 times longer ;
max (2)
19 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(a)
Description Name of leucocyte
neutrophil /polymorph ;
monocyte ;
eosinophil / acidophil ;
(3)
Question Number
Answer Mark
8(b)(i)
1. reference to decrease in the affinity of
haemoglobin for oxygen ;
2. haemoglobin releases oxygen / eq ;
3. {at the same / at a given} partial pressure of oxygen / eq ;
4. idea that this makes oxygen available to
{cells / tissues / organs} ;
max (3)
Question Number
Answer Mark
8(b)(ii)
1. curve shifts to the right ;
2. oxygen released more readily / more oxygen
released / eq / idea that temperature increases in active tissues ;
(2)
20 0906 8040/9040, 8042/9042
Unit 2H (6112/01) - Exchange, transport and reproduction in humans
Question Number
Answer Mark
1
1. Graafian / ovarian ; 2. luteinising hormone / LH ;
3. corpus luteum / yellow body ;
4. endometrium / lining of the uterus ;
(4)
21 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)
A sinoatrial node / sinuatrial node / SAN /
pacemaker ; B atrioventricular node / AVN ; C Purkyne fibres / Purkyne tissue / bundle of His ;
(3)
Question Number
Answer Mark
2(b)
. reference to more muscle ;
2. increased force of contraction / increased
3. left ventricle pumps blood round the whole
ax
1
pressure / eq ;
body / eq ;
m(2)
Question Number
Answer Mark
2(c)
. {oxygen / blood} supply to the heart muscle /
2. consists of coronary artery / coronary arteries ;
3. cardiac {vein / veins} / coronary
sinus ;
ax
1eq ;
capillaries /
m(2)
22 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(a)
1. {single layer of epithelium / simple ep
/ thin epithelium} to reduce diffusion dista/ eq ;
ithelium nce
sorbed on}
2. (presence of) microvilli, to increase surface
area ;
3. (presence of) capillaries, to transport abproducts / maintain {diffusion / concentratigradients ;
4. {lacteal / eq} for absorption of fats / eq ;
5. reference to carrier proteins explained ;
max (3)
Question Number
Answer Mark
3(b)(i)
1. {greater / faster / more steady / eq} uptake
when sodium ions are present ; 2. comparative, manipulated data comment – e.
‘total uptake is 23 times higher in the presencof sodium ions’ or ‘684 µmol more taken up in presence of sodium ions ;
g. e
(2)
Question Number
Answer Mark
3(b)(ii)
1. reference to sodium-glucose cotransport / eq ;
2. membrane contains transporter proteins (for
3. without sodium, uptake is by (facilitated)
glucose and sodium) / eq ;
diffusion only / eq ;
max (2)
23 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(a)
1. diaphragm contracts / eq ;
2. (and) moves downwards / flattens ;
3. external intercostal muscles contract ;
4. (and) raise the rib cage / pull ribs upwards /
pull ribs outwards ;
5. reference to increase in volume of the thodecrease in pressure ;
rax /
max (4)
Question Number
Answer Mark
4(b)
1. consists of {flattened epithelial cells /
squamous epithelium / type I pneumocytes} / thin epithelium / thin wall ;
2. type II pneumocytes / surfactant-secreting
cells / eq ;
3. (alveolus is) surrounded with {connective tiss/ collagen / elastic fibres} ;
ue
5. credit correct reference to presence of
6. reference to presence of basement membrane;
4. (alveolus is) surrounded with capillaries / eq ;
macrophages / eq ;
max (3)
24 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(c)(i)
1. as concentration of carbon dioxide increases,
pulmonary ventilation increases / eq ;
2. / greater change from 4% to 6% ;
3. comment,
e.g. overall increase in pulmonary ventilation
ax )
reference to less change from 0% to 3%
credit manipulated, quantitative
of 26 dm3 min-1 ;
m(2
Question Number
Answer Mark
4(c)(ii)
{carbon dioxide / reduced pH / increased acidity}
imulates the respiratory centre / eq ;
) st
(1
25 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(a)
1. reference to damage to cartilage ; 2. reference to change in bone ;
3. in joints / knees / hips / spine / hands / feet ;
4. causes swelling / pain / reduced movements
(in joints) ;
max (3)
Question Number
Answer Mark
5(b)
1. in postmenopausal women / eq ;
2. {tablets / skin patches / eq} contain oe
(and progesterone) ; strogen
3. reference to use in preventing bone loss /
reducing the risk of fractures ;
4. due to loss of calcium / eq ;
max (3)
26 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(a)
Any two from:
1. air pressure ;
2. partial pressure of oxygen / pO2 ;
3. temperature ;
4. humidity ;
max (2)
Question Number
Answer Mark
6(b)(i)
1. reference to increase in birth weight as
atmospheric pressure increases ;
2. more effect 60 to 80 kPa / little difference 80to 100 kPa / levels out 80 or 87 or 93 to 100 kPa ;
g.
3. credit manipulated quantitative comment e.overall increase of 0.31 kg ;
(3)
Question Number
Answer Mark
6(b)(ii)
1. suggest that birth weight decreases as alt
increases ; itude
2. reference to greater effect at high altitude /
less effect at low altitude / eq ;
(2)
Question Number
Answer Mark
6(b)(iii)
lower pO2 at high altitude / reference to {hypoxia / eq }/ babies develop more slowly ;
(1)
27 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(b)(iv)
Any two from:
1. age of mother ;
2. nutrition / diet ;
3. genetic factors / eq ;
4. smoking ;
5. alcohol intake ;
max (2)
28 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)
1. sweat glands {secrete / eq} sweat ;
2. water in sweat evaporates / eq ;
3. evaporation has a cooling effect / eq ;
4. reference to latent heat ;
5. reference to change in rate of sweating in
relation to changes in body temperature ;
max (3)
Question Number
Answer Mark
7(b)(i)
1. calculation ;
2. 36.8 ;
(2)
Question Number
Answer Mark
7(b)(ii)
1. temperature higher (in the afternoon) ;
2. {exercise / activity} increases {metabolic rate
/ metabolism} ;
3. (which) generates heat / eq ;
(3)
29 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(a)
Description Name of leucocyte
neutrophil / polymorph ;
monocyte ;
eosinophil ;
(3)
Question Number
Answer Mark
8(b)(i)
1. reference to decrease in the affinity of
haemoglobin for oxygen ;
2. oxygen released more readily / more oxygen released / eq ;
3. {at the same / at a given} partial pressure of
oxygen / eq ;
4. idea that this makes oxygen available to (respiring) tissues ;
max (3)
Question Number
Answer Mark
8(b)(ii)
1. curve shifts to the right ; 2. oxygen released more readily / more oxygen
released / eq / idea that temperature increases in active tissues ;
max (2)
30 0906 8040/9040, 8042/9042
Unit 3 (6103/02) - Written Alternative to Coursework (International candidates ONLY)
Question Number
Answer Mark
1(a)
Mortality % Snail density
snails per 625 cm2
Juvenile Adult
10 10.0 15.0 20 0 37.5 35 8.6 48.6 50 7.0 58.0
neat table correctly formatted ; correct rows and columns with labels and units ; adult percentages correct ; juvenile percentages correct ;
(4)
Question Number
Answer Mark
1(b)
A axes correctly orientated & labelled scale correct ; F line graph format ; P all points correctly plotted ; L accurately drawn line passing through all points ;
(4)
31 0906 8040/9040, 8042/9042
Question Number
Answer Mark
1(c)
1. adult mortality increases with population
density eq ;
2. juvenile mortality not affected by population density ;
3. reference to large difference (51%) at highest
density / suitable manipulation of figures ;
4. all juveniles at 20 snails per 625 cm2 survive / eq ;
max (3)
Question Number
Answer Mark
1(d)
1. dead snails in cage may affect live snails ;
2. difficult to control environmental factors for
each cage ;
3. some adult snails may die off naturally / may have only short life span / may give birth / eq ;
4. difficult to {define ‘juvenile’ / determine age
of} snails ;
5. reference to effect on percentage mortality in low density (death of one snail causes large change in percentage) ;
max (3)
32 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)
1. control of growth medium - any TWO of same
soil/compost, same volume, same containers, seed sown at same density / eq ;
2. TWO named abiotic factors standardised for
growth e.g. light, temperature, water ;
3. standard sampling e.g. same mass / volume / use of cork borer ;
4. sampling at intervals of growth ;
5. {grind / homogenise / blend / eq} sample ;
6. filter extract ;
7. add {stated / same} volume of sucrase / add fixed volume of dilute HCl ;
8. incubate at fixed temperature (max 50 °C) {for fixed time / until equilibrated} / boil then neutralise ;
9. add {stated /same} volume of Benedict’s solution /use of test strip e.g. Diabur ;
10. reference to Benedict’s solution in excess / allow time for test strip colour to develop / eq ;
11. boil / heat above 60 °C for fixed time ;
12. filter dry and weigh precipitate / use of colorimeter / compare with colour chart ;
13. repeat at least 3 times in total ;
max (9)
33 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(b)
1. suitable table with raw data and units to
match method plan ;
2. reference to rate of production ;
3. line graph format / alternative matching plan ;
4. correct orientation and labelling of axes ;
max (3)
Question Number
Answer Mark
2(c)
Limitations 1. different regions of the root might contain
different concentrations of sucrose ;
2. presence of other reducing sugars in {either / both} varieties ;
3. mass of precipitate very small / precipitate can give inaccurate colorimeter readings / test strip colours difficult to match to standard ;
4. difficult to ensure that all sucrose is {broken down by sucrase / hydrolysed by HCl / eq} ;
Further work 5. conduct field trials of both varieties / test
both varieties in different climatic conditions ;
6. extract sucrose in normal way and check actual mass / measure sugar content at maturity / eq (if not in method);
7. more detailed analysis for other sugars present ;
max (6)
34 0906 8040/9040, 8042/9042
Unit 3 (6103/03) - Energy and the environment
Question Number
Answer Mark
1(a)(i)
suitable named ruminant e.g. cow / sheep / deer / moose ;
(1)
Question Number
Answer Mark
1(a)(ii)
1. reference to microorganisms / bacteria / eq ;
2. reference to cellulase / cellulose-digesting
enzyme / eq ;
3. into {sugars / monosaccharides / glucose / fatty acids / eq} ;
4. that can be absorbed / are soluble / eq ;
max (3)
Question Number
Answer Mark
1(b)(i)
cross in box under tooth A ;
(1)
Question Number
Answer Mark
1(b)(ii)
1. {side-to-side / rotational / circular / eq}
movement of jaw ;
2. sharp ridges on tooth ;
3. idea of interlocking of upper and lower molar teeth ;
4. reference to {grinding / eq} ;
5. {increase surface area / release cell contents /
break cell walls} for {digestion / enzyme action} ;
max (3)
35 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)(i)
((295 - 55) ÷ 295) x 100 ; 81.4 ;
(2)
Question Number
Answer Mark
2(a)(ii)
1. A, B and C more-or-less same / eq ;
2. D (significantly) less efficient than A, B & C /
eq ;
3. any other valid comparison ;
4. manipulated data to support any comparison ;
max (3)
Question Number
Answer Mark
2(b)(i)
. nitrification is oxidation, denitrification is
2. nitrification requires {oxygen / aerobic
obic st take
)
1reduction ;
conditions}, denitrification requires anaerconditions / removal of ammonium muplace in aerobic conditions, removal of nitrate in anaerobic conditions ;
(2
Question Number
Answer Mark
2(b)(ii)
. ammonium ;
2. ammonium is {oxidised / converted / nitrified}
3. nitrates ;
4. itrates then need to be removed (by
ax
1
to nitrites ; to ndenitrification) ;
m(3)
36 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(c)(i)
e {enrichment / increase / eq} of {nutrients /
) thminerals / eq} ;
(1
Question Number
Answer Mark
2(c)(ii)
1. increased {algae / plant} growth / reference to
2. lgae / plants} die ;
3. ference to increased {decomposition / eq} by
4.
5. sh suffocate / eq ;
. reference to toxins (from algae) killing fish ;
7. reference to lack of food for fish ;
ax
algal bloom ; {a
reaerobic {bacteria / fungi / eq} ; ses up oxygen (in water) / BOD increases ; u
fi
6
m(4)
37 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(a)(i)
87 528 – 50 304 OR 22 953 + 14 271 ;
37 224 ;
(2)
Question Number
Answer Mark
3(a)(ii)
1. biomass can vary {seasonally / eq} ; 2. idea of fluctuations in different trophic levels
may not coincide / eq ; 3. energy flow {takes account of time / cancels
out fluctuations} / biomass only at one time / eq ;
4. reference to variable content of {biomass /
organic} material ;
max (2)
Question Number
Answer Mark
3(b)
1. reference to {biomass / organisms / bodies /
eq} washed away (as stream flows) ; 2. reference to decay / eq ;
3. excretion ;
max (2)
Question Number
Answer Mark
3(c)(i)
1. nitrate decreased, ammonium and phosphate
increased ; 2. phosphate increased more than ammonium ;
3. nitrate decrease much larger than increase in
other two ions ;
4. suitable manipulation of data to support a comparison ;
max (3)
38 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(c)(ii)
1. numbers of primary consumers {increase /
decrease} if producers {increase / decrease} ;
te
rtiary consumers {depend / feed} on on
2.secondary consumers which {depend / feed} primary consumers ;
(2)
Question Number
Answer Mark
3(d)
1. (increase in) {grazing animals / cattle} may
2.
3. removes protective canopy /
4. ence to {plant / tree} roots {bind /
5. heat / rain / wind} ;
y /
anges in local weather
8. ed by increased
ax
lead to {overgrazing / increased trampling} ;
{overgrazing / trampling} removes {plant cover / eq} ;
deforestationeq ;
referstabilise} soil ;
soil exposed to {
6. (therefore) soil {dries out / washes awablows away} ;
reference to ch7.pattern (due to plant loss) ;
reference to salinisation causevaporation from surface of exposed soil ;
m(4)
39 0906 8040/9040, 8042/9042
Unit 4 (6104/Core) - Respiration and coordination Question Number
Answer Mark
1(a)
outer segment labelled R / rhodopsin ;
(1)
Question Number
Answer Mark
1(b)
1. rhodopsin is {bleached / broken down / split / eq} (in bright light) ;
2. (re-)synthesized / eq in {dark / dim / eq} ;
3. this takes time / eq ;
4. reference to dark adaptation ;
max (3)
40 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)(i)
sensory / afferent / pseudo-unipolar (neurone ) ;
(1)
Question Number
Answer Mark
2(a)(ii)
1. {receive / eq} the {impulse / stimulus / eq }
from {receptor /sense} {organ / cell} ;
2. {pass impulse to / eq} {CNS / brain / spinal cord / {relay / effector /eq} neurone} ;
(2)
Question Number
Answer Mark
2(a)(iii)
arrow drawn points upwards from dendrite to synknob ;
aptic
(1)
Question Number
Answer Mark
2(b)
1. depolarisation of (neurone) membrane ; 2. {rapid / brief / sudden / temporary} /
reference to changes from negative to positive (on the inside) ;
3. caused by {inflow / eq} of sodium ions /
increased permeability to Na+ ;
max (2)
41 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(a)(i)
B matrix ; C crista / inner membrane ;
(2)
Question Number
Answer Mark
3(a)(ii)
C ;
(1)
Question Number
Answer Mark
3(b)(i)
1. reference to reaction components used up /
not available, e.g. glucose, ADP, phosphate ; 2. no source of {electrons / hydrogen} to {react
with / eq} oxygen / eq ;
3. yeast switch to anaerobic respiration / aerespiration stops / eq ;
robic
5. idea of oxygen dissolving into solution from the
4. this is because oxygen levels are too low / eq ;
air / oxygen levels (in suspension) are maintained / eq ;
max (2)
Question Number
Answer Mark
3(b)(ii)
. (antimycin A) prevents {electrons / H+}
} ;
2. oxygen is not reduced / does not form water
)
1
{reaching oxygen / pass along chain} / eq
/ does not act as (final) electron acceptor / eq ;
(2
42 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(b)(iii)
1. ATP production {decreases / slows down} /
eq ; Then any two from:
2. idea of electron transport chain is where {most / eq} ATP produced ;
3. {oxidative phosphorylation / eq} {stops /
eq} ;
4. Krebs cycle {stops / eq} ;
5. idea that {NADH / eq} cannot be reoxidised ;
6. reference to {yeast switches to anaerobic
respiration / ATP produced in glycolysis} ;
max (3)
43 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(a)(i)
1. increase in age, slower rate / eq ; 2. credit quantitative manipulation of figures
e.g at age 30 there is a decrease of 2.7 mmol dm-3 / at age 80 the decrease is 0.6 mmol dm-3 ;
3. credit quantitative comparison of two ages
e.g. 80 is 4½ times lower than 30 / rate at 30 is 2.7 mmol dm-3 but at 80 it is much slower at 0.6 mmol dm-3 ;
max (3)
Question Number
Answer Mark
4(a)(ii)
change in activity in {pancreas / liver} {change / decrease} in amount of insulin, change in {seuptake} by body cells ;
nsitivity /
(1)
Question Number
Answer Mark
4(b)(i)
1. correct readings from graph (8.8 and 4.8) ; 2. correct subtraction (4.0) and x 100 ;
3. correct division (÷ 4.8) to give 83(.3) ;
(3)
44 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(b)(ii)
1. stimulates the conversion of {glycogen to
glucose / glycogenolysis} / eq ; 2. reference to activation of enzymes ;
3. stimulates uptake of amino acids (into cells) /
eq ;
4. (amino acids / fatty acids) are converted inglucose / gluconeogenesis / eq ;
to
5. glucose released into {blood / hepatic vein /
eq} ;
6. (glucagon) inhibits insulin production / eq ;
max (3)
Question Number
Answer Mark
4(b)(iii)
any appropriate named hormone e.g. adrenaline ;
(1)
45 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(a)
1. {active transport / eq} of {Na+ / Cl-} out of
ascending limb ; 2. correct reference to {water potential / eq}
(in medulla) ;
3. water passes out of {collecting duct / descending limb} (into blood / vasa recta / medulla) / eq ;
4. correct reference to osmosis ;
5. reference to counter-current mechanism ;
6. the longer the loop the greater the effect /
eq ;
7. reference to ascending limb being impermeable to water ;
max (5)
Question Number
Answer Mark
5(b)
1. reference to reduces dehydration ; 2. (ADH) increases permeability {of collecting
duct / distal convoluted tubule} to water ;
3. reference to {aquaporins / water channels / eq} ;
4. more water {reabsorbed / absorbed into the
blood} ;
5. correct reference to osmosis ;
6. idea that a more concentrated solution is produced ;
max (4)
46 0906 8040/9040, 8042/9042
Unit 4A (6104/01) - Microbiology and biotechnology Question Number
Answer Mark
6
any 2 correct boxes for 1 mark ;;;;
Stage of Gram stain
Appearance of Gram negative bacteria
Appearance of Gram positive bacteria
purple
purple
purple
purple
colourless
purple
pink / red
purple
(4)
47 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)
1. reference to infection / bacteria entering
{cells / macrophases / tissues} ;
2. reference to tissue destruction ;
3. credit correct details of tuberculosis ;
max (2)
Question Number
Answer Mark
7(b)(i)
1. (overall) decrease in number of cases / eq ; 2. {sharp / fast / eq} decrease between 1980 an
{1984 to 1988} ; d
3. idea of {fluctuation / smaller decrease}
between {1987 / 1988} and {2003 / 2004} ;
4. credit correct manipulation of figures ;
max (2)
Question Number
Answer Mark
7(b)(ii)
1. treatment is not improving / eq ; 2. bacteria are becoming resistant to antibiotics /
eq ;
3. idea that pulmonary TB does not account for {all / majority} of deaths ;
max (2)
48 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(a)(i)
1. a drop in pH to {5.5 to 5.3} has no effect on
viscosity ; 2. drop in pH from {5.5 to 5.3} causes an inc
in viscosity / eq ; rease
(2)
Question Number
Answer Mark
8(a)(ii)
1. reference to lactic acid {fermentation /
production} ; 2. by {bacteria / Lactobacilli} ;
3. (appropriate acid) causes drop in pH ;
4. (fall in pH) causes {coagulation / eq} of (milk)
proteins / eq ;
max (3)
Question Number
Answer Mark
8(b)
1. reference to use of Penicillium ; 2. reference to {(fed) batch fermentation /
secondary metabolite / production at end of growth phase} ;
3. reference to {nutrients / carbon source / named carbon source / nitrogen source / named nitrogen source} (at start) ;
4. reference to {maintaining temperature (25-27°C) / use of water jacket} ;
5. reference to maintaining pH (6.8-7.7) ;
6. reference to aeration / eq ;
7. reference to addition of {growth factor / phenylacetic acid} ;
8. reference to {extraction from / secretion} of penicillin into culture fluid ;
max (4)
49 0906 8040/9040, 8042/9042
Question Number
Answer Mark
9(a)
reference to or description of {absorbance / transmission} ;
(1)
Question Number
Answer Mark
9(b)
1. 0.09 – 0.07 x 100(%) ; 2. divided by 0.07 = 28.57(%) ;
(2)
Question Number
Answer Mark
9(c)
1. no change in turbidity from {0 – 1 / 3 – 4 / 9 –
10} cell numbers remain constant / eq ; 2. (0 – 1 hour) bacteria {acclimatises / sy
enzymes} / eq ; nthesises
7. (4 – 9 hours) {second nutrient / carbon source}
3. (3 – 4 hours) synthesis different enzymes ;
4. (9 – 10 hours) nutrient {run out / eq} / toxin
built up / eq ;
5. turbidity increases from {1 – 3 / 4 – 9} cell numbers are increasing ;
6. (1 -3 hours (first)) first nutrient metabolised ;
used ;
max (4)
50 0906 8040/9040, 8042/9042
Question Number
Answer Mark
9(d)
. reference to serial dilution / description of
. (0.1 – 1 cm bacterial suspension {onto /
3. reference to plating technique / eq ;
4. range of dilutions plated / replicates used ;
5. count colonies and multiply by dilution factor
6. reference to sampling at regular time
7. reference to agitation of culture ;
8. reference to aseptic technique ;
ax
1two steps ;
3)2into} solid agar ;
for cells/cm3 ;
intervals ;
m(4)
51 0906 8040/9040, 8042/9042
Unit 4B (6104/02) - Food science Question Number
Answer Mark
6
Method of preservation Means of reducing food spoilage
prevents growth of aerobic
microorganisms / delays growth of
facultative anaerobes ;
decreases pH / increases acidity / eq ;
prevents rancidity (of lipids) / prevents
oxidation / reference to reduction of free
radicals;
heat treatment / high temperature (62 - 72ºC) ;
(4)
52 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)
1. energy needed (by an individual) for {e
body processes / at rest / eq} ; ssential
mping
2. named example of body process e.g. puof heart / ventilation / maintenance of body temperature / chemical processes ;
(2)
Question Number
Answer Mark
7(b)(i)
1. (energy expenditure of) males is greater than
that for females (for all activities) / eq ;
2. the greatest difference is during running and swimming / eq ;
3. manipulation of figures to compare males an
females (with units) ; d
max (2)
Question Number
Answer Mark
7(b)(ii)
1. idea that males could be putting in more ef
than females ; fort
2. males were heavier than females / eq ;
3. males have faster metabolic rate ;
4. reference to activity not standardised / eq ;
max (2)
53 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(a)
1. cholesterol increases the chances of de
coronary heart disease / eq ; veloping
2. HDL cholesterol decreases the chances of
developing coronary heart disease / eq ; 3. credit quantitative manipulated figures ;
max (2)
Question Number
Answer Mark
8(b)
Maximum of two marks from either list Cause an increase in coronary heart disease:
high levels of LDL ; high levels of cholesterol ; high levels of saturated fat ; high levels of salt ; excess energy intake ;
Cause a decrease in coronary heart disease:
HDL ; NSPs / pectins / gums ; antioxidants / vitamin C ; unsaturated fat ;
max (3)
54 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(c)
1. help to reduce incidence of cancer / eq ;
2. decreases transit time of stools / eq (in large
intestine) ;
3. idea of reduces contact time of carcinogens with wall of intestine ;
4. reference to digestion (of NSP) by bacteria ;
5. producing metabolites that help to prevent
cells becoming cancerous / eq ;
6. reference to reducing {constipation / IBS / diverticulitis} ;
7. softens stools / eq ;
8. idea of reducing pressure on walls of intestine ;
9. which would form tears / pouches (in
diverticulitis) ;
max (4)
55 0906 8040/9040, 8042/9042
Question Number
Answer Mark
9(a)(i)
cabbage ; salt / sodium chloride ;
(2)
Question Number
Answer Mark
9(a)(ii)
any 2 from: Enterobacter (chloacae), Leuconostoc (mesanteroides), {Lactobacillus / eq} (plantarum), {Lactobacillus / eq} (brevis) lactic acid bacteria ;;
(2)
Question Number
Answer Mark
9(b)(i)
1. correct subtraction ; 2. correct division to give answer of 1 ;
(2)
Question Number
Answer Mark
9(b)(ii)
1. up to two days no change in pH ; 2. due to bacteria acclimatising / synthesising
enzymes ;
3. decrease in pH between {2 and 6 / 8 and 13} days ;
4. due to bacteria producing (organic) acid;
5. increase in pH between {6 and 8 / 13 and 15}
days ;
6. due to bacterial {breakdown/ metabolism }of some of the acids produced ;
max (4)
56 0906 8040/9040, 8042/9042
Question Number
Answer Mark
9(b)(iii)
reference to lowest pH reached / to allow cabbage toabsorb acid / to allow changes to occur to the flavo/ to allow gas production to stop before packagingeq ;
ur
/
(1)
57 0906 8040/9040, 8042/9042
Unit 4C (6104/03) - Human health and fitness Question Number
Answer Mark
6
any 2 correct boxes for 1 mark ;;;;
One location One function
synapse / terminal bouton / synaptic cleft / {neurotransmitter / eq}/
motor end plate / neuromuscular junction
initiate muscle
contraction / slows down heartbeat / eq
(skeletal) muscle
{phosphorisation of ADP / eq} / energy
store / eq
bone / teeth
(mechanical) strength
/ eq
muscle
oxygen store / eq
(4)
58 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)
1. (individuals training have) higher energy
demands / carbohydrates provide {energy / ATP} ;
2. reference to supplies carbohydrate to glucose ;
3. reference to conversion of glucose to
4. reference to glycogen stores in muscle ;
glycogen ;
max (2)
Question Number
Answer Mark
7(b)(i)
. both decrease during exercise and increase
. (during exercise) {greater / faster} decrease in
3. (after exercise) {more glycogen replaced /
4. correct comparative manipulation of data ;
ax
1after exercise ;
2glycogen in individual on high carbohydrate diet / eq ;
glycogen replaced faster} in individual on highcarbohydrate diet / eq ;
m(2)
Question Number
Answer Mark
7(b)(ii)
. high carbohydrate reference to more glucose
2. high carbohydrate idea that {surplus / eq}
)
1(available) ;
glucose remains from glycogen breakdown during exercise ;
(2
59 0906 8040/9040, 8042/9042
Question Number
Answer Mark
8(a)(i)
. (during first two minutes / up to 5 minutes)
. (after this) {great / eq} decrease in energy
)
1{both increase / rise in oxygen consumption asincrease in energy expenditure / eq} ;
2expenditure but oxygen consumption {rises a little and falls / plateaus / changes very little / eq} ;
(2
Question Number
Answer Mark
8(a)(ii)
. idea that during exercise oxygen demand of
. reference to anaerobic respiration ;
3. produces lactic acid / eq ;
4. (lactic acid) results in muscle fatigue ;
5. oxygen needed to remove lactic acid / eq ;
6. oxidising it to carbon dioxide and water / eq ;
ax
1muscles exceeds supply ;
2
m(3)
Question Number
Answer Mark
8(b)
. ATP is source of energy that can be used (by
. (during muscle contraction) myosin binds to
3. myosin head {swivels / eq} to move actin /
4. and this
1muscles) directly / eq ;
2actin / eq ;
eq ;
uses ATP ;
5. ATP needed to detach myosin (from actin) /
6. so that process can continue / eq ;
ax
eq ;
m(4)
60 0906 8040/9040, 8042/9042
Question Number
Answer Mark
9(a)(i)
1. (occupational) lung diseases / eq ; 2. (caused due to) inhalation of dust / eq ;
3. occurs over time / effects not seen for at least
10 years / eq ;
4. dust particles engulfed by macrophages / eq ;
5. formation of nodular lesions / eq ;
6. ref to fibrosis / collagen network ;
7. leads to necrosis / cavities (within the lungs) / eq ;
8. severe cases ischaemia / shortage of oxygen /
hypoxemia / eq ;
max (4)
Question Number
Answer Mark
9(a)(ii)
asbestosis/ silicosis / bauxite fibrosis / berylliosis / siderosis / labrador lung / byssinosis ;
(1)
61 0906 8040/9040, 8042/9042
Question Number
Answer Mark
9(b)(i)
1. (1020 - 435) x 100(%) ; 2. divided by 435 = 134.48(%) ;
(2)
Question Number
Answer Mark
9(b)(ii)
rs
fluctuate / eq ;
2. 2001 to 2002 {largest / eq} increase in numbers
3. 2002 to 2004 number relatively steady / eq ;
4. / eq} decrease / eq ;
5. no overall trend / eq ;
max (3)
1. 1993 to 2001 no real pattern / numbe
/ eq ;
2004 to 2005 {large
Question Number
Answer Mark
9(c) most miners are men / eq ; (1)
62 0906 8040/9040, 8042/9042
Unit 5B (6105/01) - Genetics, evolution and biodiversity Question Number
Answer Mark
1(a)
cop
pice / coppiced / coppicing ;
(1)
Question Number
Answer Mark
1(b)
ls /
q} ation / each year /eq} ;
ground level ;
4. to form {stools / stump / eq} ;
. reference to (side) {shoots / poles / eq} allowed to grow / eq ;
r several years / at least 3 years ;
max
1. woodland divided into {areas / blocks / fel
eq} ; 2. idea of different {areas / blocks / fells / e
harvested in {rot
3. reference to cutting down trees (close) to
5
6. fo (4)
Question Number
Answer Mark
1(c)
1. different {environmental / abiotic / named
abiotic} factor(s) within the {wood / eq} ; 2. (because) {areas / eq} are at different stages
of development / eq ; 3. idea of a {range of / new / diversity of}
{habitats / niches / food sources} {created / maintained / eq} ;
max (2)
63 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)
(plant) growth substances / PGS / growth regulator / GR ;
) P
(1
Question Number
Answer Mark
2(b)(i)
. A is largest / A has {developed / grown} the
. B shows no signs of {development / growth /
3. C {grown / developed} to approximately 2/3
4. reference to another visible difference e.g.
ax )
1most / A is larger than {B / C / both} ;
2eq} / very small / eq ;
to 3/4 the size of A / eq ;
shape, depth of colour ;
m(2
64 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(b)(ii)
{development / ripening / growth / eq} ; 2. {auxin / PGS} {formed / eq} by {achenes / eq} ;
iffuses) into {flesh / cells / strawberry / eq};
[NB if awarded, do not award mp7]
. (therefore) strawberry does not {develop /
. auxin (in paste) {stimulates / causes / eq}
iven]
8. reference to another PGS involved in
{development / ripening / growth / eq} ;
9. named example of another suitable PGS ;
10. reference to enhanced effect on auxin with another PGS ;
11. reference to synergism ;
max (5)
1. {auxin / PGS} needed for strawberry
3. (d
4. no {auxin /PGS} when {achenes /eq} removed ;
5ripen / grow / eq} in B ;
6
strawberry {development / ripening / growth /eq} in C ;
7. (diffuses) into {flesh / cells / strawberry / eq};
[NB do not award if mp3 g
65 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(a)
1. reference to {controlled / eq} by a pair
alleles ; of
eles / eq ;
ax )
2. reference to {different / alternative} forms of
all
3. reference to same locus ;
m(2
Question Number
Answer Mark
3(b)
1. erozygous for both characteristics / eq ;
2. 3. bilateral is dominant (over radial) / accept
4. correct use of term {genotype / phenotype} ;
ax )
all {offspring / F1} are het
colour shows codominance / eq ;
converse ;
m(3
Question Number
Answer Mark
3(c)
1. use of} symbols ;
radial given ;
3. correct gametes for both ;
4. genotypes of expected offspring ;
5. phenotypes linked to genotypes of offspring ;
6. 1 :1 :1 :1 ;
max (4)
key {showing /
2. genotypes of F1 and white,
66 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(a)(i)
. reference to active {transport / uptake} / eq ;
3. s / protein carriers /
transport proteins / eq} in membrane ;
ax
1. ATP as a source of energy ;
2
for {proton pump
m(2)
Question Number
Answer Mark
4(a)(ii)
. increases surface area / large SA : V ;
2. maximises / eq}
uptake ;
. reference to more
1
(increased SA) {increases /
3 {proton pumps / protein
ax ) carriers / transport proteins / eq} ;
m(2
Question Number
Answer Mark
4(b)(i)
pigment plant sun shade mp
1 g/mass abc both less or more ;
2 g/area a / c both more or less ;
3 g/area b M same or same ;
4 g/area b T less or more ;
max (3)
67 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(b)(ii)
1. idea of less light available to shaded plants /
eq ;
2. re pigment able to absorb more light (in shade) ;
3. asses through leaf / eq ;
4. pigments absorb different wavelengths ;
5. light in sun and shade may have different wavelengths / eq ;
6. examples quoted ;
7. otosynthesis rates maintained in shade plants ;
ax )
mo
more pigment per mass means less light p
m(4
idea of ph
68 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(a)(i)
1. produces {sucrase / carbohydrase} ; 2. ference to {hydrolysis / breakdown} of
3. form glucose and fructose ; ax )
reglycosidic bond ;
to
m(2
Question Number
Answer Mark
5(a)(ii)
1. , carbohydrates for nergy ;
2. larva (needs more protein because it) is main
3. adult (needs more carbohydrate because it) is {more active / flies} ;
ax (2)
proteins used for growthe
growth stage ;
m
Question Number
Answer Mark
(b) 1. biological (control) ;
Then any TWO from:
2. crops not {contaminated / toxic / eq} / no bioaccumulation ;
3. pesticides less specific / eq ;
4. long-term balance can be established /
pesticides may need to be applied several times / reference to resurgence / reference to resistance ;
5. no health risk to glasshouse workers / eq ;
6. adult lacewings might aid pollination / eq ;
7. suitable for organic crops ;
max (3)
5
69 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(c)
1. reference to sympatric speciation ;
3. sub-populations are reproductively isolated /
4. gene flow {inhibited / restricted / eq}
(between sub-populations) ;
5. mutations arise (in sub-populations) ;
7. sub-populations become {phenotypically /
offspring / eq ;
2. reference to prezygotic mechanism ;
eq ;
max (5)
6. (cause) gene pools diverge / eq ;
physically / physiologically} different from each other ;
8. so that successful mating cannot occur between them / no fertile
70 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(a)
1. carbon dioxide is a greenhouse gas / eq ;
e removed from atmosphere {long ago / eq} and
ntly / eq} ;
n tain balance /
are carbon neutral / eq} ;
ax )
2. idea of fossil fuels release carbon dioxid
biofuels release carbon dioxide removed {rece
3. fossil fuel use increases carbon dioxide i
atmosphere and biofuels {main
m(2
Question Number
Answer Mark
6(b)
1. ith {petrol / petroleum / eq} ;
eq ;
{mixed / eq} w
2. {10 / 20} % ethanol to {90 / 80} % petrol /
(2)
Question Number
Answer Mark
6(c)(i)
1. reference to {many times greater / a lot
higher / eq} ;
2. mean from other sources = 1000 dm3 (per hectare) ;
3. palm seeds approximately {4 times / 300%}
greater than other sources ;
max (3)
Question Number
Answer Mark
(c)(ii) 1. more income / eq ;
2. create more employment / eq ;
3. prevents increased urbanisation / maintains
rural population / eq ;
4. reduce dependency on fossil fuels / eq ;
5. reduce need to import fuels / eq ;
max (2)
6
71 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(d)
1. reference to legislation / eq ;
2. reference to {EU Habitats Directive / Natura
2000} ;
3. promotes conservation of (natural) habitats / eq ;
4. to {maintain / encourage} biodiversity eq ;
5. example of specific {ecosystems / habitats} in
annexe 1 ;
max (3)
72 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)
biotic are caused by living organisms, abiotic by non-living ;
(1)
Question Number
Answer Mark
7(b)
1. named animal in suitable named habitat ;
2. suitable abiotic factor and how it is measured ;
3. suitable technique ;
(3)
Question Number
Answer Mark
7(c)(i)
1. haemoglobin is found in {red blood cells /
erythrocytes} ;
2. haemoglobin can bind {temporarily / reversibly} to oxygen / haemoglobin has high affinity for oxygen ;
3. reference to (haemoglobin molecule has) four
{iron-containing / haem} groups ;
4. each {iron-containing / haem} group combines with one oxygen molecule / four oxygen molecules can combine with each haemoglobin molecule ;
max (3)
73 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(c)(ii)
1. at{low altitudes / high ppO2}, no difference
in % saturation (between the two mice) ;
2. {as altitude increases / ppO2 falls} dissociation curve of high altitude {haemoglobin / mice} is {to the left / above} ;
3. (so) oxygen combines more easily with high
altitude haemoglobin / eq ;
4. credit manipulation of figures ;
5. at high altitudes, mice with high altitude haemoglobin are at an {advantage / eq} ;
6. (high altitude haemoglobin) allows mice to {be active / move around / eq} ;
max (4)
74 0906 8040/9040, 8042/9042
Unit 5H (6115/01) - Genetics, human evolution and biodiversity Question Number
Answer Mark
1(a)
coppice / coppiced / coppicing ;
(1)
Question Number
Answer Mark
1(b)
1. woodland divided into {areas / blocks / fells /
eq} ; 2. idea of different {areas / blocks / fells / eq}
harvested in {rotation / each year /eq} ;
3. reference to cutting down trees (close) to ground level ;
4. to form stools / stump / eq ;
5. reference to (side) {shoots / poles / eq}
allowed to grow / eq ;
6. for several years / at least 3 years ;
max (4)
Question Number
Answer Mark
1(c)
1. different {environmental / abiotic / named
abiotic} factor(s) within the {wood / eq} ; 2. (because) {areas / eq} are at different stages
of development / eq ; 3. idea of a {range of / new / diversity of}
{habitats / niches / food sources} {created / maintained / eq} ;
max (2)
75 0906 8040/9040, 8042/9042
Question Number
Answer Mark
chorionic villus sampling / amniocentesis ;
(1) 2(a)(i)
Question Number
Answer Mark
2(a)(ii)
1. miscarriage / abortion /eq ; 2. damage / injury to { mother / fetus} ;
3. infection to {mother / fetus} ;
max (2)
Question Number
Answer Mark
2(b)
1. Down’s syndrome ;
Then any four from:
2. reference to {extra chromosome / trisomy /
three chromosomes} at 21 ;
3. reference to non-disjunction ;
4. chromosomes fail to separate / eq ;
5. during anaphase 1 / meiosis 1 ;
6. {egg / oocyte / ovum} has 24 chromosomes / has an extra chromosome ;
max (5)
76 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3(a)
1. reference to {controlled / eq} by a pair of
alleles ; 2. reference to {different / alternative} forms of
alleles / eq ;
3. reference to same locus ;
max (2)
Question Number
Answer Mark
3(b)
1. all {offspring / F1} are heterozygous for both
characteristics / eq ;
2. colour shows codominance / eq ; 3. bilateral is dominant (over radial) / accept
converse ;
4. correct use of term {genotype / phenotype} ;
max (3)
Question Number
Answer Mark
3(c)
1. key {showing / use of} symbols ; 2. genotypes of F1 and white, radial given ;
3. correct gametes for both ;
4. genotypes of expected offspring ;
5. phenotypes linked to genotypes of offspring ;
6. 1 :1 :1 :1 ;
max (4)
77 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(a)(i)
1. sequence of {nucleotides / bases} on DNA /
{length / section} of DNA ; 2. codes for {sequence of amino acids /
polypeptide} ;
3. reference to triplet of bases corresponds to an amino acid ;
max (2)
Question Number
Answer Mark
4(a)(ii)
1. formed by condensation (reaction) ; 2. between (two) amino acids ; 3. between carboxyl group (of amino acid 1) and
amino group (of amino acid 2) ;
max (2)
Question Number
Answer Mark
4(b)
1. Neanderthals, (modern) human and
chimpanzee most closely related ; 2. (because) sequences identical ;
3. idea of orang-utan, gorilla and monkey
relationship rank order ;
4. (because) orang-utan has 1 difference, gorilla 2 differences and monkey 3 differences ;
5. one difference described ;
6. idea of number of differences indicates
divergence related to geological time ;
max (4)
78 0906 8040/9040, 8042/9042
Question Number
Answer Mark
4(c)
1. reference to {carbon / potassium-argon}
dating ; 2. reference to decay of {radio-isotope / 14C /
40K} is {predictable / eq} ;
3. reference to {carbon / potassium} taken into skull material when Neanderthal was {alive / eq} ;
4. reference to how skull is aged by reference
to data from decay of isotopes ;
max (3)
79 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(a)(i)
1. produces {sucrase / carbohydrase} ; 2. reference to {hydrolysis / breakdown} of
glycosidic bond ;
3. to form glucose and fructose ;
max (2)
Question Number
Answer Mark
5(a)(ii)
1. proteins used for growth, carbohydrates for
energy ;
2. larva (needs more protein because it) is main growth stage ;
3. adult (needs more carbohydrate because it) is {more active / flies} ;
max (2)
Question Number
Answer Mark
5(b)
1. biological (control) ;
Then any TWO from:
2. crops not {contaminated / toxic / eq} / no bioaccumulation ;
3. pesticides less specific / eq ;
4. long-term balance can be established /
pesticides may need to be applied several times / reference to resurgence / reference to resistance ;
5. no health risk to glasshouse workers / eq ;
6. adult lacewings might aid pollination / eq ;
7. suitable for organic crops ;
max (3)
80 0906 8040/9040, 8042/9042
Question Number
Answer Mark
5(c)
1. reference to sympatric speciation ;
2. reference to prezygotic mechanism ;
3. sub-populations are reproductively isolated /
eq ;
4. gene flow {inhibited / restricted / eq} (between sub-populations) ;
5. mutations arise (in sub-populations) ;
6. (cause) gene pools diverge / eq ;
7. sub-populations become {phenotypically /
physically / physiologically} different from each other ;
8. so that successful mating cannot occur
between them / no fertile offspring / eq ;
max (5)
81 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(a)
1. carbon dioxide is a greenhouse gas / eq ; 2. idea of fossil fuels release carbon dioxide
removed from atmosphere {long ago / eq} and biofuels release carbon dioxide removed {recently / eq} ;
3. fossil fuel use increases carbon dioxide in
atmosphere and biofuels {maintain balance / are carbon neutral / eq} ;
max (2)
Question Number
Answer Mark
6(b)
1. {mixed / eq} with {petrol / petroleum / eq} ;
2. {10 / 20} % ethanol to {90 / 80} % petrol / eq ;
(2)
Question Number
Answer Mark
6(c)(i)
1. reference to {many times greater / a lot
higher / eq} ;
2. mean from other sources = 1000 dm3 (per hectare) ;
3. palm seeds approximately {4 times / 300%}
greater than other sources ;
max (3)
Question Number
Answer Mark
6(c)(ii)
1. more income / eq ;
2. create more employment / eq ;
3. prevents increased urbanisation / maintains
rural population / eq ;
4. reduce dependency on fossil fuels / eq ;
5. reduce need to import fuels / eq ;
max (2)
82 0906 8040/9040, 8042/9042
Question Number
Answer Mark
6(d)
1. reference to legislation / eq ;
2. reference to {EU Habitats Directive / Natura
2000} ;
3. promotes conservation of (natural) habitats / eq ;
4. to {maintain / encourage} biodiversity eq ;
5. example of specific {ecosystems / habitats} in
annexe 1 ;
max (3)
83 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(a)
biotic are caused by living organisms, abiotic by non-living ;
(1)
Question Number
Answer Mark
7(b)
1. named animal in suitable named habitat ;
2. suitable abiotic factor and how it is measured ;
3. suitable technique ;
(3)
Question Number
Answer Mark
7(c)(i)
1. haemoglobin is found in {red blood cells /
erythrocytes} ;
2. haemoglobin can bind {temporarily / reversibly} to oxygen / haemoglobin has high affinity for oxygen ;
3. reference to (haemoglobin molecule has) four
{iron-containing / haem} groups ;
4. each {iron-containing / haem} group combines with one oxygen molecule / four oxygen molecules can combine with each haemoglobin molecule ;
max (3)
84 0906 8040/9040, 8042/9042
Question Number
Answer Mark
7(c)(ii)
1. at{low altitudes / high ppO2}, no difference
in % saturation (between the two mice) ;
2. {as altitude increases / ppO2 falls} dissociation curve of high altitude {haemoglobin / mice} is {to the left / above} ;
3. (so) oxygen combines more easily with high
altitude haemoglobin / eq ;
4. credit manipulation of figures ;
5. at high altitudes, mice with high altitude haemoglobin are at an {advantage / eq} ;
6. (high altitude haemoglobin) allows mice to {be active / move around / eq} ;
max (4)
85 0906 8040/9040, 8042/9042
Unit 6 (6106-02) - Written Alternative to Coursework Question Number
Answer Mark
1(a)
Number of Mimosa seeds / 0.25 m-2
In floodplain habitat
In woodland habitat
Without mining moths
With mining moth
Without mining moth
With mining moth
500 194 22 32 505 200 28 34 605 241 29 35 606 255 33 38 729 306 33 39
751 340 38 48 Median number
758 350 42 52 805 369 46 55 825 400 48 60 830 491 51 62
900 512 61 65 Median number
751 340 38 48
neat tables correctly formatted including medians (only if medians identified) ; correctly labelled columns with units ; numbers ranked ; all medians correct ;
(4)
86 0906 8040/9040, 8042/9042
Question Number
Answer Mark
1(b)
A graph correctly orientated with labelled axes and
key ; F bar chart {for medians / for means (if
calculated)} OR histogram for size classes ; Floodplain Number classes
Not infected
Infected
101 – 200 2 201 – 300 2 301 – 400 5 401 – 500 1 501 – 600 2 1 601 – 700 2 701 – 800 3 801 – 900 4
Woodland Number classes
Ninfected
fected ot In
21 – 30 3 0 31 – 40 3 5 41 – 50 3 1 51 – 60 1 3 61 – 70 1 2
plotted correctly ;
(3) P data
Question Number
Answer Mark
1(c)
there is no significant difference between {the number of seeds produced in uninfected and infected Mimosa in either the floodplain or woodland habitats / the effect of mining moths in the two habitats / eq} ;
(1)
87 0906 8040/9040, 8042/9042
Question Number
Answer Mark
1(d)
there is a significant difference between {the (median) number of seeds produced in the floodplain, ut not in the woodland / the effect of the mining
moths in the two habitats / eq} ; since the smallest U / U2 value is less than 30 in the floodplain habitat, but not in woodland ;
(2)
b
Question Number
Answer Mark
1(e)
biological control is effective in the floodplain, but not in t d ;
(1) he woodlan
88 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)
General methodology
1. plant buttercups at different densities / eq ;
2. TWO named abiotic factors for growth
controlled ;
3. stated area for each density (at least 1m x 1m) ;
sampling using quadrat of stated size (max 1m2) / method of determining suitably sized quadrat ;
thod of random sampling described ;
6. number of samples for each density
(minimum 10) ;
7. use of key to identify buttercups ;
8. count / tally total number of parent plants in quadrat and
4.
5. suitable me
number with runners / eq (note parent counts not needed if fixed densities used) ;
Specific precautions 9. any suitable precaution to ensure validity
of counts in the context of quadrat use e.g. only runners inside quadrat counted ;
10. parent plant definition in the context of
runners (e.g. plant with no incoming runners / no intact runners to older plants) ;
11. defining a runner (in the context of this
investigation) e.g. runner with a young plant OR developing bud attached ;
Repeats
12. reference to sound environmental protection ;
13. repeat two more times {not in different
season etc};
max (8)
89 0906 8040/9040, 8042/9042
Style account is concise and well-organised, there is
nical vocabulary and almost no spelling errors – 2 marks
there is some lack of organisation, limited voc 1 ma
the account lacks organisation, there is little or no technical vocabulary and many spelling errors – 0 marks
)
otal (10)
(2 T
good use of tech
abulary and a number of spelling errors – rk
Question Number
Answer Mark
2(b)
1. appropriate null hypothesis described (in terms
of significant correlation / significant difference linked to method) {accept in method} ;
2. table with all raw data (and repeats if carried
out) and units ;
3. density (shown / calculated) with SI units i.e..
m-2;
4. means calculated ;
5. suitable graphical format (scatter gram / line of best fit / bar chart) ;
6. axes with units (that correspond to summary
data) correct way round ;
7. use of (named) appropriate statistical test ;
max
)
(5
90 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(c)
Limitat
fying plant as a parent ;
3. plants not evenly distributed / eq ;
t
ntra-specific competition / species} not considered ;
5. unsuitable time / season for asexual
reproduction ; 6. difficult to control one named abiotic
factor {not if method suggests greenhouse or similar} ;
Further work
7. investigate (density-dependent) asexual reproduction in other species OR types of plants ;
8. carry out laboratory-based investigation
(on density of plants and asexual reproduction) ;
9. find density at which asexual
stops ;
10. investigate further details of density effect e.g. number of runners / young plants per parent / average length of
11. investigate relationship between density
flowers / seeds ;
(6)
ions 1. difficulty in identi
2. difficulty in identifying runners ;
4. influence of {other density-dependenfactors / i
max
reproduction
runners ;
and sexual reproduction / fruits /
91 0906 8040/9040, 8042/9042
Unit 6 (6106/03) - Synoptic Paper
Question Number
Answer Mark
1(a)(i)
1. {stimulates / eq} {ovulation / eq} ;
2. rpus
luteum / eq} ;
3. {stimulates /eq} secretion of {progesterone / oestrogen / testosterone / androgens} ;
max (2)
{stimulates / eq} {development of the co
Question Number
Answer Mark
1(a)(ii)
exocytosis / a
(1)
description of this process ;
Question Number
Answer Mark
1(a)(iii)
negative ;
(1)
Question Number
Answer Mark
1(a)(iv)
1. GnRH transported {directly / faster / straight /
2. LH tran
round t
)
(2
short distance} to the (anterior) pituitary ;
sported {in the general circulation / he body / longer distance / slowly} ;
92 0906 8040/9040, 8042/9042
Question Number
Answer Mark
1(b) 1. concentration of oestrogen increases,
concentration of progesterone decreases / eq ;
2. credit a comment on the relative change in
each e.g. change in oestrogen concentration is {less / slower} than the change in progesterone / percentage change in oestrogen is greater ;
3. credit a manipulated quantitative
comparative comment (e.g. change in estrogen is 8.5 ng per cm3, change in
progesterone is 56 ng per cm3 / change in oestrogen is 85%, change in progesterone is 35%) ;
max (2)
o
93 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(a)(i)
1. feed on dead or decaying (organic) matter /
eq ;
2. {secrete / releases} enzymes / reference to extracellular digestion ;
3. {absorb / eq} products of digestion / eq ;
max (2)
Question Number
Answer Mark
2(a)(ii)
1. {obtain nutrients / eq} from {a host / living
organism} ;
2. reference to {harm / eq} to host ;
3. (only) the parasite benefits / eq ;
max (2)
Question Number
Answer Mark
2(b)(i)
1. aphids {obtain nutrients from crop plants /
suck sap / feed on crop} ;
2. reduce crop yield / reduce productivity / eq ;
3. spread diseases / spread viruses / eq ;
4. reduce value of crop / eq ;
max (3)
Question Number
Answer Mark
2(b)(ii)
1. use of {one organism / predator / parasite} ;
2. idea of reduce number of {pests / prey} ;
(2)
94 0906 8040/9040, 8042/9042
Question Number
Answer Mark
2(c)(i)
1. use of quadrat of suitable stated area ;
2. reference to the use of {Lincoln Index /
capture-mark-recapture method} ;
3. credit correct formula for Lincoln Index ;
4. use of (sweep) net / pooter / pitfall trap ;
5. reference to counting ladybirds ;
6. population density = number (of ladybirds) per unit area / number ÷ area ;
max (3)
Question Number
Answer Mark
2(c)(ii)
1. harlequin ladybirds have increased / eq ;
2. both other species have decreased / eq ;
3. reference to {competition / niche /
competitive exclusion / breed faster / able to exploit other food sources / fewer predators / disease resistant / eat native species / eq} ;
(3)
95 0906 8040/9040, 8042/9042
Synoptic Essay mark scheme
Scientific Content (S)
Descriptor
11 (Good)
The essay demonstrates a sound understanding of the topic and contains a significant amount of material from most areas of the mark scheme, including A2 content. Suitable examples are included and the candidate has clearly and coherently linked together information from different parts of the specification.
9 (Above
average)
An above average essay, with accurate content. The essay includes a good balance of material from several areas of the mark scheme, including A2 content, and examples where appropriate. There may be some minor factual errors.
7 (Average)
The essay includes relevant information from some areas of the mark scheme, including A2 content. The candidate links together some facts and principles. Some examples are included.
ay be some minor factual errors. There m
5 (Below
average)
The essay includes some generally factually accurate and relevant material, and there is some attempt to link material from more than one area of the mark scheme. The A2 content, in particular, lacks depth and accurate details.
3 (Poor)
There are some correct facts, but the essay lacks depth and accuracy. The essay contains little or no relevant information from the A2 content.
1 (Poor)
There are very few correct facts. The essay is generally superficial and inaccurate.
0 (Poor)
No correct or relevant material is included.
Notes Marks If a scientific content mark of 0, 1, or 3 is awarded, it is very unlikely that balance mark of more than 1 is appropriate.
An essay containing AS content only can be awarded a max of 3 for
ientific content. n essay containing A2 content only can be awarded a max of 7 for
scientific content.
S = (11)
a
sc
A
96 0906 8040/9040, 8042/9042
Balance(B) Descriptor Marks
2 Most of the main topic areas outlined are covered Some discussion of each of the areas chosen, illustrated with suitable examples where appropriate Material included is all relevant to the topic and the candidate has linked information from more than one
area of the specification. Few, if any, errors
(2)
1 Some of the main topic areas outlined are covered. Some discussion of each of the areas chosen. Some irrelevant material included. There are some examples which link together different areas of the specification. ome errors
(1) S
0 Very limited account, possibly only one aspect chosen Material mostly irrelevant No examples of the candidate linking information from ifferent topics
d
Large number of errors
(0)
Coherence(C) Descriptor Marks
2 Material logically presented, with little or no repetition Essay has coherence, ideas are developed well; continuous prose used throughout Essay has an introduction and a conclusion, summing up
nctuation and grammar are sound
(2)
the main points Technical terms have been used correctly Spelling, pu
1 some ideas
developed Continuous prose used throughout The introduction and conclusion may be present, but brief Technical terms are used and generally in the correct context Spelling, punctuation and grammar are generally sound
(1)
Material is presented in an orderly way and
0 Essay style not used Material in note form or numbered points Very poor standard of spelling, punctuation and grammar
(0)
97 0906 8040/9040, 8042/9042
Question Number
Answer Mark
3
introduction could include outline structure of DNA and explanation of term GMO – basic structure of a nucleotide – phosphate –
DNA as a polynucleotide complementary base pairing and the double helix – use of plasmids as vectors – isolation of gene – roles of endonuclease and ligase – isolation of mRNA and role of reverse transcriptase - introductio plasmid replication – use of marker genes - credit references to specific examples e.g. production of chymosin and use of Agrobacterium –
(15)
deoxyribose –
purine and pyrimidine bases –
-
n of recombinant plasmid to host cell –
98 0906 8040/9040, 8042/9042
Question Answer Mark Number 4B
introduction could include outline of transport in flowering plants and need for mineral ions – uptake of ions, root hairs and active transport – diffusion of ions – pathways across root – apoplast pathway – symplast pathway – vacuolar pathway – structure and role of endodermis – structure of xylem in relation to transport – cohesion tension, transport of mineral ions in xylem – specific references to: nitrate – phosphate – magnesium – could also include a reference to transport of phosphate in phloem –
(15)
99 0906 8040/9040, 8042/9042
Question Number
Answer Mark
introduction could include outline of protein structure and how proteins are used as evidence for human evolution – mino acids and the formation of a peptide bond –
olypeptides –
primary structure, secondary structure, tertiary structure, quaternary structure –
bonding –
reference to globular proteins and fibrous proteins –
haemoglobin and collagen –
references to analysis of amino acid sequences in haemoglobin / cytochrome ; immunological studies of blood sera – serum protein precipitation as evidence for phylogenetic relationships –
(15)
5H
a p
100 0906 8040/9040, 8042/9042
Further copies of this publication are available from Edexcel Publications, Adamsway, Mansfield, Notts, NG18 4FN Telephone 01623 467467 Fax 01623 450481 Email [email protected] Code UA021146 Summer 2009 For more information on Edexcel qualifications, please visit www.edexcel.com/quals dexcel Limited. Registered in England and Wales no.4496750
Registered Office: One90 High Holborn, London, WC1V 7BH E
101 0906 8040/9040, 8042/9042