1. (a) Allow two marks for 617;
allow one mark if arithmetical error in calculation; 2
(b) (i) Moose numbers rose in absence of predators / with plenty of food;
depletion of food / spread of disease / climatic change /
resulted in fall / death; 2
(ii) Caused the moose numbers to stabilise at lower level / equivalent; 1
[5]
2. (a) Release ammonia / ammonium / ammonification;
BY Decomposers / putrefying / saprotrophic / ammonifying bacteria;
ammonia nitrite nitrate / nitrification;
BY nitrifying bacteria / named bacteria; max. 3
(b) (Interspecific) competition;
for nitrates / nitrites / ammonia / ammonium compounds; 2
[5]
[Process is stand alone - bacteria only credited if in correct context.]
3. (a) (i) All (living) organisms/populations found in an ecosystem/in a habitat/in an
area; (NOT just ‘all species present’/’no. of spp.’) 1
(ii) Habitat (/environment) + community (/described)/
abiotic and biotic factors in a defined area/named area; 1
(b) (i) 9 – 25°C 1
(ii) biotic factor: food/predators/presence of mate/competition/
disease;
abiotic factor: water current/tides/nature of substratum/O2 (conc) /
pH/toxins/light; 2
[5]
4. (a) Wood mouse; 1
(b) Decomposers/bacteria/fungi/saprophytes/saprotrophs/detritivores; 1
(c) Colonisation/pioneer species/examples from fig/seeds/fruits;
soil formation/improvement/change by organism;
succession/eq;
process repeated to climax community/forest; max. 3
diversity is reduced;
(d) {trees form food source for many species/wide range of primary consumers;
{(primary consumers/named example/are eaten by other species)
{idea that trees are the basis of food chains/food webs;
productivity of area is reduced (with loss of trees);
so fewer organisms can be supported;
habitats are lost/ecological niches are lost (with each tree species lost); max. 3
[8]
Sir George Monoux Sixth Form College 1
,5. (a) (i) All the organisms present in an area / all populations in an
area / populations of all species in an area / in an ecosystem;
NOT “all the species in an area”
(ii) Habitat + community / environment + organisms / all biotic
and abiotic factors of an area; 2
(b) (i) EITHER: More light;
More photosynthesis / fewer spp. adapted to
lower light;
OR: Warmer;
Faster metabolism / named aspect; 2 max
(ii) ‘It’ / south-facing is less hostile environment / conditions better /
favourable for plants;
Has higher (index of) diversity / more species present;
Provides more niches / described / more complex interactions
between species;
Changes in abiotic factors / named example have less influence;
Loss of one species will have less effect on food web / on the
system; 3 max
(iii) Greater variety of habitats / described – e.g. re. nesting sites /
humidity / temperature / more food / more variety of food types /
less competition for food / more niches; 1
(c) (i) EITHER: Correct answer: 280 (2 marks) ;;
OR: Correct use of data but wrong answer/
P = (40 x 42) ÷ 6 / correct formula (1 mark) ; 2 max
(ii) Sample too small / too few traps / too short a time to mix evenly;
Uneven distribution of animals / great variation trap to trap;
Birth / death of some woodlice;
Immigration / emigration;
Marking method affected woodlouse behaviour; 2 max
[12]
6. (a) (i) B – higher standard deviation; (extras CANCEL) 1
st
(ii) 1 : A (no mark)
nd
2 : Limpets have smaller H/W / smaller mean;
Limpets have (relatively) large foot area;
Better grip on rock; 3
(b) (i) Need representative / ‘typical’ / ‘reliable’ / ‘valid’ value / anomalies
less significant / chance variations less significant;
Random sampling overcomes bias / independent of observer;
Ignore ‘fair’ / ‘accurate’ 2
(ii) Use of quadrat / nearest limpet to… ;
Grid / described – e.g. tape measures / walk to random coordinates;
Method of obtaining random coordinates – tables / calculator; 3
Sir George Monoux Sixth Form College 2
, (c) Any six from:
Yellow / green OR approx. 500-600mm
1. Penetrates water better;
2. Absorbed by phycoerythrin ;
3. Red seaweeds have phycoerythrin;
4. Red seaweeds photosynthesise in deep water;
Blue AND red OR approx. 460 and 670mm
5. Penetrate water poorly;
6. Absorbed by chlorophyll;
7. Green have only chlorophyll;
8. Green seaweeds can’t photosynthesise in deep water
9. Red seaweeds have less competition from green in deeper water /
converse in shallow water; 6 max
[15]
7. (a) (i) Time interval of 1 month / too long;
Large number of mice born / added to the population in this time /
die / lost from population;
OR
12 hours is too short a time;
For mice to mix in population / be recaptured;
OR
In non-seed years number of mice is small;
So may not catch any / any marked mice; 2
Reject answers about points not covered in the question.
(ii) Number of captures will vary with number of traps set /
number of traps varies;
Standardises results;
Allows results to be compared; 2 max
(b) (i) Less than 5% / 1 in 20 probability;
Of results being due to chance / luck;
Accept converse argument relating to biological significance. 2
(ii) More food;
Therefore mice able to produce more young / more mice survive; 2
(c) (i) Mass will vary with sex / one sex is lighter / heavier /
females may be pregnant; 1
(ii) Tooth wear linked to age / diet;
Confines sample to adult mice / mice eating same food;
Otherwise age / food contributes to variation / mass; 2 max
(d) (i) Smaller surface area to volume ratio;
So lose less heat;
OR
More (subcutaneous) fat;
Insulation;
OR
More respiration;
More heat produced; 2
Sir George Monoux Sixth Form College 3
, (ii) Variation in size is genetic;
Selection for / against one extreme (general point not related to
data) / for large mice / against small mice;
Only larger mice will (survive and) breed / pass on genes;
Leads to increase in mean mass;
In cold conditions (related to figure); 3 max
(e) (i) Grey by grey;
Produces some black; 2
(ii) Find frequency / percentage / proportion of black mice;
Square root;
Use Hardy-Weinberg equation; 2 max
[20]
8. (a) Insulates nerve fibre / axon / does not allow passage of ions / charge;
Ions only pass at non-myelinated points / nodes / action potential
only occurs at node;
Saltatory conduction (is faster) / description of ‘jumping’; 2 max
(b) Rise / fall in cholesterol concentration in cytoplasm / cell;
Reject references only to plasma concentrations;
Fall / rise in cholesterol receptors (in plasma membrane);
Leads to fall / rise in cholesterol / cholesterol returns to norm; 3
(c) (i) Mutation produces receptor with different shape / tertiary structure /
not specific to LDL;
So LDL will not bind to it and be absorbed / removed from the blood;
Do not penalise ‘active site’. 2
(ii) Endothelium / lining of artery torn / damaged;
Atheroma / plaque / underlying cells come into contact with blood;
Triggers blood clotting mechanism;
OR
Artery narrowed by plaque / atheroma;
May be blocked by clot from elsewhere; 2 max
(d) 2517;
Accept 2514 or 2511 if explanation refers to start / and stop codons. 1
(e) If recessive would inherit one allele from each parent; reject ‘gene’
Parents could be heterozygotes / carriers;
Parents / heterozygotes / carriers would not show the condition;
NB points 2 and 3 may appear in one linked sentence. 2
(f) 1003.;
Two marks for reason from below:
(As dominant,) both heterozygote and homozygote at risk;
(Heterozygotes 1 in 100 so) 1000 are heterozygous;
(Homozygotes 1 in 30000 so) .3 homozygous; 3 max
[15]
9. (a) (i) Same general structure as all amino acids; = 1 mark
Same general structure as all amino acids and answer making specific
reference
to amino/ NH2 group and carboxyl/ COOH group; 2
(ii) Not normally found in proteins/ polypeptides; 1
[Note: Alternative answers must fit with information provided
in passage]
Sir George Monoux Sixth Form College 4
allow one mark if arithmetical error in calculation; 2
(b) (i) Moose numbers rose in absence of predators / with plenty of food;
depletion of food / spread of disease / climatic change /
resulted in fall / death; 2
(ii) Caused the moose numbers to stabilise at lower level / equivalent; 1
[5]
2. (a) Release ammonia / ammonium / ammonification;
BY Decomposers / putrefying / saprotrophic / ammonifying bacteria;
ammonia nitrite nitrate / nitrification;
BY nitrifying bacteria / named bacteria; max. 3
(b) (Interspecific) competition;
for nitrates / nitrites / ammonia / ammonium compounds; 2
[5]
[Process is stand alone - bacteria only credited if in correct context.]
3. (a) (i) All (living) organisms/populations found in an ecosystem/in a habitat/in an
area; (NOT just ‘all species present’/’no. of spp.’) 1
(ii) Habitat (/environment) + community (/described)/
abiotic and biotic factors in a defined area/named area; 1
(b) (i) 9 – 25°C 1
(ii) biotic factor: food/predators/presence of mate/competition/
disease;
abiotic factor: water current/tides/nature of substratum/O2 (conc) /
pH/toxins/light; 2
[5]
4. (a) Wood mouse; 1
(b) Decomposers/bacteria/fungi/saprophytes/saprotrophs/detritivores; 1
(c) Colonisation/pioneer species/examples from fig/seeds/fruits;
soil formation/improvement/change by organism;
succession/eq;
process repeated to climax community/forest; max. 3
diversity is reduced;
(d) {trees form food source for many species/wide range of primary consumers;
{(primary consumers/named example/are eaten by other species)
{idea that trees are the basis of food chains/food webs;
productivity of area is reduced (with loss of trees);
so fewer organisms can be supported;
habitats are lost/ecological niches are lost (with each tree species lost); max. 3
[8]
Sir George Monoux Sixth Form College 1
,5. (a) (i) All the organisms present in an area / all populations in an
area / populations of all species in an area / in an ecosystem;
NOT “all the species in an area”
(ii) Habitat + community / environment + organisms / all biotic
and abiotic factors of an area; 2
(b) (i) EITHER: More light;
More photosynthesis / fewer spp. adapted to
lower light;
OR: Warmer;
Faster metabolism / named aspect; 2 max
(ii) ‘It’ / south-facing is less hostile environment / conditions better /
favourable for plants;
Has higher (index of) diversity / more species present;
Provides more niches / described / more complex interactions
between species;
Changes in abiotic factors / named example have less influence;
Loss of one species will have less effect on food web / on the
system; 3 max
(iii) Greater variety of habitats / described – e.g. re. nesting sites /
humidity / temperature / more food / more variety of food types /
less competition for food / more niches; 1
(c) (i) EITHER: Correct answer: 280 (2 marks) ;;
OR: Correct use of data but wrong answer/
P = (40 x 42) ÷ 6 / correct formula (1 mark) ; 2 max
(ii) Sample too small / too few traps / too short a time to mix evenly;
Uneven distribution of animals / great variation trap to trap;
Birth / death of some woodlice;
Immigration / emigration;
Marking method affected woodlouse behaviour; 2 max
[12]
6. (a) (i) B – higher standard deviation; (extras CANCEL) 1
st
(ii) 1 : A (no mark)
nd
2 : Limpets have smaller H/W / smaller mean;
Limpets have (relatively) large foot area;
Better grip on rock; 3
(b) (i) Need representative / ‘typical’ / ‘reliable’ / ‘valid’ value / anomalies
less significant / chance variations less significant;
Random sampling overcomes bias / independent of observer;
Ignore ‘fair’ / ‘accurate’ 2
(ii) Use of quadrat / nearest limpet to… ;
Grid / described – e.g. tape measures / walk to random coordinates;
Method of obtaining random coordinates – tables / calculator; 3
Sir George Monoux Sixth Form College 2
, (c) Any six from:
Yellow / green OR approx. 500-600mm
1. Penetrates water better;
2. Absorbed by phycoerythrin ;
3. Red seaweeds have phycoerythrin;
4. Red seaweeds photosynthesise in deep water;
Blue AND red OR approx. 460 and 670mm
5. Penetrate water poorly;
6. Absorbed by chlorophyll;
7. Green have only chlorophyll;
8. Green seaweeds can’t photosynthesise in deep water
9. Red seaweeds have less competition from green in deeper water /
converse in shallow water; 6 max
[15]
7. (a) (i) Time interval of 1 month / too long;
Large number of mice born / added to the population in this time /
die / lost from population;
OR
12 hours is too short a time;
For mice to mix in population / be recaptured;
OR
In non-seed years number of mice is small;
So may not catch any / any marked mice; 2
Reject answers about points not covered in the question.
(ii) Number of captures will vary with number of traps set /
number of traps varies;
Standardises results;
Allows results to be compared; 2 max
(b) (i) Less than 5% / 1 in 20 probability;
Of results being due to chance / luck;
Accept converse argument relating to biological significance. 2
(ii) More food;
Therefore mice able to produce more young / more mice survive; 2
(c) (i) Mass will vary with sex / one sex is lighter / heavier /
females may be pregnant; 1
(ii) Tooth wear linked to age / diet;
Confines sample to adult mice / mice eating same food;
Otherwise age / food contributes to variation / mass; 2 max
(d) (i) Smaller surface area to volume ratio;
So lose less heat;
OR
More (subcutaneous) fat;
Insulation;
OR
More respiration;
More heat produced; 2
Sir George Monoux Sixth Form College 3
, (ii) Variation in size is genetic;
Selection for / against one extreme (general point not related to
data) / for large mice / against small mice;
Only larger mice will (survive and) breed / pass on genes;
Leads to increase in mean mass;
In cold conditions (related to figure); 3 max
(e) (i) Grey by grey;
Produces some black; 2
(ii) Find frequency / percentage / proportion of black mice;
Square root;
Use Hardy-Weinberg equation; 2 max
[20]
8. (a) Insulates nerve fibre / axon / does not allow passage of ions / charge;
Ions only pass at non-myelinated points / nodes / action potential
only occurs at node;
Saltatory conduction (is faster) / description of ‘jumping’; 2 max
(b) Rise / fall in cholesterol concentration in cytoplasm / cell;
Reject references only to plasma concentrations;
Fall / rise in cholesterol receptors (in plasma membrane);
Leads to fall / rise in cholesterol / cholesterol returns to norm; 3
(c) (i) Mutation produces receptor with different shape / tertiary structure /
not specific to LDL;
So LDL will not bind to it and be absorbed / removed from the blood;
Do not penalise ‘active site’. 2
(ii) Endothelium / lining of artery torn / damaged;
Atheroma / plaque / underlying cells come into contact with blood;
Triggers blood clotting mechanism;
OR
Artery narrowed by plaque / atheroma;
May be blocked by clot from elsewhere; 2 max
(d) 2517;
Accept 2514 or 2511 if explanation refers to start / and stop codons. 1
(e) If recessive would inherit one allele from each parent; reject ‘gene’
Parents could be heterozygotes / carriers;
Parents / heterozygotes / carriers would not show the condition;
NB points 2 and 3 may appear in one linked sentence. 2
(f) 1003.;
Two marks for reason from below:
(As dominant,) both heterozygote and homozygote at risk;
(Heterozygotes 1 in 100 so) 1000 are heterozygous;
(Homozygotes 1 in 30000 so) .3 homozygous; 3 max
[15]
9. (a) (i) Same general structure as all amino acids; = 1 mark
Same general structure as all amino acids and answer making specific
reference
to amino/ NH2 group and carboxyl/ COOH group; 2
(ii) Not normally found in proteins/ polypeptides; 1
[Note: Alternative answers must fit with information provided
in passage]
Sir George Monoux Sixth Form College 4
