Question 1
The diagram shows part of a food web from an oak woodland.
(a) (i) Which is the producer in this food web?
A beetle
B deer
C oak tree
D tick
(ii) Draw a food chain, from this web, that includes the mouse and contains four trophic levels.
(iii) Which one of these organisms is in two different trophic levels in this food web?
A ant
B blue jay
C caterpillar
D mouse
(b) A tick is a small spider-like organism that bites and then takes in blood from the mammals as it feeds.
This is a magnified image of a tick.
(i) The actual length of the tick, as shown by line A-B, is 3.5 mm.
Calculate the magnification of the image of the tick.
magnification = ×………………
(ii) The tick absorbs substances from the mammal’s blood it has taken in.
Give the function of two named substances absorbed by the tick.
substance 1
substance 2
(iii) Ticks can pass diseases between organisms.
Suggest how ticks can pass diseases from one organism to another.
▶️Answer/Explanation
1(a)(i) C (oak tree)
A is not the answer as beetle is not the producer
B is not the answer as deer is not the producer
D is not the answer as tick is not the producer
1(a)(ii) oak / tree → caterpillar → mouse → tick (2)
1(a)(iii) D (mouse)
A is not correct as the ant is not at two levels
B is not correct as the blue jay is not at two levels
C is not correct as the caterpillar is not at two levels
1(b)(i) Calculation method not marking points
Measurement of line 10.4 cm / 104 mm
Measurement of line ÷ 3.5mm = 29-30 (2)
Correct answer = 2 marks
1(b)(ii) An explanation makes reference to four of the following:
• substance 1 (1)
• required for function 1 (1)
• substance 2 (1)
• required for function 2 (1)
1(b)(iii) An answer that makes reference to two of the following:
• tick picks up / bites / sucks up / absorbs blood from infected animal / animal with disease / eq (1)
• bacteria / virus / pathogen / eq (1)
• feed / bite / (new / uninfected ) other animal /eq (1)
Question 2
The diagram shows a flower with some structures labelled.
(a) (i) Which structure is the style?
A P
B Q
C S
D T
(ii) Which structure releases pollen?
A P
B R
C T
D U
(iii) On which structure do the pollen grains germinate?
A P
B R
C S
D U
(b) This flower is insect-pollinated.
Describe how structures P, R and T would be different in a wind-pollinated flower.
P
R
T
(c) Flowering plants can reproduce asexually.
(i) Give an example of a natural method of asexual reproduction in plants.
(ii) Give an example of an artificial method of asexual reproduction in plants.
1
2
3
(e) A farmer has two varieties of a plant species.
One variety has a red flower colour and no scent.
The other variety has a white flower colour and a perfumed scent.
The farmer wants to produce a variety that has the red flower colour and the perfumed scent.
Explain how the farmer could achieve this.
▶️Answer/Explanation
2(a)(i) B (Q)
A is not the answer as P is not the style
C is not the answer as S is not the style
D is not the answer as T is not the style
2(a)(ii) D (U)
A is not the answer as P does not release pollen
B is not the answer as R does not release pollen
C is not the answer as T does not release pollen
2(a)(iii) A (P)
B is not correct as pollen grains do not germinate on R
C is not correct as pollen grains do not germinate on S
D is not correct as pollen grains do not germinate on U
2(b) A description that makes reference to the following:
• P feathery / large surface area / outside flower /exposed / eq (1)
• R absent / smaller / not coloured / green / eq (1)
• T longer / hinged / outside flower / exposed / eq (1)
2(c)(i) • runners / bulbs / corms/ tubers / rhizomes /eq (1)
2(c)(ii) • cuttings / grafting / layering / tissue culture / micropropagation / eq (1)
2(d) An answer that makes reference to the following:
Allow two / three in one numbered line
• no gametes produced in asexual / no meiosis in asexual / gametes produced in sexual / meiosis in sexual / one parent cell (1)
• no fusion or fertilisation in asexual / present in sexual (1)
• offspring are clones / show no genetic variation in asexual / genetic variation in sexual /eq (1)
• asexual faster / shorter time / sexual slower / longer time / eq (1)
2(e) An explanation makes reference to three of the following:
• selective breeding / artificial selection (1)
• cross red (flower)/ unscented (flower) with white (flower) / scented (flower)/ eq (1)
• select / breed / offspring with red and scent /eq (1)
• repeat / for many generations eq (1)
Question 3
The passage describes the process used to produce yoghurt.
Complete the passage by writing a suitable word or words in each blank space.
Yoghurt is made by heating ……………………………………………………. to a high temperature.
This heating process is known as ……………………………………………………. .
This ensures that bacteria present in the liquid are ……………………………………………………. .
The liquid is then cooled to between 40 oC and 46 oC.
A type of bacteria called ……………………………………………………. is then added.
These bacteria use a sugar called ……………………………………………………. for
……………………………………………………. respiration.
The pH of the yoghurt decreases because this respiration produces a substance called
……………………………………………………. .
▶️Answer/Explanation
• milk (1)
• pasteurisation / sterilisation (1)
• killed (1)
• Lactobacillus / Streptococcus (1)
• lactose (1)
• anaerobic (1)
• lactic acid / lactate (1)
Question 4
A respirometer is a simple apparatus that can be used to measure the rate of respiration in small organisms.
A student uses the respirometer to investigate the rate of respiration in some germinating seeds.
(a) Give the balanced chemical symbol equation for aerobic respiration.
(b) The student measures the rate of respiration of 10g of germinating seeds at 20 OC.
They then repeat this with another sample of 10g of germinating seeds at 30 OC.
The rate of respiration can be measured by recording the distance, in mm, the bubble of coloured liquid moves on the scale in one minute.
They measure the rate three times at each temperature.
(i) Explain why carbon dioxide needs to be absorbed by the soda lime when measuring the rate of aerobic respiration.
(ii) State how the student could have changed the temperature in this investigation.
(c) The table shows the student’s results.
(i) Calculate the mean distance moved by the bubble at 30 OC.
mean distance = ……………………………………………………. mm
(ii) Explain the effect of increasing the temperature on the movement of the bubble.
▶️Answer/Explanation
4(a) C6H12O6 + 6O2 6CO2 + 6H2O (2)
4(b)(i) An explanation that makes reference to two of the following
• bubble would not move / CO2 also moves / shifts bubble /eq (1)
• carbon dioxide is produced / released /eq (1)
• (only) oxygen consumption measured / eq (1)
4(b)(ii) • water bath / eq (1)
4(c)(i) Calculation method not marking points
22 + 25 + 24 = 71
71 ÷ 3
= 24 (2)
4(c)(ii) An explanation that makes reference to three of the following:
• increases (kinetic) energy of molecules / molecules move faster / eq (1)
• collide more frequently / form more enzyme substrate complexes/eq (1)
• respiration (rate) increases / eq (1)
• more oxygen consumed / oxygen used faster/ eq (1)
• ref to/ nearer to optimum temperature for enzymes / eq (1)
Question 5
(a) Increased release of greenhouse gases are a threat to many ecosystems.
(i) Which of these are greenhouse gases?
1 CFCs
2 methane
3 oxygen
4 water vapour
1 and 2 only
B 1, 2 and 3 only
C 1, 2 and 4 only
D all of them
(ii) Explain what is meant by the term greenhouse effect.
(b) The graph shows the mass of greenhouse gases emitted from four sources in the United Kingdom from 1990 to 2020.
(i) Calculate the percentage of the total greenhouse gases emitted that came from energy production in 2020.
percentage = …………………………………………………….. %
(ii) Comment on the changes in the four sources of greenhouse gases from 1990 to 2020.
Use the information in the graph and your own knowledge to support your answer.
▶️Answer/Explanation
5(a)(i) C (1,2 and 4 only)
A is not correct as water vapour is a greenhouse gas
B is not correct as oxygen is not a greenhouse gas and water vapour is a greenhouse gas
D is not correct as oxygen is not a greenhouse gas
5(a)(ii) An explanation that makes reference to the following:
• IR / long wave radiation is absorbed / traps IR / long wave radiation / traps heat / prevents heat escaping / eq (1)
• (so) increases (global) temperature / earth warms / global warming /eq (1)
5(b)(i) Calculation method not marking points
readings = agriculture 50, energy 110, business 118, transport 175
adding together 50 + 110 + 118+ 175 = 453
% energy = (110 ÷ 453) × 100
= 24% (3) allow range 23.9-24.9
5(b)(ii) An answer that makes reference to five of the following:
1. overall emissions fall / less mass / eq (1)
2. energy most in 1990 / falls the most / (large) fall in energy /eq(1)
3. energy now generated by wind / solar / less from coal / gas power stations / less burning of fossil fuels/ eq (1)
4. transport increases / increases then falls / transport falls from 2009 / 2010 / eq (1)
5. more cars / more emissions / (then) change to / more electric / hybrid cars / less travelling to work / eq (1)
6. agriculture drops / eq (1)
7. less cattle farmed / less methane released / eq (1)
8. business little change / drops slightly / eq (1)
Question 6
A student uses this apparatus to investigate the effect of light intensity on the rate of photosynthesis in pondweed.
This is the student’s method.
• put a cut piece of pondweed in a beaker of water
• put a lamp 12 cm from the beaker
• count the number of bubbles of gas released from the cut end of the pondweed in one minute
• repeat this count for two more one-minute periods
The student repeats the method, moving the lamp 2 cm nearer the beaker each time.
(a) (i) Which gas is released by the plant during photosynthesis?
A carbon dioxide
B oxygen
C methane
D nitrogen
(ii) Which of these is the site of photosynthesis in a plant cell?
A chloroplast
B mitochondrion
C nucleus
D ribosome
(iii) Give one abiotic variable the student should control in this investigation.
(b) The table shows the student’s results
(i) Plot a line graph to show the relationship between the distance of the lamp from the beaker and the mean number of bubbles released.
Use a ruler to join your points with straight lines.
(ii) Explain the effect of increasing the distance of the lamp from the beaker on the mean number of bubbles released per minute.
▶️Answer/Explanation
6(a)(i) B (oxygen)
A is not the answer as carbon dioxide is not released
C is not the answer as methane is not released
D is not the answer as nitrogen is not released
6(a)(ii) A (chloroplast)
B mitochondrion is not the site of photosynthesis
C nucleus is not the site of photosynthesis
D ribosome is not the site of photosynthesis
6(a)(iii) • temperature / carbon dioxide concentration / pH / background light / same bulb/ lamp / time period / eq (1)
6(b)(i) An answer that refers to the following
• scale linear and plot half grid on y (1)
• lines straight and through points (1)
• axis correct way around (distance on x axis) (1)
• points correctly plotted (1)
• units distance from lamp in cm and bubbles per minute (1)
6(b)(ii) An explanation that refers to three of the following
• as distance increases rate falls / fewer bubbles / eq (1)
• as light intensity reduces / less light energy / light becomes limiting factor (1)
• slower rate of / less photosynthesis (1)
• less oxygen released / fewer oxygen bubbles released (1)
Question 7
(a) Human blood contains red blood cells and white blood cells.
Give three differences in structure between red blood cells and white blood cells.
(b) Scientists collect data from men and women living at different altitudes.
The scientists determine
• the mean mass of haemoglobin in one litre of blood
• the mean number of red blood cells in one litre of blood
The table gives the scientists’ results.
(i) The blood volume of a woman living at an altitude of 1890m is 4.3 litres.
Calculate the total number of red blood cells in this person.
Give your answer in standard form.
number of red blood cells = …………………………………………….
(ii) Calculate the percentage difference in mean mass of haemoglobin in 1 litre of blood in men living at 2270m compared with men living at sea level.
(iii) Discuss the relationship between altitude and mean mass of haemoglobin in 1 litre of blood and the number of red cells in 1 litre of blood in men and women.
Use the data in the table and your own knowledge in your answer.
▶️Answer/Explanation
7(a) An answer that refers to three of the following
• red cell has no nucleus eq (1)
• red cell biconcave disc / eq (1)
• red cell small(er) /eq (1)
• red cell contains haemoglobin / eq (1)
7(b)(i) Calculation method not marking points
4.3 × 5.2
= 22.36
22.4 × 10 12
2.2 × 10 13 (3)
7(b)(ii) Calculation method not marking points
151 – 148 = 3
(3÷ 148) × 100
= 2.03% (2)
7(b)(iii) An answer that makes reference to five of the following:
1. large numbers / study / reliable results / eq (1)
2. fewer people in study / lower numbers at altitude than sea level /eq(1)
3. more women than men / eq (1)
4. no information on age /health / body mass / eq (1)
5. Hb increases from 0 to 1890 / from 0 to 2270 / with altitude eq (1)
6. (as) more red cells (produced) (at 1890) (at 2270) / eq (1)
7. as less partial pressure of oxygen / less (availability of) oxygen / eq (1)
8. to enable oxygen transport / uptake / aerobic respiration / eq (1)
9. little change in Hb / (slight) reduction from 1890 to 2270 / eq (1)
10.as small(er) increase in altitude / eq (1)
11. drop in red cells from 1890 to 2270 / eq (1)
12. men have more Hb/ more red cells (at every altitude) than women / eq (1)
Question 8
Cystic fibrosis (CF) is a condition that affects the mucus produced in the lungs and in other organs.
The condition is caused by a recessive allele.
(a) State what is meant by a recessive allele.
(b) The diagram below shows a family pedigree.
Some people in the family have CF.
(i) Use the pedigree to determine the genotypes of individuals A, B and C.
(ii) Individuals E and F have a third child.
Draw a genetic diagram to show the genotypes of E and F, the gametes they produce and the possible genotypes and phenotypes of the offspring.
(c) The gene for cystic fibrosis affects many different body systems including the digestive system and the reproductive system.
(i) The mucus that is produced in the pancreas is much thicker and blocks the pancreatic duct.
Explain the effects this would have on human digestion.
(ii) Cystic fibrosis can result in the production of thick mucus which builds up in the cervix.
Explain the effect this will have on reproduction.
▶️Answer/Explanation
8(a) • an allele that is only expressed in the homozygote / only in phenotype of homozygote / only shown in (phenotype) if two copies/ needs two copies to be expressed / not expressed in the heterozygote / not
expressed if dominant allele present / not always expressed / eq (1)
8(b)(i) An answer that includes
A Ff / heterozygous (1)
B Ff / heterozygous (1)
C ff / homozygous recessive (1)
8(b)(ii) An answer that includes the following:
• Ff and Ff (1)
• F and f (1)
• FF Unaffected Ff Unaffected (x2) (Ff) ff affected 1 / allow correct phenotype ratio (1)
8(c)(i) An explanation that refers to three of the following
• pancreas produces / releases amylase / proteases / lipases / eq (1)
• no / less digestion of starch to maltose /eq (1)
• no / less digestion of proteins to amino acids / (poly)peptides to amino acids /eq (1)
• no / less digestion of lipid to fatty acids and glycerol (1)
• less absorption of smaller molecules / soluble molecules / amino acids / glucose / fatty acids / eq (1)
8(c)(ii) An explanation that refers to two of the following
• reduce likelihood of pregnancy / less likely to conceive / eq (1)
• sperm / semen cannot enter fallopian tube / oviduct 1)
• fertilisation less likely / no fertilisation / fusion (of gametes) (1)
Question 9
Students investigate the effect of mineral ions on plant growth.
They use four solutions A, B, C and D.
• A is a complete mineral solution that contains all of the mineral ions that a plant needs to grow normally
• B is a complete mineral solution without nitrate ions
• C is a complete mineral solution without magnesium ions
• D is a complete mineral solution without iron ions
The plant they use is duckweed, which grows on the surface of water
This is the students’ method.
• place each of the four solutions (A, B, C and D) into separate jars
• float five plants of duckweed in each jar
• use plants with the same number of leaves, are the same size and are healthy
• cover each jar with plastic film
• put the jars containing the plants in sunlight
• after four weeks count the total number of leaves in each jar
• make a note of the size and colour of the leaves in each jar
(a) (i) State two variables the students kept constant in their experiment.
(ii) Explain why the students used complete mineral solution rather than distilled water to compare the effects of lacking a mineral ion.
(iii) Explain why the jars are kept in sunlight.
(iv) State the independent variable in this investigation.
(b) The students record the total number of leaves in each jar.
They classify the leaf size as large, medium and small.
They record leaf colour as how green the leaves were between 0 for white to 5 for dark green.
The students’ results are shown in the table.
(i) Some of the observations such as number of leaves are quantitative and some such as leaf size are qualitative.
Give the difference between quantitative and qualitative results.
(ii) Comment on the students’ results.
In your answer you should use data from the table and your own knowledge.
▶️Answer/Explanation
9(a)(i) An answer that makes reference to two of the following:
• sunlight / light / eq (1)
• volume /mass of solution / eq (1)
• number of plants / number of leaves / size of leaves / size of plant /health of leaves (at start)/ eq(1)
• same species / use duckweed /eq (1)
• time / duration/ eq (1)
• all jars covered /eq (1)
9(a)(ii) An explanation that makes reference to two of the following:
• it (complete solution) (contains all minerals) so produces normal growth / ideal growth / eq (1)
• distilled water contains no minerals / plant would be lacking all minerals / would not grow normally /eq (1)
• so any difference in growth due to missing one mineral / eq (1)
9(a)(iii) An explanation that makes reference to two of the following:
• photosynthesis /eq (1)
• to produce glucose (for respiration) / eq (1)
• for growth / to allow normal growth / eq (1)
9(a)(iv) • mineral that is missing / absent from solution / minerals present / composition of solution / solution / eq (1)
9(b)(i) • (quantitative / number of leaves) uses number / is measured / counted / and (qualitative / size of leaf ) is a type / category / uses words / observed / subjective /opinion / eq (1)
9(b)(ii) An answer that makes reference to 6 of the following:
1. complete / no minerals lacking/ A have most leaves / largest leaves / eq(1)
2. complete / no minerals lacking / A have dark green / greenest leaves /eq (1)
3. minus nitrate / B have few / least / smaller / smallest leaves / less green /yellow/ eq (1)
4. nitrate required for amino acid / protein / chlorophyll / chloroplasts / nitrate required for growth /eq (1)
5. minus magnesium / C have few / smaller / less green / yellow / eq (1)
6. magnesium required for chlorophyll / chloroplasts / photosynthesis /eq(1)
7. minus iron / D have few / smaller leaves / less green / least green / yellow / eq (1)
8. iron required for chlorophyll /chloroplasts / photosynthesis / eq (1)
9. Not repeated / not reliable / few plants used / eq (1)
Question 10
Carbon dioxide can be added to a glasshouse to increase the yield of a crop plant.
Design an investigation to find the carbon dioxide concentration needed for maximum crop yield.
Include experimental details in your answer and write in full sentences.
▶️Answer/Explanation
10 An answer that makes reference to six of the following:
C use glasshouses with three or more concentrations / levels / amounts of carbon dioxide / eq (1)
O use crop plants of same species eq/ (1) R repeat each concentration /eq (1)
M1 measure mass / kg / amount of seeds / number of leaves / fruit / size (of leaves) / eq (1)
M2 after stated time / eq (1) S1 temperature / (sun)light / same season / eq (1)
S2 same soil / water / humidity / fertiliser / minerals/ pH/ eq (1)