Question 1
The image shows some cells from onion epidermis.
(a) (i) Some structures in these onion cells are also found in human red blood cells.
Which row in the table is correct for human red blood cells?
(ii) The onion cells in the image are all epidermis cells.
What is the term for a collection of cells of the same type?
A organ
B organism
C system
D tissue
(b) The images show samples of red onion epidermis cells before and after being placed into a 5% sucrose solution for one hour
(i) Describe how to make 10 cm3 of a 5% sucrose solution from a 10% sucrose solution and pure water.
(ii) Explain the change in appearance of the onion cells shown in the images after being in the 5% sucrose solution for one hour.
▶️Answer/Explanation
1(a)(i) C (absent, present, absent)
A is incorrect because red blood cells have cytoplasm
B is incorrect because human red blood cells do not have a nucleus
D is incorrect because red blood cells do not have a cell wall
1(a)(ii) D (tissue)
A is incorrect because organs have more than one cell type
B is incorrect because organisms have more than one cell type
C is incorrect systems have more than one cell type
1(b)(i) A description that makes reference to the following:
• use a syringe / pipette / beaker / (measuring) cylinder / eq (1)
• mix 5 (cm3) of (10%) sucrose solution with 5 (cm3) water / eq (1)
1(b)(ii) An explanation that makes reference to three of the following:
• water leaves (the cells) / eq (1)
• by osmosis (1)
• from a high(er) water potential to a lower water potential / from higher water concentration to lower water concentration / from dilute solution to concentrated solution / eq (1)
• membrane detaches from cell wall / cell is flaccid / cytoplasm shrinks / cytoplasm volume decreases / cells are plasmolysed / eq (1)
Question 2
The diagram shows the structure of an insect pollinated flower.
(a) (i) Which part of the flower produces pollen?
A V
B X
C Y
D Z
(ii) Which part of the flower becomes a fruit?
A V
B W
C X
D Y
(b) The image shows a pollen grain produced by the plant.
(i) The diameter of the pollen grain in the image is 30mm.
The pollen grain has an actual diameter of 313µm.
Calculate the magnification of the pollen grain in the image.
Give your answer to the nearest whole number.
[1mm = 1000µm]
magnification = ×
(ii) State how the structure of the pollen grain is adapted to ensure insect pollination.
(c) Gardeners often reproduce plants by taking cuttings.
Explain why gardeners often reproduce plants by taking cuttings instead of growing the plants from seeds.
▶️Answer/Explanation
2(a)(i) C (Y)
A is incorrect because V is the ovary
B is incorrect because X is the stigma
D is incorrect because Z is the filament
2(a)(ii) A (V)
B is incorrect because W does not become a fruit
C is incorrect because X does not become a fruit
D is incorrect because Y does not become a fruit
2(b)(i) 96 (X) (3)
Stages of calculation:
• conversion of mm to μm (30 000)
• division of measured length by actual
• given to whole number
2(b)(ii) • spikes / hooks / sticky / eq (1)
2(c) An answer that makes reference to two of the following:
• asexual reproduction (1)
• cuttings are genetically identical / have same alleles / same genes / are clones / eq (1)
• faster / can be produced at any time of year / can be done from only one plant / no need to have insects / eq (1)
Question 3
The diagram shows a piece of apparatus used as a model for breathing.
The rubber sheet can be pulled down and pushed up to represent breathing.
(a) (i) Name the structure that the rubber sheet represents in a human.
(ii) Which row in the table gives the changes in volume and pressure inside the
glass jar when demonstrating inhalation?
(iii) Give two reasons why the apparatus does not give an accurate representation of human ventilation.
(b) The diagram shows the structure of an alveolus.
(i) Which of these is the order of the structures that air passes through, from the mouth to the alveolus, during inhalation?
A bronchiole ➔ bronchus ➔ trachea ➔ alveolus
B bronchus ➔ bronchiole ➜ trachea ➔ alveolus
C trachea ➔ bronchiole ➔ bronchus ➔ alveolus
D trachea ➔ bronchus ➔ bronchiole ➔ alveolus
(ii) The total surface area of the alveoli in lungs is very large.
A typical human lung has 480 000 000 alveoli.
Each alveolus has a surface area of 0.0040mm2.
Calculate the total surface area, in mm2, of the alveoli in one typical human lung.
Give your answer in standard form.
total surface area in one human lung = …………………………………………………………………………………mm2
(iii) Explain two ways that a single alveolus is adapted to maximise gas exchange.
(iv) Describe a simple laboratory experiment to investigate the effect of exercise on the rate of carbon dioxide release from a human.
▶️Answer/Explanation
3(a)(i) • diaphragm (1) 1
3(a)(ii) C (increases decreases)
A is incorrect because the volume increases
B is incorrect because the volume increases
D is incorrect because the pressure decreases
3(a)(iii) A description that makes reference to two of the following:
• jar cannot expand / cannot change shape / jar is rigid / ribcage can move / thorax can move / eq (1)
• no intercostal muscles / no ribs / eq (1)
• no pleural membrane / no pleural fluid / balloons do not touch the sides of jar / eq (1)
3(b)(i) D (trachea bronchus bronchiole alveolus)
A is incorrect because bronchiole is not first
B is incorrect because bronchus is not first
C is incorrect because bronchiole is not second
3(b)(ii) • 1.9 x 106
3(b)(iii) An explanation that makes reference to four of the following:
(Mark in pairs)
• one cell thick layer (for alveoli or capillaries) / thin layer / thin membrane / eq (1)
• short diffusion path / rapid diffusion / easy diffusion / eq (1)
• blood supply / capillaries / blood vessels / blood / eq (1)
• maintains concentration gradient / maintains diffusion gradient / steep gradient / eq (1)
• moisture / fluid / eq (1)
• dissolves gases / allows gases to pass through (alveolar) wall / eq (1)
3(b)(iv) A description that makes reference to three of the following:
• use of limewater / hydrogen carbonate indicator (1)
• measure time taken (for limewater) to go cloudy / measure time taken (for indicator) to change / eq (1)
• measure with and without exercise / measure before and after exercise / have one person exercising and one resting / eq (1)
• same volume of limewater / same volume of indicator / same temperature of room / same age / sex / fitness of person / eq (1)
• repeats / calculate mean / eq (1)
Question 4
A student uses this method to investigate the effect of temperature on the digestion of starch by the enzyme amylase.
• place 5 cm3 of starch solution into a test tube
• place 1 cm3 of amylase solution into a second test tube
• place both the test tubes into a water bath at 10 ºC for 10minutes
• then pour the amylase solution into the starch solution and mix
• test a sample of the mixture for the presence of starch every five minutes until no more starch is present
• repeat at temperatures of 20 ºC, 30 ºC, 40 ºC and 50 ºC.
The investigation is repeated two more times at each temperature.
(a) (i) What is produced when starch is digested by amylase?
A amino acids
B glycerol
C maltose
D sucrose
(ii) Which of these parts of the human alimentary canal produce amylase?
1 colon
2 pancreas
3 salivary gland
A 1 and 2 only
B 1, 2 and 3
C 2 and 3 only
D 3 only
(b) (i) State why the test tubes are placed in a water bath for 10minutes before mixing the contents.
(ii) Describe how the student could test a sample of the mixture for starch.
(c) The table shows the results of the student’s investigation.
(i) Calculate the mean time taken for all starch to be digested at 30 ºC.
Give your answer to two significant figures.
mean time = …………………………………………………….. minutes
(ii) Explain the effect of increasing the temperature from 10 ºC to 40 ºC on the time taken for all the starch to be digested.
(iii) Explain why the starch was not digested when the temperature was 50 ºC.
(iv) Explain how the student could modify the investigation to give a more accurate measure of the temperature at which the amylase activity is fastest.
▶️Answer/Explanation
4 (a)(i) C (maltose)
A is incorrect because amino acids are not produced
B is incorrect because glycerol is not produced
D is incorrect because sucrose is not produced
4 (a)(ii) C (2 and 3 only)
A is incorrect because the colon does not produce amylase
B is incorrect because the colon does not produce amylase
D is incorrect because the pancreas also produces amylase
4 (b)(i) • to reach temperature / bring to temperature / make sure at 10 oC / equilibrate / warm up / eq (1)
4 (b)(ii) • add iodine (solution) (1)
• black / (dark) blue (colour) (1)
4 (c) (i) • 23 (2)
4(c)(ii) An explanation that makes reference to two of the following:
• increased (kinetic) energy (1)
• faster movement (of enzyme and substrate) / eq (1)
• more collisions / greater rate of collisions / more E/S complexes / eq (1)
• reaches optimum temperature for enzymes (1)
4(c)(iii) An explanation that makes reference to two of the following:
• enzyme denatures / amylase denatures (1)
• active site changes shape / enzyme is not complementary to substrate / enzyme changes shape / eq (1)
• substrate / starch no longer binds / fits / eq (1)
4(c)(iv) An explanation that makes reference to two of the following:
1. use smaller temperature intervals / / use 5 oC intervals / use 1 oC intervals / eq (1)
2. between 30 and 40 / between 30 and 50 / between 40 and 50 / the rate may be faster at temperatures above or below 40 / optimal may not be at 40 / eq
3. use smaller time intervals / eq (1) 4. as similar recorded times may actually be different / eq (1)
Question 5
The diagram shows part of a food web for the Arctic Ocean.
(a) (i) Phytoplankton are protoctists that photosynthesise.
Which of the following features do phytoplankton share with plants?
1 chitin cell wall
2 chloroplast
3 nucleus
A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 2 only
(ii) Name two organisms in this food web that can feed as tertiary consumers.
(iii) Draw the food chain with the most trophic levels in this food web.
(b) Scientists measure the changes in the biomasses of phytoplankton and zooplankton in one year.
(i) During a month in spring, the scientists found that the biomass of phytoplankton in the water increased from 1.2 mgperdm3 to 12.6mgperdm3.
Calculate the percentage increase of these phytoplankton in this month.
percentage increase = …………………………………………………….%
(ii) During the year, the scientists also measured the change in the number of hours of light each day and the change in nitrate concentration in the water near the surface of the ocean.
The graph shows their results.
Discuss the reasons for the changes in the biomasses of phytoplankton and zooplankton during the year.
5(a)(i) C (2 and 3 only)
A is incorrect because chitin is not present in either
B is incorrect because chitin is not present in either
D is incorrect because both have chloroplasts
▶️Answer/Explanation
5(a)(ii) any two of :
(polar) bear / seal / (grey) whale / predatory fish (1)
5(a)(iii) phytoplankton → zooplankton → plankton-eating fish → predatory fish → seal → (polar) bear (2)
5(b)(i) • 950% (2)
Example of calculation:
correct increase (12.6 – 1.2 = 11.4)
correct percentage calculation
5(b)(ii) An answer that makes reference to five of the following points:
1. phytoplankton / zooplankton (biomass) is low in winter / eq (1) 2. phytoplankton mass increases in (mid) spring / as light increases, phytoplankton (biomass) increases / eq (1)
3. (phytoplankton increase in late spring) due to photosynthesis / eq (1)
4. (photosynthesis) produces glucose / sugar / carbohydrates / eq (1)
5. zooplankton increase (when phytoplankton is high) as more food / more phytoplankton to eat / eq (1)
6. phytoplankton decreases when consumed by (many) zooplankton / increases when few zooplankton eating them / eq (1)
7. (when phytoplankton increase) nitrates decrease as phytoplankton absorb them / use them / eq (1)
8. nitrates used to make amino acids / protein / chlorophyll / eq (1)
9. phytoplankton biomass limited by nitrates / light / zooplankton population / eq (1)
Question 6
A reflex is a rapid response to a stimulus.
(a) The withdrawal of a hand when a finger touches a hot object is an example of a reflex.
Describe the pathway of a nerve impulse in the reflex arc involved in this response.
(b) The photograph shows an African land snail.
(Source: © MYN / JORIS VAN ALPHEN / NATURE PICTURE LIBRARY / SCIENCE PHOTO LIBRARY)
When an African land snail is touched on its eyestalk, the snail goes back into its shell. The snail then remains in its shell for a period of time.
A student investigates the effect that repeatedly touching the eyestalk has on the time the snail remains in its shell.
This is the student’s method.
• gently touch the eyestalk of a snail with a cottonwool bud so that the snail goes back into its shell
• measure the time the snail remains in its shell
• after the snail has come back out of its shell, touch the eyestalk again so that the snail goes back into its shell again
• measure the time the snail remains in its shell
• repeat the stimulus six more times
The student’s results are shown in the table.
(i) Plot a graph to show the effect of stimulus number on the time the snail remains in its shell.
Join your points with ruled, straight lines.
(ii) Describe the effect of increasing stimulus number on the time the snail remains in its shell.
(iii) Suggest a benefit to the snail of the difference in response to the repeated stimulus.
▶️Answer/Explanation
6(a) A description that makes reference to four of the following points:
1. receptor (generates impulse) / eq (1)
2. (impulse) passes along sensory neurone (to relay / motor neurone / to CNS / spinal cord) (1)
3. (sensory / relay / CNS / spinal cord) to motor neurone (1)
4. to muscle / effector (1)
5. crosses synapses (1)
6. (using) neurotransmitters (1)
6(b)(i) S: linear scales for both axes (1)
L: straight line joining points (1)
A: axes correct way round (1)
A: axes both labelled, and with units on y axis (1)
P: points plotted correctly (1)
6(b)(ii) A description that makes reference to the following points:
• (time) decreases / eq (1)
• falls (more steeply) after 5 / from 6 touches / small decrease until 5 or 6 / eq (1)
6(b)(iii) An explanation that makes reference to two of the following points:
• (few stimuli) could represent danger / allow escape / escapes predator / snail not eaten / helps snail survive / eq (1)
• (repeated stimuli) suggests no danger / no longer represents danger / snail recognises there is no threat / has learnt that there is no danger / eq (1)
• (when not staying in shell) snail can eat for longer / can continue moving / does not waste energy / eq (1)
Question 7
Coronary heart disease (CHD) is caused by damage to the walls of the coronary artery.
(a) (i) Explain two differences between the structure of the wall of an artery and the wall of a vein.
(ii) The diagram shows a cross-section of a coronary artery from a healthy person and from a person with CHD.
The heart needs to respond to extra demands during exercise.
Explain why, during exercise, the heart of a person with CHD would not respond as efficiently as the heart of a healthy person.
(b) Genetics and smoking are two risk factors for CHD.
The alleles of some genes increase the risk of developing CHD in people. These are known as risk factor alleles.
Scientists compared the relative risk of developing CHD in people with different numbers of these risk factor alleles.
The scientists also compared the risk of developing CHD for non-smokers and smokers.
The graph shows the scientists’ results.
(i) Give one risk factor for CHD, other than genetics and smoking.
(ii) Comment on the relationship between the number of risk factor alleles and smoking on the risk of developing CHD.
Use data from the graph to help your answer.
▶️Answer/Explanation
7(a)(i) An explanation that makes reference to four of the following points:
(mark in pairs)
• thick layer of elastic / (more) elastic / eq (1)
• as blood pressure is higher / for wall to recoil / to expand / wall can stretch / smooths blood flow / eq (1)
• thick layer of muscle / (more) muscle / eq (1)
• control blood flow / eq (1)
• no valves (1)
• as blood pressure is sufficient to prevent backflow / no need to prevent backflow / eq (1)
7(a)(ii) An explanation that makes reference to three of the following points:
• artery has blockage / less blood can flow / artery is narrow / artery has narrow lumen / eq (1)
• less oxygen (to heart muscle) / eq (1)
• less (aerobic) respiration / more anaerobic respiration / eq (1)
• less energy / less ATP / eq (1)
• so heart unable to beat faster during exercise / eq (1)
7(b)(i) An answer that makes reference to one of the following points:
• high cholesterol / high fat diet / eq (1)
• lack of exercise / eq (1)
• stress / eq (1)
• high salt (diet) (1)
• high BMI / obesity / eq (1)
• diabetes (1)
• age / eq (1)
• sex (1)
• high blood pressure (1)
7 (b)(ii) An answer that makes reference to five of the following points:
1. smoking increases risk of CHD (in all groups) / eq (1)
2. more alleles (always) increases risk (of CHD) / eq (1)
3. highest risk is for smokers with high number of alleles / lowest risk is for non-smokers with few alleles / eq (1)
4. biggest increase from smoking is for those with few risk alleles / lower increase from smoking with medium or high allele group / eq (1)
5. smokers with few alleles have same risk of CHD than non-smokers with many alleles / eq (1)
6. credit manipulated data, e.g. smoking increases risk by 1 for low allele group (1)
7. carbon monoxide (in cigarette smoke) (causes CHD) (1)
8. smoking causes plaques / cholesterol build up / blocks coronary artery / eq (1)
9. no mention of group size in data / may be low sample size / eq (1)
10. no mention of age / sex / diet / other health issues / frequency of smoking / eq (1)
Question 8
Lactose is the sugar found in milk.
The lactose needs to be digested in humans by an enzyme called lactase so the products can be absorbed.
All human babies produce lactase in their intestines.
People who are lactose intolerant stop producing lactase and are unable to digest lactose sugar as adults.
Lactose intolerance is a genetic condition caused by a recessive allele, d.
The ability to digest lactose is caused by a dominant allele, D.
(a) (i) The diagram shows a family pedigree.
Use a genetic diagram to determine the probability of individuals 4 and 5 having a child with lactose intolerance.
probability =
(ii) People with lactose intolerance often get diarrhoea (production of faeces with high water content) if they drink milk.
Suggest why people who cannot digest lactose get diarrhoea if they drink milk.
(iii) Milk is a nutritious substance that provides several food groups.
In areas of the world where milk is a main part of the diet, fewer people are lactose intolerant.
Explain how natural selection has resulted in fewer people being lactose intolerant in areas of the world where milk is a main part of the diet throughout their lives.
(b) Milk can be used to produce yoghurt.
The diagram shows a fermenter that can be used to produce yoghurt in industry.
(i) Explain the role of the stirrer in the fermenter.
(ii) Explain the role of the water jacket in the fermenter.
▶️Answer/Explanation
8(a)(i) An answer that makes reference to the following points:
• correct genotypes of parents (Dd, dd) (1)
• correct gametes (D or d, d (or d)) (1)
• correct genotypes of offspring (Dd, dd)
• correct probability of 0.5 / 50 % 1⁄2 / eq (1)
8(a)(ii) An answer that makes reference to two of the following points:
• less water absorbed (into blood) (1)
• by colon / intestine (1)
• as sugar / lactose is not absorbed (1)
• (as lactose) affects osmosis / lowers water potential / eq (1)
• (lactose could cause) bacteria to grow / bacteria break down lactose / eq (1)
8(a)(iii) An explanation that makes reference to four of the following points:
• mutation (occurred) (1)
• creating (genetic) variation (1)
• people with lactose tolerance (DD or Dd) can drink milk / did not get diarrhoea / can gain extra nutrients / were able to compete better / survived / had a selective advantage / eq (1)
• reproduced (more) / produced offspring / eq (1)
• pass on allele / gene / mutation / eq (1)
8(b)(i) An explanation that makes reference to the following points:
• mixes the contents / spreads nutrients / maintains even consistency / prevent settling / eq (1)
• maintain even temperature / prevent hot spots / maintain an even pH / eq (1)
8(b)(ii) An explanation that makes reference to two of the following points:
• removes heat / cools the fermenter / eq (1)
• to maintain optimal temperature (1)
• prevent enzymes denaturing / prevent death of bacteria / eq (1)
Question 9
Transgenic varieties of tomato plants have been produced that can photosynthesise more efficiently than natural varieties.
(a) To make the transgenic tomato plants, a gene is inserted into a vector that is then placed into tomato plant cells.
Describe how a recombinant vector containing a gene can be produced.
(b) The graph shows the effect of temperature on the rate of photosynthesis of tomato plants at two different light intensities.
Explain the effect of temperature on the rate of photosynthesis of the tomato plants at high and low light intensity.
(c) The diagram shows a sustainable glasshouse system that is used in the United Kingdom to grow tomato plants throughout the year.
The glasshouse has artificial lighting and heating powered by electricity from a wood-burning power station.
Carbon dioxide is pumped from the power station into the glasshouse.
Discuss the advantages of growing tomato plants in this glasshouse system.
In your answer include the benefits for farmers and for the environment.
▶️Answer/Explanation
9(a) A description that makes reference to the following points:
• plasmid (used) (1)
• restriction enzyme used to cut out gene / cut plasmid / cut DNA / eq (1)
• ligase used to insert gene into plasmid / stick DNA / glue DNA / stick gene with DNA / eq (1)
9(b) An explanation that makes reference to three of the following points:
• increasing temperature increases the rate of photosynthesis / eq (1)
• because particles have more (kinetic) energy / more frequent collisions / there is more enzyme activity / eq (1)
• (at low light intensity rate levels off) so light is limiting / eq (1)
• (at high light intensity) carbon dioxide limits rate / not enough carbon dioxide / eq (1)
9(c) An answer that makes reference to five of the following points:
1. light, carbon dioxide and (warm) temperature supplied / eq (1)
2. so no factors for photosynthesis are limiting / all factors present for photosynthesis / there is more photosynthesis / eq (1)
3. so high yield / fast production / (to give high profit) / more tomatoes / eq (1)
4. no need to buy carbon dioxide / no need to buy electricity / wood is cheaper than fossil fuel / wood cheaper than buying electricity / eq (1)
5. tomatoes protected from pests / disease / frost / cold / bad weather / eq (1)
6. wood is renewable (energy) / eq (1)
7. less use of fossil fuel / eq (1)
8. carbon dioxide not released into atmosphere / eq (1)
9. less greenhouse effect / less climate change / less ice cap melting / eq (1)
10.less release of sulfur dioxide / less acid rain / eq (1)
Question 10
The photograph shows a scarecrow in a crop field.
Scarecrows are models of humans placed into fields to stop birds eating crops.
Design an investigation to find out if changing the colour of the clothes the scarecrow is wearing alters how effective the scarecrow is at stopping birds eating crops.
Your answer should include experimental details and be written in full sentences.
▶️Answer/Explanation
10 An answer that makes reference to six of the following points:
• C change colour / eq (1)
• O type of scarecrow / size of scarecrow / use same scarecrow / type of fabric / size of clothing / eq (1)
• R repeat / eq (1)
• M1 count number of birds / mass of crop / amount of birds / number of plants eaten / yield of crop / eq (1)
• M2 stated period of time / eq (1)
• S1 same time of year / season / area of field / position (of scarecrow) in field / weather / time of day / wind speed / light / water / humidity / temperature / eq (1)
• S2 same crop / quality of crop / (starting) number of crops / fertiliser / pesticides / soil quality / soil pH / eq (1)