Question 1
The diagram shows a flower from an apple tree, with some structures labelled.
(a) (i) This apple tree is able to self-pollinate. Which is the correct transfer of pollen during pollination?
A P to Q
B P to T
C V to P
D V to S
(ii) Which structure does the pollen tube grow down?
A Q
B U
C V
D R
(iii) Which structure develops into the seed?
A P
B S
C T
D V
(b) The flower from an apple tree is insect‐pollinated.
Give three differences between the structure of this apple flower and the structure of a wind‐pollinated flower such as grass.
(c) The seeds of many plants are surrounded by sweet‐tasting fruit.
Suggest how this enables the plants to spread their seeds.
▶️Answer/Explanation
1(a)(i) The only correct answer is
C V to P as V is anther and P is stigma
A is not the answer as P is not anther and Q is not stigma
B is not the answer as P is not anther and T is not stigma
D is not the answer as it S not stigma
1(a)(ii) The only correct answer is
A as Q is the style
B is not correct as U is the filament
C is not correct as V is the anther
D is not correct as R is the petal
1(a)(iii) The only correct answer is
C as T is the ovule
A is not correct as P is the stigma
B is not correct as S is the ovary
D is not correct as V is the anther
1 (b) An answer that makes reference to three of the following:
- large petals /eq (1)
- coloured petals / bright petals / scented petals (1)
- stigma / style within flower / stigma sticky / eq (1)
- stamen / anther within flower / eq(1)
- nectary (1)
- ollen large / sticky /eq (1)
1 (c) An explanation that refers to two of the following:
- eaten by birds / animals / people / insects / eq (1)
- disperse / taken / moved / carried to new area / elsewhere / eq (1)
- egested / deposited / waste / defecate / thrown away / discarded / in faeces / eq (1)
Question 2
The diagram shows a transverse section through a human heart.
(a) (i) Draw an X on the diagram to show the position of the septum.
(ii) State two differences between the composition of the blood in the coronary artery and the composition of the blood in the coronary vein.
(iii) Explain the differences between the left ventricle wall and the right ventricle wall.
(b) The development of coronary heart disease is linked to a number of factors.
Explain how these factors can increase the risk of developing coronary heart disease.
2(a)(i)
▶️Answer/Explanation
2(a)(ii) An answer that makes reference to the following
- coronary artery contains (more) oxygen / oxygenated (1)
- coronary artery contains less carbon dioxide / no carbon dioxide (1)
2(a)(iii) An explanation that makes reference to three of the following
- (left wall) much thicker / eq (1)
- more muscle / muscular (tissue) / eq (1)
- (generates) more pressure / more force /eq (1)
- pumps blood (all) around body / eq (1)
2(b) An explanation that makes reference to four of the following
1. genetics / inheritance / some people inherit increased risk from parents eq (1)
2. high blood pressure (puts more strain on heart ) / eq (1)
3. high fat diet / lipid / cholesterol / (blocks coronary artery walls) / eq (1)
4. smoking (raises blood pressure and increase chances of clots) / eq (1)
5. stress (raises blood pressure) / eq (1)
6. lack of exercise , (exercise reduces blood pressure and strengthens heart) / eq (1)
7. obesity / being overweight / diabetes (increase strain on heart) / eq (1)
Question 3
The diagram shows the nutritional content of two non‐dairy milk products, oat milk and almond milk.
(a) (i) A person is told by their doctor that they need to lose weight. Use the information from the milk contents and your own knowledge to discuss which milk would be the most suitable for this person.
(ii) Suggest why a person might drink a non‐dairy milk such as oat or almond milk rather than cow’s milk.
(b) Describe how a student could test a milk sample for glucose.
(c) Human breast milk contains special proteins that give immunity to the baby.
Explain how these proteins can help protect the baby from disease.
▶️Answer/Explanation
3(a)(i) An answer that makes reference to five of the following
1. oat milk provides more energy kJ / calories / (per 225 g) / eq (1)
2. more energy less weight loss / idea of carbohydrate / fats not used so stored / so more weight gain/ eq (1)
3. oat provides more (saturated) fat / eq (1)
4. oat provides more carbohydrate / eq (1)
5. oat provides similar sugar / same sugar/eq (1)
6. oat provides more protein ( required for growth ) / eq (1)
7. oat milk provides more fibre (1)
8. for peristalsis /prevent constipation / eq
9. but balance diet required / depends upon other foods consumed / eq (1)
10.weight loss depends upon activity age / eq (1)
3(a)(ii) An answer that makes reference to the following
- allergy / allergic / lacks enzyme / lactase / lactose intolerant / wants reduced (saturated) fat diet / cow’s milk contains more fat / are vegan / wants to avoid constipation as cow’s milk has no fibre / eq (1)
3(b) A description that makes reference to two of the following
- Benedict’s added / eq (1)
- heated / eq (1)
- red / green / yellow / orange / eq (1)
3(c) An explanation that makes reference to three of the following
- antibodies (1)
- (specific to / against / for) antigen / virus / bacterium /pathogen / eq (1)
- stick / clump / burst / label bacteria / virus/ pathogen/eq (1)
- destroy / kill bacteria / virus / pathogen / eq (1)
Question 4
The peppered moth is found in many countries.
Two different forms of the peppered moth are a light‐coloured moth and a dark‐coloured moth.
The dark‐coloured moth was first observed in cities when pollution, from burning coal, stained tree trunks black.
Scientists trapped moths in a city location from 1992 to 1998.
The table shows the scientists’ results.
(a) Calculate the difference between the percentage of moths that are dark‐coloured in 1992 and the percentage of moths that are dark‐coloured in 1998.
(b) (i) Plot a line graph to show the number of light‐coloured moths and the number of dark‐coloured moths from 1992 to 1998.
Use a ruler to join the points with straight lines.
(ii) In the 1990s, many cities introduced laws that prevented the burning of coal.
Comment on the changes in the number of light‐coloured moths and the number of dark‐coloured moths between 1992 and 1998.
▶️Answer/Explanation
4(a) calculation
% dark-coloured moths in 1992
27÷ 36 × 100
= 75%
% dark-coloured moths in 1998
9÷ 22 × 100
= 41%
75 – 41 = 34(%) (3) allow 34.1 or 34.09 etc
4 (b)(i)
- Scale half grid and linear (1)
- Lines straight and through all points (1)
- Axis correct way round and labelled with number of moths (and year) (1)
- Points correctly plotted within half a small square (1)
- Key light-coloured and dark-coloured moths or lines labelled (1)
4(b)(ii) An answer that makes reference to five of the following
1. numbers of light increases / (decrease then) increase (1)
2. numbers of dark decrease (then increase) / eq (1)
3. overall total numbers of moths decrease (then increase)/ eq (1)
4. due to disease predation lack of food /eq (1)
5. at start / up until 1994 more dark than light moths / eq (1)
6. at end (from 1994) more light than dark moths ( apart from 1996) / eq (1)
7. as less coal (used) / burning / pollution in city decreased / eq (1)
8. dark less camouflaged / cannot hide / light more/ better camouflaged / better adapted in unpolluted areas OR dark better adapted in polluted areas / eq (1)
9. easily seen by birds / predators / eq (1)
10. (better adapted) pass on allele / gene to offspring / eq(1)
Question 5
The chromosomes in a human cell can be photographed and then arranged in pairs to show the karyotype.
White blood cells are often used to show the chromosomes in the karyotype.
The chromosomes in white blood cells are larger and easier to see when the white blood cells divide.
Diagram 1 shows a karyotype.
(a) (i) Explain why a red blood cell cannot be used to show a karyotype.
(ii) State the type of cell division that occurs in white blood cells.
(iii) The karyotype in diagram 1 is from a male.
State how this can be deduced from the diagram.
(b) Diagram 2 shows a karyotype from a white blood cell of another person.
The karyotype is from a female, and the person has a condition called Turner syndrome.
This condition affects the development of the ovaries so they may not produce normal quantities of sex hormones.
(i) Comment on the differences between the karyotypes shown in diagram 1 and diagram 2 and the effects Turner syndrome will have on the person.
Use information from the question and your own knowledge in your answer.
(ii) Suggest how the difference in the chromosomes of people with Turner syndrome may have been produced.
▶️Answer/Explanation
5(a)(i) An explanation that makes reference to the following
- no nucleus (1)
- (so) no chromosomes (1)
5(a)(ii)
- mitosis / mitotic (1)
5(a)(iii) An answer that includes
- contains a Y chromosome / has X and Y chromosomes / only one X chromosome / 23 rd pair are different / 23 one big one small / eq (1)
5(b)(i) An answer that makes reference to four of the following
1. karyotype 2 45 chromosomes /karyotype 1 46 chromosomes / only one in 23 rd pair / one less chromosome /eq (1)
2. karyotype 2 only 1 X / one sex chromosome / lacks an X or lacks a Y / eq (1)
3. so female karyotype as it lacks Y / eq (1)
4. does not undergo normal puberty/ delayed puberty eq (1)
5. does not develop secondary sexual characteristics / eq (1)
6. cannot release oestrogen / less oestrogen / eq (1)
7. cannot produce gametes / eggs / is infertile / cannot reproduce / eq (1)
8. slower repair of inner uterus lining/lining not being maintained (1)
9. may produce gametes that contain only 22 chromosomes / lack a sex chromosome / eq (1)
5(b)(ii)
- mutation / failure of chromosomes to separate / failure in meiosis / one of the sex chromosomes did not replicate (just prior to cell division) / eq (1)
Question 6
A student uses this method to investigate osmosis in potato tissue.
• cut three 5.0cm long cylinders from a raw potato
• dry the cut surfaces using filter paper
• measure the mass of each cylinder using a balance
• place one cylinder in a test tube containing 10cm3 of concentrated sucrose solution, one cylinder in a test tube containing 10cm3 of distilled water and one cylinder in an empty test tube
• put a bung in each test tube and leave them for one hour
• remove the cylinders and dry them with filter paper
• measure the mass of each cylinder again
• measure their lengths using a ruler
(a) (i) Describe what is meant by the term osmosis.
(ii) State the independent variable in the student’s investigation.
(b) Osmosis is affected by the surface area and volume of the cylinders, so the student keeps the original surface area and volume of each cylinder the same.
At the start of the experiment each cylinder had a radius of 0.25cm and a length of 5.0cm.
(i) Calculate the surface area of each cylinder using this formula.
surface area = 2πrl +2πr2
[l = length of cylinder, r = radius of cylinder and π = 3.14]
surface area = …………………………………………………….. cm2
(ii) Explain how surface area would affect the rate of osmosis.
(iii) State another variable the student should control in the investigation.
(c) The table shows the student’s results for the mass of the cylinders.
(i) Explain the changes in the mass of the potato cylinder in each test tube.
(ii) The student also measured the change in length of each potato cylinder.
Assuming the length has the same percentage change as the mass, calculate the final length of the cylinder in the concentrated sucrose solution.
length = …………………………………………………….. cm
▶️Answer/Explanation
6(a)(i) A description that makes reference to the following
- diffusion / movement of solvent / water through partially permeable membrane / eq (1)
- from dilute to concentrated solution / high to low water potential / eq (1)
6(a)(ii)
- tube contents / the liquid / the solution / the concentration / what is in the tube / eq (1)
6(b)(i) calculation
= (2 × 3.14 x 0.25 x 5) + (2 × 3.14 × (0.25)2)
= 7.85 + 0.3925
= 8.2425
= 8.2 (cm 2) to 8.25 (2)
6(b)(ii) An explanation that makes reference to the following
- increases rate of osmosis / eq (1)
- as more contact (between potato and water / solution ) / more space / eq (1)
6(b)(iii)
- temperature / type of potato / eq (1)
6(c)(i) An explanation that makes reference to three of the following
- distilled water (increases in mass) water enters potato from distilled water (1)
- air (little change in mass) no movement of water / no osmosis / water evaporates / eq (1)
- sucrose solution (decrease in mass) water leaves potato into sucrose solution / eq (1)
- Correct ref to water potential gradient or from dilute solution to concentrated solution / down water potential gradient / from higher concentration of water to lower concentration of water / eq (1)
6(c)(ii) calculation
percentage change in mass in sucrose solution
= (1.8- 2.1)÷ 2.1 = -0.3
-0.3 ÷2.1
= -0.143
× 100
= – 14.3 %
14.3 % of 5.0 cm =
0.143 ×5 = -0.71cm
5-0.71 = 4.3(4.29) allow 4.28 to 4.3 cm (3)
Question 7
This food web is from an ecosystem in Africa.
(a) (i) Which organism is a primary consumer?
A acacia
B lion
C star grass
D zebra
(ii) Which of these has the least efficient energy transfer?
A giraffe to cheetah
B star grass to baboon
C wildebeest to wild dog
D zebra to lion
(iii) Which organism will be least affected by a reduction in the population of star grass?
A baboon
B gazelle
C wildebeest
D zebra
(b) (i) Explain why only a small proportion of the energy contained within one trophic level is transferred to the next trophic level.
(ii) Describe how a scientist could compare the population size of star grass in two areas of the ecosystem.
(c) Wild dogs hunt a variety of prey species. They usually eat the weak and sick animals.
Explain how this behaviour may benefit the species the dogs hunt.
▶️Answer/Explanation
7(a)(i) The only correct answer is D zebra
A is not correct as acacia is a producer
B is not correct as lion is a secondary consumer
C is not correct as star grass is a producer
7(a)(ii) The only correct answer is
B star grass to baboon
A is not correct as giraffe to cheetah is not least efficient
C is not correct as wildebeest to wild dog is not least efficient
D is not correct as zebra to lion is not least efficient
7(a)(iii) The only correct answer is
B gazelle
A is not correct as baboon is affected more
C is not correct as wildebeest is affected more
D is not correct as zebra is affected more
7(b)(i) An explanation that makes reference to four of the following
- not all organisms consumed /eq (1)
- some die / decompose / eq (1)
- some parts not eaten / bones /eq (1)
- energy lost as heat / respiration / used in movement / muscle contraction / eq (1)
- some food not digested /absorbed / egested / faeces /eq(1)
- energy lost as excretion / urea /eq (1)
7(b)(ii) A description that makes reference to four of the following
- quadrat / eq (1)
- (placed) at random / use random number generator / eq (1)
- count (number in each quadrat) / eq (1)
- repeat / take average / eq (1)
- multiply up / scale up to calculate numbers in area / eq (1)
7(c) An explanation that makes reference to the following
- weakest prey killed / faster / stronger survive / eq (1)
- (strongest mate) / reproduce / weakest do not reproduce / eq (1)
- pass on alleles / genes / genetic material / DNA / eq (1)
- (sick animals removed) prevents infection / bacteria / virus / pathogen spreading / eq (1)
- weak animals slow down herd / eq (1)
Question 8
Yeast can be used in food production.
(a) (i) Which group of organisms does yeast belong to?
A bacteria
B fungi
C plants
D protoctists
(ii) Which substance is the cell wall of a yeast cell made of?
A cellulose
B chitin
C sucrose
D starch
(b) A teacher sets up an experiment to investigate the effect of temperature on the rate of respiration in yeast.
The diagram shows part of the apparatus the teacher uses.
(i) Explain what additional apparatus the teacher will need to investigate the effect of temperature on the rate of respiration in this experiment.
(ii) State the purpose of the liquid paraffin on the surface of the glucose solution.
(iii) Give the name of a suitable chemical that could be used as indicator X to show that the yeast is respiring.
(iv) Diazine green changes colour from blue to pink as the oxygen levels in the yeast and glucose solution reduce.
Explain how this colour change gives information about the respiration in the yeast.
(c) Explain why the rate of respiration in the yeast will change as the temperature is increased.
▶️Answer/Explanation
8(a)(i) The only correct answer is
B fungi
A is not correct as yeast is not a bacterium
C is not correct as yeast is not a plant
D is not correct as yeast is not a protoctist
8(a)(ii) The only correct answer is
B chitin
A is not correct as wall is not made of cellulose
C is not correct as wall is not made of sucrose
D is not correct as wall is not made of starch
8(b)(i) An explanation that makes reference to the following
- water bath / Bunsen / thermostat to vary temperature to heat up water / eq (1)
- thermometer to measure temperature / eq (1)
- clock watch / timer to measure time period / how long / rate per minute / eq (1)
8(b)(ii)
- prevent entry of oxygen / makes conditions anaerobic / eq (1)
8(b)(iii)
- limewater / calcium hydroxide solution / hydrogen carbonate indicator / sodium hydrogencarbonate / bicarbonate indicator / sodium bicarbonate (1)
8(b)(iv) An explanation that makes reference to two the following
- originally blue as oxygen present so yeast is respiring (aerobically) / eq (1)
- (changes to pink )(all) oxygen used up / taken in / consumed in (aerobic) respiration / eq (1)
- (when pink / when no oxygen present) now respiring anaerobically /eq (1)
8(c) An explanation that makes reference to four of the following
- enzyme / substrate / particles / molecules move faster / increased (kinetic) energy / eq (1)
- collide more frequently / form more enzyme substrate complexes / eq (1)
- (until) optimum temperature / eq (1)
- then active site changes shape / eq (1)
- substrate no longer fits / binds with enzyme / enzyme denatures / eq (1)
Question 9
Plants need light for photosynthesis.
(a) Give the balanced chemical symbol equation for photosynthesis.
……………………………….. + ………………………………..→ ……………………………….. + …………………………….
(b) The graph shows the effect of light intensity on the rate of photosynthesis in a water plant.
The rate of photosynthesis is measured by counting the number of bubbles of gas released per minute.
The light intensity is decreased by moving a lamp further away from the water plant.
The light intensity is calculated as
= 1÷ (distance in cm of lamp from plant)2
(i) Using information from the graph, calculate the distance of the lamp from the plant when the rate of photosynthesis is 78 bubbles per minute.
(ii) Describe the relationship between the number of bubbles per minute and light intensity.
(iii) Explain the rate of photosynthesis between a light intensity of 0.4 arbitrary units and a light intensity of 0.8 arbitrary units.
▶️Answer/Explanation
9(a)
6CO2 + 6H2O → C6H12O6 + 6O2
9(b)(i) Calculation
78 bubbles per minute gives 1÷d2 value from x axis of 0.16
therefore 1÷d2 = 0.16
d2= 6.25
distance d = 2.5 (cm) (2)
9(b)(ii) A description that makes reference to the following
- more bubbles released / rate of photosynthesis increases / eq (1)
- very steeply at low light intensities / at first / eq (1)
- number of bubbles levels off / becomes constant / stays same / reaches maximum / rate of increase slows down / eq (1)
9(b)(iii) An explanation that makes reference to two of the following
- rate doesn’t change / no change / increasing / changing light / light intensity / has no effect / / eq (1)
- as light no longer / not limiting factor / other factor limiting / eq (1)
- need more carbon dioxide / need higher temperature to increase photosynthesis rate / eq (1)
Question 10
(a) The table gives some information about enzymes in the human digestive system.
Complete the table by giving the missing information.
(b) Some scientists have investigated the effect of vinegar (a weak acid) on the digestion of starch.
Design an investigation to discover the effect of vinegar on the digestion of starch.
Include experimental details in your answer and write in full sentences.
▶️Answer/Explanation
10(a)
10 (b)
C use different concentrations of vinegar / vinegar and no vinegar / range of pH acids / eq (1)
O of same mass of starch / flour / bread /potato / rice / eq (1)
R repeat (for each concentration (of vinegar) / eq(1)
M1 use iodine to test for (digestion of) starch (1)
M2 measure time it takes for all starch to be digested / iodine test to be negative / orange / yellow / or description of negative positive result / eq (1)
S1 same temperature / use water bath / eq (1)
S2 same time to react / same volume of amylase / same concentration of amylase / same mass of amylase / same volume of vinegar / same volume of iodine / same volume Benedic’ts /eq (1)