Food chains and food webs — Paper 3 · IGCSE Science - Combined 0653

4 (a) Define the terms herbivore, … … carnivore. … … [2] (b) Fig. 4.1 shows an aquatic food web. Phytoplankton are microscopic plants that float on the surface of the water. Zooplankton are very small animals. seagull fish crab small invertebrates mussel limpet zooplankton seaweed phytoplankton Fig. 4.1 (i) State two environmental conditions that can affect the rate of photosynthesis of the plants in the water. 1. … 2. … [2] (ii) Using Fig. 4.1 draw one food chain which includes the crab. [2] (iii) The population of crabs decreases. Suggest how this can cause the number of mussels to increase, … … to decrease. … … … [3]

9 marks

Mark scheme: 4(a) an animal that gets its energy / eats (only) plants ; an animal that gets its energy / eats (only) animals ; 2 4(b)(i) (amount of) light / light intensity ; (amount of) carbon dioxide / concentration of carbon dioxide ; 2 4(b)(ii) food chains, any one from seaweedÆlimpetÆcrabÆseagull / phytoplanktonÆmusselÆ crabÆseagull / phytoplanktonÆzooplanktonÆmussel ÆcrabÆseagull ; arrows in correct direction ; 2 4(b)(iii) (increase) crabs no longer feeding on the mussels ; (decrease) seagulls have fewer crabs to feed on ; so they eat more mussels instead ; 3

This question in 0653/31 May/June 2017

7 Fig. 7.1 shows some of the organisms in a lake. Algae are tiny water plants that float on the surface of the lake. light oxygen air algae and water small animals lake water plants fish Fig. 7.1 (a) (i) Explain why the fish in the water need oxygen. … … [1] (ii) The concentration of oxygen is higher in the air than in the water. Name the process which causes oxygen molecules to go from the air into the water. … [1] (iii) Describe another source of oxygen for the fish in the water. … … [1] (b) The feeding relationships of the organisms in Fig. 7.1 are as follows. • the small animals feed on algae • the fish feed on the algae, water plants and small animals. (i) Use the information provided to complete the food web which has been started below. small animals fish algae water plants [2] (ii) From the organisms in Fig. 7.1 name a herbivore, … a producer. … [2]

7 marks

Mark scheme: 7(a)(i) for respiration ; 1 7(a)(ii) diffusion ; 1 7(a)(iii) from the (water) plants ; 1 7(b)(i) food web completed as shown ; small animals fish algae water plants arrows in the correct direction ; 2 7(b)(ii) small animals ; water plants / algae ; 2

This question in 0653/32 May/June 2017

7 Fig. 7.1 shows some of the organisms in a lake. Algae are tiny water plants that float on the surface of the lake. light oxygen air algae and water small animals lake water plants fish Fig. 7.1 (a) (i) Explain why the fish in the water need oxygen. … … [1] (ii) The concentration of oxygen is higher in the air than in the water. Name the process which causes oxygen molecules to go from the air into the water. … [1] (iii) Describe another source of oxygen for the fish in the water. … … [1] (b) The feeding relationships of the organisms in Fig. 7.1 are as follows. • the small animals feed on algae • the fish feed on the algae, water plants and small animals. (i) Use the information provided to complete the food web which has been started below. small animals fish algae water plants [2] (ii) From the organisms in Fig. 7.1 name a herbivore, … a producer. … [2]

7 marks

Mark scheme: 7(a)(i) for respiration ; 1 7(a)(ii) diffusion ; 1 7(a)(iii) from the (water) plants ; 1 7(b)(i) food web completed as shown ; small animals fish algae water plants arrows in the correct direction ; 2 7(b)(ii) small animals ; water plants / algae ; 2

This question in 0653/33 May/June 2017

4 Fig. 4.1 shows diagrams of primrose flowers. The flowers have two slightly different forms, C and D. stigma anther anther stigma C D Fig. 4.1 (a) Describe two pieces of evidence from Fig. 4.1 that suggest these primroses are insect-pollinated. 1. … … 2. … … [2] (b) Compare the diagrams in Fig. 4.1 and predict which flower, C or D, is more likely to be pollinated by its own pollen. Explain your answer. flower … explanation … … … … [2] (c) Cross-pollination is the transfer of pollen from one flower to another flower on a different plant. This leads to the production of seeds. State and explain why the genetic material in the seeds is different from the genetic material in the parent plants. … … … … [2] (d) The following feeding relationships occur in the field where the primroses grow. • thrushes feed on snails • snails feed on primroses • buzzards feed on thrushes (i) Draw a food chain to show the flow of energy through these organisms. [2] (ii) State all of the organisms in the food chain which are consumers. Explain your answer. consumers … explanation … … … [2]

10 marks

Mark scheme: 4(a) Any two from (large) petals ; anther(s) / are inside the flower ; stigma / is inside the flower ; max 2 4(b) (flower) D AND any two from anther is higher than stigma ; anther produces pollen ; pollen is more likely to fall on it ; max 2 4(c) sexual reproduction ; from different parents / different genetic material ; (seeds contain) some (genetic material) from each parent ; max 2 Question Answer Marks 4(d)(i) primroses → snails → thrushes → buzzards correct order ; correct arrows ; 2 4(d)(ii) snails, thrushes, buzzards ; (get their energy by) feeding on other organisms ; 2

This question in 0653/31 Oct/Nov 2017

7 (a) During transpiration water is lost from the leaves of a plant. An experiment is carried out to compare the transpiration rates of the upper and lower surfaces of leaves of three similar plants, N, U and B, using the apparatus shown in Fig. 7.1. The leaves of two plants are treated with petroleum jelly, a waterproof substance which prevents evaporation from the surface of the leaf. plastic bag to prevent water from evaporating from the soil balance plant N plant U plant B no petroleum jelly petroleum jelly on the petroleum jelly on both upper surface of leaves surfaces of the leaves Fig. 7.1 The masses of plants N, U and B are measured. After six hours the mass of each plant is measured again and the mass of water lost from each plant is calculated. The results are shown in Fig. 7.2. 10.0 9.0 8.0 7.0 6.0 mass of water lost / g 5.0 4.0 3.0 2.0 1.0 0 plant N plant U plant B Fig. 7.2 (i) Use the results in Fig. 7.2 to state which surface of the leaf, upper or lower, loses more water. Explain your answer. surface … explanation … … … … [2] (ii) Explain your conclusion to (i) in terms of leaf structure. … … … [2] (b) Water is taken in at the roots and travels upwards to the leaves through the stem. Fig. 7.3 shows the tissues found in a cross-section of a plant stem. Fig. 7.3 Label the tissue that transports water with the correct name. [2] (c) Water is one of the raw materials needed for photosynthesis. Complete the word equation for photosynthesis. lightwater + + chlorophyll [1] (d) Green plants are producers which rely on the Sun to provide light energy for photosynthesis. Explain why carnivores cannot survive without producers. … … … [2]

9 marks

Mark scheme: 7(a)(i) lower surface when upper leaf is greased water loss is not reduced by much ; when lower surface is covered there is a great reduction in water loss ; 2 7(a)(ii) most transpiration occurs through the stomata ; which are (mostly) found on lower surface of leaf ; 2 7(b) xylem ; position of tissue correctly labelled ; 2 7(c) carbon dioxide, sugar / glucose, oxygen ; 1 Question Answer Marks 7(d) Any two from carnivores cannot produce their own food / cannot photosynthesise ; carnivores get energy by eating herbivores ; herbivores feed on producers ; max 2

This question in 0653/32 Oct/Nov 2017

7 (a) Fig. 7.1 shows a food web in a garden. owl cats small birds mice snails caterpillars green plants Fig. 7.1 (i) Use Fig. 7.1 to name the producer, … the herbivores. … [2] (ii) Using information in Fig. 7.1 draw a complete food chain consisting of only three organisms. [2] (b) The caterpillars in the food web in Fig. 7.1 are only present in the garden for three months of the year. Suggest and explain the effect of the disappearance of caterpillars on the number of snails. … … [1]

5 marks

Mark scheme: 7(a)(i) green plants ; mice, snails, caterpillars ; 2 7(a)(ii) green plants mice owl correct organisms in the correct order ; arrows correct, in correct direction ; 2 Question Answer Marks 7(b) decrease – no mark the small birds will eat more snails ; or increase – no mark more food for snails when caterpillars disappear ; 1

This question in 0653/31 May/June 2018

4 Fig. 4.1 shows part of an aquatic food web. sealion octopus crab seagull shellfish starfish seaweed Fig. 4.1 (a) From Fig. 4.1 state the name of a producer, … a herbivore, … a consumer. … [3] (b) The food web in Fig. 4.1 is made from interconnected food chains. Write two complete food chains which contain the crab. 1. … 2. … [3] (c) The population of crabs reduces suddenly. Suggest two reasons why this causes the octopus population to decrease. 1. … … 2. … … [2]

8 marks

Mark scheme: 4(a) seaweed ; shellfish ; shellfish / crab / starfish / seagull / sealion / octopus 3 Question Answer Marks 4(b) any two of seaweed → shellfish → crab → seagull ; seaweed → shellfish → crab → sea lion ; seaweed → shellfish → crab → octopus → sea lion ; and food chains set out correctly with arrows going in the right direction ; 3 4(c) (Fewer crabs) so sea lion eats more octopus ; Fewer crabs for octopus / less food for octopus / octopus loses part of its food supply ; 2

This question in 0653/31 Oct/Nov 2018

1 (a) Fig. 1.1 shows diagrams of two plant cells as seen using a light microscope. chloroplast starch grains E nucleus F potato cell mesophyll cell from leaf Fig. 1.1 (i) Name parts E and F in the potato cell. E … F … [2] (ii) Use Fig. 1.1 to describe one difference between the starch grains and the chloroplasts. … … [1] (iii) Describe a chemical test and the positive result for starch. test … positive result … [2] (b) (i) Starch is a carbohydrate. Name the smaller molecules that join together to make a starch molecule. … [1] (ii) Explain why starch must be broken down by chemical digestion. … … … [2] (c) Fig. 1.2 shows a food chain in a garden. lettuce snail hedgehog fox Fig. 1.2 Table 1.1 shows some words to describe some of the organisms in the food chain. Place a tick (✓) in all boxes that correctly describe each organism. Table. 1.1 organism carnivore consumer herbivore producer lettuce snail hedgehog [3] [Total: 11]

11 marks

Mark scheme: 1(a)(i) (E) vacuole ; (F) cytoplasm ; 2 1(a)(ii) starch grains irregular shapes / sizes and chlorophyll all the same shapes / sizes ; 1 1(a)(iii) add iodine solution ; goes blue-black ; 2 1(b)(i) glucose ; 1 1(b)(ii) produces small molecules ; that can be absorbed ; 2 1(c) one mark for each correct line organism carnivore consumer herbivore producer lettuce 3 snail 3 3 hedgehog 3 3 ; ; ; 3

This question in 0653/32 Feb/March 2019

4 (a) Fig. 4.1 shows some leaves of the plant Mimosa pudica. before touching after touching Fig. 4.1 When a person touches a leaf, the leaf closes within three seconds. (i) State which two characteristics of living things are being shown by the leaf after it is touched. 1. … 2. … [2] (ii) Predict how the rate of photosynthesis is affected by leaves showing the response in Fig. 4.1. Explain your answer. prediction … explanation … … [1] (b) (i) Fig. 4.2 shows some organisms found in a field. mouse (primary consumer) badger (tertiary consumer) snake (secondary consumer) wheat (producer) Fig. 4.2 Draw a food chain of the four organisms. You do not need to include the pictures. [2] (ii) Name a carnivore and a herbivore from the organisms shown in (b)(i). carnivore … herbivore … [2] (c) State the principal source of energy for the food chain you wrote in (b)(i). … [1] [Total: 8]

8 marks

Mark scheme: 4(a)(i) sensitivity ; movement ; 2 4(a)(ii) rate stops / reduces and less leaf area / less light (energy) absorbed ; 1 Question Answer Marks 4(b)(i) wheat mouse snake badger correct order of organisms ; arrows going in correct direction ; 2 4(b)(ii) snake / badger ; mouse ; 2 4(c) Sun ; 1

This question in 0653/33 May/June 2019

7 (a) Fig. 7.1 shows information about the organisms in a food chain. grass – producer owl – tertiary consumer cricket – primary consumer frog – secondary consumer Fig. 7.1 (i) Write down the food chain using the information in Fig. 7.1. … [2] (ii) Define the term producer. … … … [2] (b) Explain why chemical digestion is needed in the alimentary canals of consumers. … … … … [2] (c) (i) State why deforestation can disrupt the food chains in a forest. … … [1] (ii) State one other harmful effect of deforestation. … [1] [Total: 8]

8 marks

Mark scheme: 7(a)(i) grass cricket frog owl organisms in correct order ; arrows in correct direction ; 2 7(a)(ii) (an organism that) makes its own (organic) nutrients/food ; using energy from (sun)light / photosynthesis ; 2 7(b) any two from: the breakdown of large, insoluble food molecules ; into small water-soluble molecules ; so (small molecules) can be absorbed ; 2 7(c)(i) loss of shelter / loss of habitat / loss of food / reduction in population of part of food chain ; 1 7(c)(ii) loss of soil / flooding / increase of carbon dioxide in the atmosphere ; 1

This question in 0653/31 Oct/Nov 2019

1 (a) Fig. 1.1 shows two cells. S R cell P cell Q Fig. 1.1 (not to scale) (i) Identify structures R and S, as shown on Fig. 1.1. R … S … [2] (ii) Cell Q is a plant cell. State two pieces of evidence from Fig. 1.1 that support this statement. 1. … 2. … [2] (b) Complete the word equation for photosynthesis. light + + chlorophyll [2] (c) One of the food chains in a garden is shown in Fig. 1.2. lettuce snail thrush owl Fig. 1.2 (i) Name one organism in the food chain shown in Fig. 1.2 which is a herbivore. … [1] (ii) Name one organism in the food chain shown in Fig. 1.2 which is a secondary consumer. … [1] (iii) A gardener removes the lettuces. Suggest what happens to the number of snails. Explain your answer. the number of snails will … explanation … … [1] [Total: 9]

9 marks

Mark scheme: 1(a)(i) R cell membrane ; S cytoplasm ; 2 1(a)(ii) any two from: (it has a) cell wall ; (it has a large) vacuole ; (it has) chloroplasts ; 2 1(b) (LHS) carbon dioxide + water ; (RHS) glucose + oxygen ; 2 1(c)(i) snail ; 1 1(c)(ii) thrush ; 1 1(c)(iii) decrease and (they have) less food / no food ; 1

This question in 0653/32 Oct/Nov 2019

1 (a) Fig. 1.1 shows two cells. S R cell P cell Q Fig. 1.1 (not to scale) (i) Identify structures R and S, as shown on Fig. 1.1. R … S … [2] (ii) Cell Q is a plant cell. State two pieces of evidence from Fig. 1.1 that support this statement. 1. … 2. … [2] (b) Complete the word equation for photosynthesis. light + + chlorophyll [2] (c) One of the food chains in a garden is shown in Fig. 1.2. lettuce snail thrush owl Fig. 1.2 (i) Name one organism in the food chain shown in Fig. 1.2 which is a herbivore. … [1] (ii) Name one organism in the food chain shown in Fig. 1.2 which is a secondary consumer. … [1] (iii) A gardener removes the lettuces. Suggest what happens to the number of snails. Explain your answer. the number of snails will … explanation … … [1] [Total: 9]

9 marks

Mark scheme: 1(a)(i) R cell membrane ; S cytoplasm ; 2 1(a)(ii) any two from: (it has a) cell wall ; (it has a large) vacuole ; (it has) chloroplasts ; 2 1(b) (LHS) carbon dioxide + water ; (RHS) glucose + oxygen ; 2 1(c)(i) snail ; 1 1(c)(ii) thrush ; 1 1(c)(iii) decrease and (they have) less food / no food ; 1

This question in 0653/33 Oct/Nov 2019

7 (a) Fig. 7.1 shows part of the alimentary canal and associated organs. W pancreas Fig. 7.1 (i) Name the part W shown in Fig. 7.1. … [1] (ii) Some people need to have their pancreas removed due to illness. Describe how removing the pancreas may affect the person’s digestion. … … … [2] (iii) The pancreas also produces hormones. Place ticks (✓) in two boxes to show the correct ideas about hormones. alter the activity of organs HIV is one example of a hormone they are chemical substances produced by target organs transported in red blood cells [2] (b) Fig. 7.2 shows a food web. jaguar deer fox squirrel pine cones on a pine tree berries on a bush Fig. 7.2 (i) Identify one animal shown in Fig. 7.2 that feeds on the pine tree. … [1] (ii) The fox is both a primary consumer and a secondary consumer. Use the names of organisms shown in Fig. 7.2 to complete these sentences to explain why. The fox is a primary consumer when … … The fox is a secondary consumer when … … [2] (iii) Berries contain seeds. Seeds germinate and grow into new plants. State two environmental conditions needed for germination of seeds. 1 … 2 … [2] [Total: 10]

10 marks

Mark scheme: 7(a)(i) gall bladder ; 1 7(a)(ii) the pancreas secretes, pancreatic juice / enzymes (for digestion) ; (therefore) less digestion can take place ; 2 Question Answer Marks 7(a)(iii) alter the activity of organs  breakdown large insoluble molecules chemical substances  produced by target organs transported in red blood cells ;; all correct = 2 mark two ticks one correct = 1 mark three ticks two correct = 1 mark more than 3 ticks = 0 marks ;; 2 7(b)(i) squirrel / deer ; 1 7(b)(ii) (The fox is a primary consumer when) eats berries ; (The fox is a secondary consumer when) eats squirrel ; 2 7(b)(iii) any two from: water ; oxygen ; suitable temperature ; max 2

This question in 0653/32 Feb/March 2020

7 (a) Fig. 7.1 shows a food web. coyote hawk roadrunner rattlesnake scorpion rabbit grasshopper grass cactus Fig. 7.1 (i) The food web is not complete. Scorpions are eaten by roadrunners. Use this information to complete the food web in Fig. 7.1 by drawing one arrow. [1] (ii) Identify one tertiary consumer from the food web in Fig. 7.1. … [1] (iii) One year the number of rattlesnakes decreases. This leads to a decrease in the number of grasshoppers. Explain why using the information in Fig. 7.1. … … … … [2] (b) Fig. 7.2 is a diagram of a cactus growing in a desert. Fig. 7.2 The cactus is a flowering plant. A bird feeds on the nectar produced by the flowers. As it feeds, pollen sticks to the bird and can be moved from one flower to another. Complete the sentences using words from the list. Each word may be used once, more than once or not at all. agent anther catalyst ovule petals sepals stigma The cactus flower is pollinated when pollen is transferred to the … . The bird is the … of pollination. The flower has nectar and coloured … to attract the bird. [3] [Total: 7]

7 marks

Mark scheme: 7(a)(i) arrow drawn from scorpion to roadrunner ; 1 7(a)(ii) any one from: roadrunner ; hawk ; coyote ; max 1 7(a)(iii) roadrunners will have less rattlesnakes to eat ; roadrunners will need to eat more grasshoppers ; or less rabbits eaten ; rabbits eat more grass / less grass for grasshoppers ; 2 7(b) stigma ; agent ; petals ; 3

This question in 0653/31 May/June 2020

1 (a) Fig. 1.1 shows a food web for a pond habitat. kingfisher fish frog tadpole water beetle snail algae Fig. 1.1 (i) Identify the producer shown in Fig. 1.1. … [1] (ii) State the process used by producers to make glucose using energy from sunlight. … [1] (iii) Identify one carnivore shown in Fig. 1.1. … [1] (iv) Use the information in Fig. 1.1 to construct a food chain including the frog. … [1] (b) Decomposers are also found in pond habitats. Define a decomposer. … … [1] (c) Decomposers are an important part of the carbon cycle. Fig. 1.2 shows a diagram of the carbon cycle. combustion fossil fuel X Y carbon dioxide in photosynthesis green plants the atmosphere decomposition Z X animals Fig. 1.2 Identify processes X, Y and Z shown in Fig. 1.2. X … Y … Z … [3] [Total: 8]

8 marks

Mark scheme: 1(a)(i) algae ; 1 1(a)(ii) photosynthesis ; 1 1(a)(iii) frog / fish / kingfisher ; 1 1(a)(iv) algae → snail / water beetle → frog → kingfisher ; 1 1(b) (an organism that) gets its energy from dead or waste organic matter ; 1 1(c) X respiration ; Y fossilisation ; Z feeding ; 3 Question Answer Marks

This question in 0653/32 Oct/Nov 2020

7 (a) Fig. 7.1 shows a picture of a sloth and some information about sloths. Sloths live in the Amazon rainforest. They feed on the leaves of trees. Sloths are eaten by an animal called a jaguar. Fig. 7.1 (i) Use the information in Fig. 7.1 to construct the food chain for the sloth. … [2] (ii) Complete this sentence about the sloth. The sloth is a … consumer because it eats the producer. [1] (b) Rainforests are being destroyed by deforestation. Fig. 7.2 shows the area of deforestation each year in the Amazon rainforest. 30 000 25 000 20 000 area of deforestation / km2 15 000 10 000 5 000 0 1994 1996 1998 2000 2002 2004 2006 2008 2010 year Fig. 7.2 (i) State the year that had the greatest amount of deforestation. … [1] (ii) Explain why the trend seen in deforestation between 2004 and 2010 benefits sloths. … … … … [2] (c) Plants in the rainforest take up water and mineral ions from the soil. Fig. 7.3 is a diagram showing some of the cells in the root of a plant. soil particles root … cell xylem vessel root hair Fig. 7.3 (i) Complete the label on Fig. 7.3 to identify the cells between the root hair and the xylem vessels. [1] (ii) Draw one arrow to show the pathway taken by water from the soil into the root. [1] (iii) Describe how water moves in and out of cells. … … … [2] [Total: 10]

10 marks

Mark scheme: 7(a)(i) leaves → sloth → jaguar correct order ; arrows in right direction ; 7(a)(ii) primary ; 1 7(b)(i) 1995 ; 1 Question Answer Marks 7(b)(ii) any two from: amount of deforestation is decreasing ; less habitat being destroyed ; decrease in (the rate of) loss of leaves / food source ; 2 7(c)(i) cortex ; 1 7(c)(ii) arrow drawn going into the root hair ; 1 7(c)(iii) by, diffusion / osmosis ; through a partially permeable membrane ; 2

This question in 0653/33 Oct/Nov 2020

7 (a) Fig. 7.1 shows part of a food web from a lake. pike perch water beetle stickleback duck freshwater caddis fly snail larva water flea pondweed algae Fig. 7.1 (i) Identify one tertiary consumer shown in the food web in Fig. 7.1. … [1] (ii) Identify one herbivore shown in the food web in Fig. 7.1. … [1] (iii) The food web is not complete. Ducks eat freshwater snails and pondweed. Draw two arrows on Fig. 7.1 to complete the food web to include this information. [1] (b) Pondweed can be used to investigate photosynthesis. Fig. 7.2 shows how the gas made by the process of photosynthesis can be collected. gas test-tube beaker light water funnel pondweed Fig. 7.2 (i) State the name of the gas that collects in the test-tube. … [1] (ii) When the light is switched off the experiment in Fig. 7.2 is in the dark and the amount of gas being produced by the pondweed changes. Suggest the change in the amount of gas being produced by the pondweed when the light is switched off. Give a reason for your answer. change in the amount of gas … reason … … [2] (c) Water is needed for the process of photosynthesis. Name the vessels in the plant that transport water. … [1] (d) Glucose is made by the process of photosynthesis. Plants use another process to release energy from glucose. Name the process that releases energy from glucose. … [1] [Total: 8]

8 marks

Mark scheme: 7(a)(i) perch / pike ; 1 7(a)(ii) freshwater snail / caddis fly larva / water flea ; 1 7(a)(iii) arrow from freshwater snail to duck AND arrow from pondweed to duck ; 1 7(b)(i) oxygen ; 1 7(b)(ii) less / no, gas produced ; (because) light is needed for photosynthesis ; 2 7(c) xylem ; 1 7(d) (aerobic) respiration ; 1

This question in 0653/32 Feb/March 2021

7 (a) Fig. 7.1 shows a food web. barn owls voles shrews mice worms and insects berries and nuts dead leaves grasses Fig. 7.1 (i) State the principal source of energy for a food web. … [1] (ii) The owl is the top carnivore in this food web. Define the term carnivore. … … [1] (iii) Complete the sentence to explain why shrews are classed as secondary consumers in this food web. Shrews are secondary consumers because they eat … , which are … consumers. [2] (b) Grass roots take in mineral ions from the soil to make amino acids. (i) State the name of the mineral ions needed to make amino acids. … [1] (ii) Grasses take in water from the soil through the root hair cells. Describe how water moves into root hair cells. … … … … [2] [Total: 7]

7 marks

Mark scheme: 7(a)(i) Sun ; 1 7(a)(ii) animal that gets its energy by eating only other animals ; 1 7(a)(iii) worm and insects ; primary ; 2 7(b)(i) nitrate (ions) ; 1 7(b)(ii) (water moves) through, partially permeable membranes / cell membranes ; by osmosis ; 2

This question in 0653/33 May/June 2021

7 (a) Fig. 7.1 contains information about some organisms. • giraffes eat trees • lions hunt and eat giraffes • when lions die, vultures feed on parts of their dead bodies • the parts of the lion not eaten then decompose Fig. 7.1 (i) Construct the food chain for the organisms in Fig. 7.1. … [2] (ii) Identify the secondary consumer from Fig. 7.1. … [1] (iii) Giraffes are herbivores. State what is meant by herbivore. … … [2] (iv) Decomposition of the lion’s body returns carbon to the atmosphere as part of the carbon cycle. State the part of the carbon cycle that removes carbon from the atmosphere. … [1] (b) Living organisms are made up of cells. Cells contain different structures. State the functions of the cell membrane and the cell wall. cell membrane … … cell wall … … [2] [Total: 8]

8 marks

Mark scheme: 7(a)(i) tree(s) → giraffe(s) → lion(s) → vulture(s) all organisms correct ; correct arrows ; 7(a)(ii) lion ; 1 7(a)(iii) (an animal that) gets its energy ; by (only) eating plants ; 2 7(a)(iv) photosynthesis ; 1 7(b) (membrane) controls the movement of substances in and out of the cells ; provides support ; 2

This question in 0653/32 Oct/Nov 2021

7 (a) Fig. 7.1 contains information about some organisms. • giraffes eat trees • lions hunt and eat giraffes • when lions die, vultures feed on parts of their dead bodies • the parts of the lion not eaten then decompose Fig. 7.1 (i) Construct the food chain for the organisms in Fig. 7.1. … [2] (ii) Identify the secondary consumer from Fig. 7.1. … [1] (iii) Giraffes are herbivores. State what is meant by herbivore. … … [2] (iv) Decomposition of the lion’s body returns carbon to the atmosphere as part of the carbon cycle. State the part of the carbon cycle that removes carbon from the atmosphere. … [1] (b) Living organisms are made up of cells. Cells contain different structures. State the functions of the cell membrane and the cell wall. cell membrane … … cell wall … … [2] [Total: 8]

8 marks

Mark scheme: 7(a)(i) tree(s) → giraffe(s) → lion(s) → vulture(s) all organisms correct ; correct arrows ; 7(a)(ii) lion ; 1 7(a)(iii) (an animal that) gets its energy ; by (only) eating plants ; 2 7(a)(iv) photosynthesis ; 1 7(b) (membrane) controls the movement of substances in and out of the cells ; provides support ; 2

This question in 0653/33 Oct/Nov 2021

7 Fig. 7.1 is a photograph of a butterfly feeding on a lavender flower. Fig. 7.1 (a) Table 7.1 shows information about some of the structures of the lavender flower. Complete Table 7.1. Table 7.1 structure function anther … structure where pollen is transferred to during pollination … sepals … [3] (b) Read the information in Fig. 7.2. • The butterfly feeds on the lavender. • Frogs eat butterflies. • Snakes eat frogs. • Eagles eat snakes. Fig. 7.2 Construct a food chain using the information in Fig. 7.2. … [2] (c) Lavender plants photosynthesise. Describe the process of photosynthesis. … … … … … [3] [Total: 8]

8 marks

Mark scheme: 7(a) (anther) – produce pollen ; stigma ; (sepals) – protect (developing) flower / bud ; 3 Question Answer Marks 7(b) lavender → butterfly → frog → snake → eagle ;; one mark for correct order one mark for arrows in correct direction 2 7(c) uses water and carbon dioxide ; makes glucose / makes carbohydrates and oxygen ; needs light and chlorophyll ; 3

This question in 0653/32 Feb/March 2022

7 (a) Fig. 7.1 shows part of a food web from the ocean. orca leopard seal emperor penguin fish squid krill phytoplankton Fig. 7.1 (i) Phytoplankton are producers. Define the term producer. … … [2] (ii) Identify a primary consumer in Fig. 7.1. … [1] (iii) Identify two organisms eaten by emperor penguins in Fig. 7.1. 1 … 2 … [1] (iv) Orcas also eat fish. Draw one arrow on Fig. 7.1 to show this feeding relationship. [1] (b) Fig. 7.2 shows part of the carbon cycle. carbon dioxide in atmosphere P animal plant respiration respiration feeding dead organisms and waste products Q fossils and fossil fuels Fig. 7.2 (i) Identify processes P and Q in Fig. 7.2. P … Q … [2] (ii) Deforestation increases the concentration of carbon dioxide in the atmosphere. List two other undesirable effects of deforestation. 1 … 2 … [2] [Total: 9]

9 marks

Mark scheme: 7(a)(i) organism that makes its own (organic) nutrients ; using energy from, (sun)light / photosynthesis ; 2 7(a)(ii) krill ; 1 7(a)(iii) any two from: fish krill squid ; 1 7(a)(iv) arrow drawn from fish to orca ; 1 7(b)(i) P – combustion Q – fossilisation 2 7(b)(ii) any two from: soil erosion ; habitat loss ; extinction / endangers species ; flooding ; 2

This question in 0653/31 May/June 2022

7 (a) Fig. 7.1 shows information about four organisms living in an ocean habitat. • Krill eat microscopic producers called phytoplankton. • Fish eat krill. • Penguins eat fish. Fig. 7.1 (i) Construct a food chain using the information in Fig. 7.1. … [2] (ii) Identify the herbivore in Fig. 7.1. … [1] (b) Fig. 7.2 shows a photomicrograph of phytoplankton. chloroplasts containing chlorophyll Fig. 7.2 Explain why phytoplankton need chlorophyll. … … … [2] (c) Food is digested in the alimentary canal. Fig. 7.3 shows some of the pathway taken by food in the human alimentary canal. Complete Fig. 7.3. mouth oesophagus … small intestine … anus Fig. 7.3 [2] [Total: 7]

7 marks

Mark scheme: 7(a)(i) 2 7(a)(ii) krill ; 1 7(b) any two of: to absorb light energy; for photosynthesis ; to make carbohydrates ; 2 7(c) stomach ; large intestine ; 2

This question in 0653/32 May/June 2022

4 (a) Fig. 4.1 is a photograph of an insect‑pollinated flower. Y X Fig. 4.1 State the functions of the parts labelled X and Y in Fig. 4.1. X … Y … [2] (b) Seeds need a suitable temperature to germinate. State two other environmental conditions needed for germination. 1 … 2 … [2] (c) Plants transport water from their roots to their leaves. Water enters the root through root hair cells. (i) Water then passes into cells inside the root. Circle the correct name of these cells inside the root. cortex mesophyll phloem xylem [1] (ii) Water travels up the stem and evaporates from the surface of cells in the leaf. Circle the correct name of these cells in the leaf. cortex mesophyll phloem xylem [1] (d) Nutrients from the soil also enter plants through their roots. The pH of the soil affects the availability of nutrients. Fig. 4.2 provides data on the effect of soil pH on the availability of six nutrients. The bars show the range of soil pH for which the availability of each nutrient is maximum. 10.0 9.0 8.0 soil pH 7.0 6.0 5.0 4.0 calcium iron magnesium nitrate phosphate potassium ions ions ions ions maximum availability of nutrient Fig. 4.2 The availability of calcium is maximum in soils with a pH between 7.0 and 8.0. (i) Identify the nutrient in Fig. 4.2 that has maximum availability in a soil of pH 5.5. … [1] (ii) Use Fig. 4.2 to identify the range of soil pH for which the availability of nitrate ions is maximum. Place a tick (✓) in one box to show the correct answer. pH 4.0–6.0 pH 5.0–7.0 pH 6.0–8.0 pH 7.0–9.0 [1] (iii) Plants grown in soils with a pH of 5.0 may have yellow leaves. Complete the sentences to explain why: Plants need magnesium ions to make … . Soils with a pH of 5.0 do not have … availability of magnesium ions. [2] [Total: 10]

10 marks

Mark scheme: 4(a) X produce / release, pollen ; 2 Y attract insects (for pollination) ; 4(b) (presence of) water ; 2 (presence of) oxygen ; 4(c)(i) cortex ; 1 4(c)(ii) mesophyll ; 1 4(d)(i) iron ; 1 4(d)(ii) pH 6.0–8.0 ; 1 4(d)(iii) chlorophyll ; 2 maximum ;

This question in 0653/32 Oct/Nov 2022

7 (a) Fig. 7.1 is a diagram of two guard cells surrounding an open stoma from a plant leaf. stoma guard cell Fig. 7.1 (i) Draw a label line and the letter C to identify one chloroplast in Fig. 7.1. [1] (ii) Complete these sentences about guard cells and photosynthesis. Choose words from the list. Each word or phrase may be used once, more than once or not at all. carbon dioxide epidermis evaporation mesophyll nitrogen osmosis oxygen palisade transpiration Guard cells are found in the lower … of the leaf. The stomata are pores that allow the gas needed for photosynthesis to enter. This gas is called … . Water vapour diffuses out of the stomata during the process of … . [3] (b) Fig. 7.2 shows a food chain from a forest. green plants deer tiger Fig. 7.2 (i) Place ticks (✓) in all the boxes that describe the tiger. carnivore herbivore primary consumer secondary consumer tertiary consumer [2] (ii) State the name of the type of organism that gets its energy from waste organic matter. … [1] (c) Deforestation has undesirable effects on the animals in a food chain. Suggest two undesirable effects on the animals. 1 … 2 … [2] [Total: 9]

9 marks

Mark scheme: 7(a)(i) any chloroplast labelled ; 1 7(a)(ii) epidermis ; 3 carbon dioxide ; transpiration ; 7(b)(i) carnivore ; 2 secondary consumer ; 7(b)(ii) decomposer ; 1 7(c) any two from: 2 loss of habitat ; loss of food ; (possible) extinction / species may become endangered ;

This question in 0653/32 Feb/March 2023

7 (a) The leaves of some plants have green and white areas. Only the green areas of the leaf contain chlorophyll. Fig. 7.1 shows a green and white leaf. white green Fig. 7.1 Glucose from photosynthesis is stored as starch where it is made. The leaf in Fig. 7.1 is tested for the presence of starch using iodine solution. Fig. 7.2 shows some possible results. blue-black yellow-brown yellow-brown white green green blue-black blue-black P Q R S Fig. 7.2 (i) Identify the letter of the correct result of the starch test in Fig. 7.2. Give a reason for your answer. letter … reason … … … [2] (ii) State the mineral ion needed by plants to keep leaves green. … [1] (b) Transpiration involves the loss of water from leaves. Tick (3) two correct statements about transpiration. Water evaporates from the surface of mesophyll cells. Water evaporates from the surface of cortex cells. Water evaporates from the surface of stomata. Water vapour diffuses through mesophyll cells. Water vapour diffuses through cortex cells. Water vapour diffuses through stomata. [2] (c) The information in Fig. 7.3 describes some feeding relationships of living organisms in a habitat. • caterpillars eat flowers • owls eat snakes • frogs eat caterpillars • snakes eat frogs Fig. 7.3 (i) Draw a food chain using all the living organisms in Fig. 7.3. … [2] (ii) Identify the tertiary consumer in Fig. 7.3. … [1] (d) Two characteristics of living organisms are nutrition and respiration. State two other characteristics of living organisms. 1 … 2 … [2] [Total: 10]

10 marks

Mark scheme: 7(a)(i) R ; then any one from: chlorophyll is needed for photosynthesis ; (iodine) solution turns blue-black when starch is present ; (iodine) solution remains yellow-brown when starch is absent ; 7(a)(ii) magnesium (ions) ; 1 Question Answer Marks 7(b) Water evaporates from the surface of mesophyll cells.  Water evaporates from the surface of cortex cells. Water evaporates from the surface of stomata. Water vapour diffuses through mesophyll cells. Water vapour diffuses through cortex cells. Water vapour diffuses through stomata.  ;; 2 7(c)(i) flower(s)  caterpillar(s)  frog(s)  snake(s)  owl(s) ;; one mark for correct order one mark for correct arrows 2 7(c)(ii) snake ; 1 7(d) any two from: movement ; growth ; sensitivity ; reproduction ; excretion ; 2

This question in 0653/31 May/June 2023

7 (a) Fig. 7.1 shows an incomplete food web. bluefish anchovy crab shrimp mussel algae Fig. 7.1 (i) The bluefish eats the anchovy and the shrimp. Draw two arrows on Fig. 7.1 to show these feeding relationships. [1] (ii) Identify one primary consumer shown in Fig. 7.1. … [1] (iii) State the principal source of energy in all food webs. … [1] (b) Algae reproduce both sexually and asexually. State two ways asexual reproduction is different from sexual reproduction. 1 … … 2 … … [2] (c) Bluefish are eaten by humans. They are a source of fats. (i) State the dietary importance of fats in humans. … [1] (ii) Circle the name of the chemical used in the test for the presence of fats in food. Benedict’s solution biuret solution ethanol iodine solution [1] (iii) Fats are digested in the alimentary canal. Complete the sentences to describe the process of digestion. Digestion is the breakdown of … insoluble food molecules into … soluble molecules using mechanical and chemical processes. Chemical digestion uses a type of protein that functions as a biological catalyst. These proteins are called … . [2] [Total: 9]

9 marks

Mark scheme: 7(a)(i) arrow from anchovy to bluefish AND from shrimp to bluefish ; 1 7(a)(ii) shrimp / mussel ; 1 Question Answer Marks 7(a)(iii) the Sun ; 1 7(b) any two from: genetically identical offspring ; one parent / does not need two parents / does not need male and female parents ; no fertilisation / no fusion of nuclei / no fusion of gametes / no gametes involved ; 2 7(c)(i) for insulation / energy store / energy source ; 1 7(c)(ii) ethanol ; 1 7(c)(iii) (gap one) large AND (gap two) small ; enzymes ; 2

This question in 0653/32 May/June 2023

7 (a) Fig. 7.1 shows part of a food web. hawk bear grouse chipmunk marmot insects seeds grasses Fig. 7.1 (i) Identify the two herbivores in Fig. 7.1. … and … [1] (ii) Identify one tertiary consumer in Fig. 7.1. … [1] (b) Complete the sentences about producers. Use words from the list. Each word may be used once, more than once or not at all. carbon dioxide magnesium nitrate oxygen photosynthesis respiration iodine transpiration Producers make their own organic nutrients using the process of … . The raw materials needed for this process are water and … . The products of this process are glucose and … . Plants also need … ions for making amino acids. [4] (c) Food webs are affected by deforestation. Fig. 7.2 is a bar chart showing the area of deforestation each year for one country. 30,000 25,000 20,000 area of deforestation 15,000 each year / km2 10,000 5,000 0 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 year Fig. 7.2 Describe the trends shown in Fig. 7.2. … … … [2] [Total: 8]

8 marks

Mark scheme: 7(a)(i) insects and marmot ; 1 7(a)(ii) hawk / bear ; 1 7(b) photosynthesis ; carbon dioxide ; oxygen ; nitrate ; 4 7(c) the area of deforestation decreases then increases ; identifies lowest point is in 2012 / overall the decrease is greater than the increase / decreases to 4500 km2 (pa) ; 2

This question in 0653/33 May/June 2023

7 (a) Fig. 7.1 shows a food web. alligator raccoon heron frog carp mosquito bladderwort orchid Fig. 7.1 (i) The food web is not complete. The heron eats the carp. The alligator eats the heron. Draw two arrows on Fig. 7.1 to show these feeding relationships. [1] (ii) State the name of one producer shown in Fig. 7.1. … [1] (iii) Complete the sentences about the food web in Fig. 7.1. The mosquito eats the orchid. The mosquito is a … consumer. The frog eats the mosquito. The frog is a secondary consumer. The raccoon eats the frog. The raccoon is a … consumer. [2] (b) All living organisms respire. State the word equation for aerobic respiration. … [2] (c) (i) Fig. 7.2 shows some of the pathway taken by food in the human alimentary canal. Complete Fig. 7.2. mouth … stomach … large intestine anus Fig. 7.2 [2] (ii) Circle the function of the anus. absorption digestion egestion ingestion [1] [Total: 9]

9 marks

Mark scheme: 7(a)(i) arrows from carp to heron AND from heron to alligator ; 1 7(a)(ii) bladderwort / orchid ; 1 7(a)(iii) primary ; 2 tertiary ; 7(b) glucose + oxygen ; 2 → carbon dioxide + water ; 7(c)(i) oesophagus ; 2 small intestine ; 7(c)(ii) egestion ; 1

This question in 0653/31 Oct/Nov 2023

4 (a) Fig. 4.1 shows a food web for one ecosystem. bear hawk shrew songbird caterpillar plants Fig. 4.1 (i) Identify the herbivore in Fig. 4.1. … [1] (ii) Complete the sentences to explain why the hawk is a tertiary consumer. Use one word in each gap. The hawk eats an organism called a … . This organism is a … consumer. [2] (iii) Rabbits are also found in the ecosystem. Rabbits feed on plants. Bears eat rabbits. Construct a food chain to show this feeding relationship. … [2] (b) Some plants are pollinated by insects. (i) Define the term pollination. … … … [2] (ii) State the function of petals in pollination. … [1] (c) Complete the sentences about fertilisation in humans. Choose words from the list. gamete ovary oviduct ovum uterus zygote Fertilisation in humans takes place in the … of the female. After fertilisation, the fertilised egg is called the … . [2] [Total: 10]

10 marks

Mark scheme: 4(a)(i) caterpillar ; 1 4(a)(ii) songbird / shrew ; 2 secondary ; 4(a)(iii) plants → rabbits → bears 2 correct order ; correct arrows ; 4(b)(i) transfer of pollen (grains) ; 2 from anther to stigma ; 4(b)(ii) (petals) attract insects ; 1 4(c) oviduct ; 2 zygote ;

This question in 0653/32 Oct/Nov 2023

4 (a) Fig. 4.1 shows a food web for one ecosystem. bear hawk shrew songbird caterpillar plants Fig. 4.1 (i) Identify the herbivore in Fig. 4.1. … [1] (ii) Complete the sentences to explain why the hawk is a tertiary consumer. Use one word in each gap. The hawk eats an organism called a … . This organism is a … consumer. [2] (iii) Rabbits are also found in the ecosystem. Rabbits feed on plants. Bears eat rabbits. Construct a food chain to show this feeding relationship. … [2] (b) Some plants are pollinated by insects. (i) Define the term pollination. … … … [2] (ii) State the function of petals in pollination. … [1] (c) Complete the sentences about fertilisation in humans. Choose words from the list. gamete ovary oviduct ovum uterus zygote Fertilisation in humans takes place in the … of the female. After fertilisation, the fertilised egg is called the … . [2] [Total: 10]

10 marks

Mark scheme: 4(a)(i) caterpillar ; 1 4(a)(ii) songbird / shrew ; 2 secondary ; 4(a)(iii) plants → rabbits → bears 2 correct order ; correct arrows ; 4(b)(i) transfer of pollen (grains) ; 2 from anther to stigma ; 4(b)(ii) (petals) attract insects ; 1 4(c) oviduct ; 2 zygote ;

This question in 0653/33 Oct/Nov 2023

7 (a) Fig. 7.1 shows part of the carbon cycle. carbon dioxide in the atmosphere process process C A process C carbon in carbon in animals plants process B Fig. 7.1 (i) Identify process B shown in Fig. 7.1. … [1] (ii) Complete the word equation for process A shown in Fig. 7.1. carbon dioxide + … … + … [2] (iii) The combustion of fossil fuels has an effect on the carbon cycle. Tick (3) one box that describes an undesirable effect of combustion. less carbon is available for animals the rate of food production in plants decreases the carbon dioxide concentration in the atmosphere increases more carbon is available for plants [1] (b) Fig. 7.2 shows some feeding relationships between plants and animals on the African Savanna. lion African wild dog gazelle zebra tree Fig. 7.2 (i) State the name of the type of diagram shown in Fig. 7.2. … [1] (ii) Use Fig. 7.2 to identify one carnivore and one tertiary consumer. carnivore … tertiary consumer … [2] (iii) Lions eat gazelles. Draw one arrow on Fig. 7.2 to show this relationship. [1] (c) Trees grow from seeds. One environmental condition needed for the successful germination of seeds is a suitable temperature. State one other environmental condition needed for germination. … [1] [Total: 9]

9 marks

Mark scheme: 7(a)(i) feeding ; 1 7(a)(ii) water ; 2 glucose + oxygen ; 7(a)(iii) 1 less carbon is available for animals the rate of food production in plants decreases the carbon dioxide concentration in the atmosphere increases ✓ ; more carbon is available for plants 7(b)(i) food web ; 1 7(b)(ii) carnivore: (African wild) dog / lion ; 2 tertiary consumer: lion ; 7(b)(iii) arrow drawn from gazelle pointing towards lion ; 1 7(c) oxygen / water / moisture ; 1

This question in 0653/32 Feb/March 2024

4 (a) Fig. 4.1 shows the pathway taken by water through a plant root. xylem in the stem leading to the leaf soil particle water Q root hair cell NOT TO Key SCALE direction of movement of water Fig. 4.1 (i) State the name of the type of cells labelled Q in Fig. 4.1. … [1] (ii) On Fig. 4.1, draw a label line and the letter V to identify one vacuole. [1] (iii) Complete the sentences to describe the pathway taken by water through the leaf. Choose words from the list. Each word may be used only once. diffusion evaporation osmosis transmission transpiration Water moves from the xylem to the air spaces in the leaf by ……………………………………………… from the surface of mesophyll cells. The water vapour then passes out of the stomata by the process of This loss of water vapour from the leaves is called [3] (b) Fig. 4.2 shows a plant reproducing asexually. parent plant offspring Fig. 4.2 Tick (✓) two correct statements about the plants shown in Fig. 4.2. The offspring are genetically identical to the parent plant. The offspring developed from germinating seeds. The parent plant needed flowers to produce the offspring. Fertilisation did not take place to produce the offspring. The parent plant has been pollinated to produce the offspring. [2] (c) (i) Explain why plants are classified as producers in a food chain. … … … [2] (ii) Fig. 4.3 shows a food chain. Circle the primary consumer in Fig. 4.3. Fig. 4.3 [1] [Total: 10]

10 marks

Mark scheme: 4(a)(i) (root) cortex ; 1 4(a)(ii) one vacuole labelled in any cell ; 1 4(a)(iii) evaporation ; diffusion ; transpiration ; 3 4(b) The offspring are genetically identical to the parent plant. ; Fertilisation did not take place to produce the offspring. ; three ticks two correct = 1 mark three ticks one correct = 0 marks more than three ticks = 0 2 Question Answer Marks 4(c)(i) (plants) make their own, food / glucose / sugar ; by photosynthesis / using the energy from (sun)light / using light energy ; 2 4(c)(ii) grasshopper (circled) ; 1

This question in 0653/31 May/June 2024

7 (a) Fig. 7.1 describes the feeding relationships in one food chain. • robins are small birds that eat caterpillars • caterpillars are primary consumers • a merlin is a large bird that eats robins • the producer in the food chain is an oak tree Fig. 7.1 (i) Draw the food chain using the names of all the organisms in Fig. 7.1. … [2] (ii) Using the information in Fig. 7.1, identify all the organisms that are: herbivores … carnivores. … [2] (b) Fig. 7.2 shows part of the carbon cycle. carbon dioxide in atmosphere photosynthesis B A B decomposition carbon in organic compounds in producers death carbon in dead organic matter feeding egestion C fossil fuels Fig. 7.2 State the name of the processes labelled A, B and C. A … B … C … [3] [Total: 7]

7 marks

Mark scheme: 7(a)(i) oak / tree → caterpillar → robin → merlin ;; named organisms in correct order (1) arrows correct (1) 2 7(a)(ii) caterpillar ; robin and merlin ; 2 Question Answer Marks 7(b) A combustion ; B respiration ; C fossilisation ; 3

This question in 0653/32 May/June 2024

4 (a) Fig. 4.1 shows some of the parts of an insect-pollinated flower. F A E B D C Fig. 4.1 (i) State the letter on Fig. 4.1 that identifies: an ovule … where pollination occurs. … [2] (ii) Fig. 4.1 does not show the sepals and petals of the flower. State the function of: sepals … petals. … [2] (b) An animal gets its energy by eating only plants. State the term that describes this type of animal. … [1] (c) Plants use carbon dioxide for photosynthesis. (i) Complete the word equation for photosynthesis. carbon dioxide +  + oxygen [2] (ii) Fig. 4.2 is a graph showing the effect of carbon dioxide concentration on the rate of photosynthesis. 25 20 rate of 15 photosynthesis in arbitrary 10 units 5 0 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 percentage concentration of carbon dioxide in the air Fig. 4.2 Describe the effect of increasing carbon dioxide concentration on the rate of photosynthesis shown in Fig. 4.2. Include data in your answer. … … … … [2] (d) Deforestation causes an increase in carbon dioxide concentration in the atmosphere. State two other undesirable effects of deforestation. 1 … 2 … [2] [Total: 11]

11 marks

Mark scheme: 4(a)(i) C ; F ; 2 4(a)(ii) protect, bud / flower ; attract, insects / pollinators ; 2 4(b) herbivore ; 1 4(c)(i) water ; glucose ; 2 4(c)(ii) (rate of photosynthesis) increases then levels off ; use of data, e.g. maximum rate = 18 (arbitrary units) / stops increasing at 0.07 (%) ; 2 Question Answer Marks 4(d) any two from: habitat destruction ; disrupts food chain ; extinction ; loss of soil ; flooding ; 2

This question in 0653/33 May/June 2024

1 (a) Fig. 1.1 shows the flower of a plant. X sepal Y ovary Fig. 1.1 (i) State the name of the part labelled X on Fig. 1.1. … [1] (ii) State the name and function of the part labelled Y on Fig. 1.1. name … function … [2] (iii) Complete the description of what happens in the ovary of the flower. The ovary is where the process of … takes place. The nucleus of a … grain fuses with the nucleus of an … . [3] (b) Fig. 1.2 shows a food web. eagle thrush frog dragonfly grasshopper butterfly corn a flowering plant Fig. 1.2 Table 1.1 shows some terms that can be used to describe some of the organisms in Fig. 1.2. Tick (✓) the boxes in Table 1.1 to show all the terms used to describe each organism. Table 1.1 organism carnivore herbivore primary consumer producer butterfly corn thrush [3] [Total: 9]

9 marks

Mark scheme: Question Answer Marks 1(a)(i) anther ; 1 1(a)(ii) petal ; 2 attract (named) pollinators ; 1(a)(iii) fertilisation ; 3 pollen ; ovule ; 1(b) 3 organism carnivore herbivore primary consumer producer butterfly ✓ ✓ corn ✓ thrush ✓ butterfly row correct ; corn row correct ; thrush row correct ;

This question in 0653/31 Oct/Nov 2024

7 Plants manufacture carbohydrates by the process of photosynthesis. The carbohydrates are then stored as starch in the leaves. (a) Three plants of the same type, A, B and C, are placed in different conditions. After two days, a leaf from each plant is tested with iodine solution. Table 7.1 shows the results. Table 7.1 plant conditions colour of iodine solution A carbon dioxide available but no light orange B carbon dioxide and light available blue-black C light available but no carbon dioxide orange (i) Explain why the result for plant B is different from the results for plants A and C. … … … … [2] (ii) Plants need chlorophyll for photosynthesis. Circle the mineral ion needed by plants for making chlorophyll. calcium magnesium potassium sodium zinc [1] (iii) Water is a raw material for photosynthesis. Complete these sentences about the movement of water in a plant. • Water enters the roots through root … cells. • Water is transported from the roots to the leaves in … vessels. • Water is then lost from the leaves through pores (holes) called … . [3] (b) Plants are the producers in a food chain. Fig. 7.1 shows information about organisms in one food chain. • butterflies feed on parts of flowers • frogs eat the butterflies • herons eat the frogs Fig. 7.1 (i) Construct a food chain using all the organisms in Fig. 7.1. … [2] (ii) Identify the primary consumer in Fig. 7.1. … [1] [Total: 9]

9 marks

Mark scheme: 7(a)(i) any two from: 2 blue-black shows the presence of starch / only one where starch was made ; only plant B had both carbon dioxide and light (needed for photosynthesis) ; 7(a)(ii) magnesium ; 1 7(a)(iii) hair ; 3 xylem ; stomata ; 7(b)(i) flowers → butterflies → frogs → herons 2 correct order of all organisms ; correct arrows ; 7(b)(ii) butterflies ; 1

This question in 0653/32 Oct/Nov 2024

7 Plants manufacture carbohydrates by the process of photosynthesis. The carbohydrates are then stored as starch in the leaves. (a) Three plants of the same type, A, B and C, are placed in different conditions. After two days, a leaf from each plant is tested with iodine solution. Table 7.1 shows the results. Table 7.1 plant conditions colour of iodine solution A carbon dioxide available but no light orange B carbon dioxide and light available blue-black C light available but no carbon dioxide orange (i) Explain why the result for plant B is different from the results for plants A and C. … … … … [2] (ii) Plants need chlorophyll for photosynthesis. Circle the mineral ion needed by plants for making chlorophyll. calcium magnesium potassium sodium zinc [1] (iii) Water is a raw material for photosynthesis. Complete these sentences about the movement of water in a plant. • Water enters the roots through root … cells. • Water is transported from the roots to the leaves in … vessels. • Water is then lost from the leaves through pores (holes) called … . [3] (b) Plants are the producers in a food chain. Fig. 7.1 shows information about organisms in one food chain. • butterflies feed on parts of flowers • frogs eat the butterflies • herons eat the frogs Fig. 7.1 (i) Construct a food chain using all the organisms in Fig. 7.1. … [2] (ii) Identify the primary consumer in Fig. 7.1. … [1] [Total: 9]

9 marks

Mark scheme: 7(a)(i) any two from: 2 blue-black shows the presence of starch / only one where starch was made ; only plant B had both carbon dioxide and light (needed for photosynthesis) ; 7(a)(ii) magnesium ; 1 7(a)(iii) hair ; 3 xylem ; stomata ; 7(b)(i) flowers → butterflies → frogs → herons 2 correct order of all organisms ; correct arrows ; 7(b)(ii) butterflies ; 1

This question in 0653/33 Oct/Nov 2024

1 (a) Fig. 1.1 shows the main organs of the digestive system. E A D stomach C B Fig. 1.1 State the letter on Fig. 1.1 that identifies: the large intestine … the salivary gland. … [2] (b) Proteins are digested in the stomach. (i) Describe the importance of proteins as part of a balanced diet. … … [1] (ii) Circle the name of the smaller molecules that proteins are made from. amino acids glucose fatty acids glycerol [1] (c) Fig. 1.2 shows a food web that includes humans. eagle lizard snake fish dragonfly frog human mayfly phytoplankton Fig. 1.2 (i) Identify the food source for the human in Fig. 1.2. … [1] (ii) Identify the producer in Fig. 1.2. … [1] (iii) Explain why the frog in Fig. 1.2 is a carnivore. … … [1] (d) In some parts of the world, eagles are endangered. Suggest two reasons why eagles may become endangered. 1 … … 2 … … [2] [Total: 9]

9 marks

Mark scheme: Question Answer Marks 1(a) C ; 2 E ; 1(b)(i) needed for, growth / repair ; 1 1(b)(ii) amino acids ; 1 more than one answer circled = 0 marks 1(c)(i) fish ; 1 1(c)(ii) phytoplankton ; 1 1(c)(iii) (only) gains energy from animals ; 1 1(d) any two from: 2 climate change ; habitat destruction ; hunting ; introduced species ; overharvesting ; pollution (in environment) ; AVP, e.g. new disease ;

This question in 0653/32 Feb/March 2025

2 (a) Fig. 2.1 is a diagram of a cross-section through a leaf. Q P Fig. 2.1 (i) Name the part labelled P on Fig. 2.1. … [1] (ii) Draw a label line and the letter S to identify a spongy mesophyll cell on Fig. 2.1. [1] (iii) Name the pigment found in the part labelled Q on Fig. 2.1. … [1] (b) A plant is left in a warm dark room for three days. After three days, a leaf from the plant is tested with iodine solution. The iodine solution stays yellow-brown in colour. Complete the sentences to explain this result. The yellow-brown colour of the iodine solution indicates that the leaf does not contain … . The plant has not photosynthesised because there is no … . [2] (c) Fig. 2.2 shows part of a food web. kingfisher frog snake turtle dragonfly fish slug fly aquatic plant algae Fig. 2.2 (i) Identify one herbivore in Fig. 2.2. … [1] (ii) Identify one tertiary consumer in Fig. 2.2. … [1] (iii) Animals in the food web produce waste organic material. Name the type of organism that gets its energy from waste organic material. … [1] [Total: 8]

8 marks

Mark scheme: 2(a)(i) (lower) epidermis ; 1 2(a)(ii) any spongy mesophyll cell with label line S touching cell ; 1 2(a)(iii) chlorophyll ; 1 2(b) starch ; 2 light ; 2(c)(i) fly / fish / slug ; 1 2(c)(ii) frog ; 1 2(c)(iii) decomposer ; 1

This question in 0653/32 May/June 2025

3 Fig. 3.1 shows part of a food web from a coral reef habitat. shark parrotfish unicornfish coral zooplankton phytoplankton Fig. 3.1 (a) (i) Circle the word that describes the phytoplankton in the food web in Fig. 3.1. animal decomposer herbivore producer [1] (ii) Identify one primary consumer shown in Fig. 3.1. … [1] (iii) Explain why the shark shown in Fig. 3.1 is described as a carnivore. … … [1] (b) Coral is being damaged by marine pollution. (i) Use Fig. 3.1 to explain the effect this has on the number of parrotfish in the habitat. … … … [2] (ii) Pollution of freshwater and marine environments is one cause of habitat destruction. Describe one other cause of habitat destruction. … … [1] (c) Coral reef habitats release carbon dioxide into the atmosphere. State a process in the carbon cycle that removes carbon dioxide from the atmosphere. … [1] [Total: 7]

7 marks

Mark scheme: 3(a)(i) producer ; 1 3(a)(ii) zooplankton / unicornfish ; 1 3(a)(iii) feeds on / eats, animals / fish (only) ; 1 3(b)(i) (parrotfish) numbers would decrease ; 2 as less food available (for parrotfish) ; 3(b)(ii) any one from: 1 increased area for housing / crop production / livestock production ; extraction of natural material ; construction, e.g. building roads / building railways ; 3(c) photosynthesis ; 1

This question in 0653/33 May/June 2025

3 (a) Fig. 3.1 shows a food web. muskrat osprey mink duck brown trout tadpole caddis fly larva duckweed Fig. 3.1 (i) Identify in Fig. 3.1: one secondary consumer … the total number of carnivores. … [2] (ii) Identify the organism in Fig. 3.1 that gains energy from the mink. … [1] (b) Duckweed uses energy from light for photosynthesis. Choose words from the list to complete the sentences. Each word may be used once, more than once or not at all. brown chloroplasts decompose digest green mitochondria nuclei purple synthesise Photosynthesis is the process by which plants … carbohydrates. Photosynthesis in plants requires a … pigment. The pigment is found inside … . [3] (c) Carbohydrates are part of a balanced diet for humans. (i) List all the chemical elements that make up carbohydrates. … [1] (ii) State why carbohydrates are important in the body. … [1] (iii) State the component of blood that transports carbohydrates and other nutrients around the body. … [1] [Total: 9]

9 marks

Mark scheme: 3(a)(i) as (brown) trout / mink ; 2 4 ; 3(a)(ii) muskrat ; 1 3(b) synthesise ; 3 green ; chloroplasts ; 3(c)(i) carbon AND oxygen AND hydrogen ; 1 3(c)(ii) (needed) for energy ; 1 3(c)(iii) plasma ; 1

This question in 0653/31 Oct/Nov 2025

3 Tigers are endangered animals that live wild only in parts of Asia. Tigers catch and eat many different animals. (a) (i) Table 3.1 shows some information about the number of tigers that live wild. Table 3.1 estimated number of tigers year that live wild 1900 100 000 2000 3500 2020 4500 Suggest two reasons for the difference in the number of tigers between 1900 and 2000. 1 … 2 … [2] (ii) Circle all the words that describe the tiger. carnivore consumer decomposer herbivore producer [2] (b) Tigers are part of an ecosystem. (i) Circle two words in bold to give a correct description of an ecosystem. An ecosystem is a community of habitats / organisms and their climate / environment, interacting together. [1] (ii) State the word that describes the number of different species that live in an area. … [1] (c) Tigers have a similar alimentary canal to humans. The flow chart in Fig. 3.1 shows the direction that food moves as it passes through the alimentary canal. Complete Fig. 3.1. mouth … stomach … large intestine Fig. 3.1 [2] [Total: 8]

8 marks

Mark scheme: 3(a)(i) any two from: 2 • climate change ; • habitat destruction / deforestation ; • hunting ; • pollution ; 3(a)(ii) consumer ; 2 carnivore ; 3(b)(i) organisms AND environment circled ; 1 3(b)(ii) biodiversity ; 1 3(c) oesophagus ; 2 small intestine ;

This question in 0653/32 Oct/Nov 2025

3 Tigers are endangered animals that live wild only in parts of Asia. Tigers catch and eat many different animals. (a) (i) Table 3.1 shows some information about the number of tigers that live wild. Table 3.1 estimated number of tigers year that live wild 1900 100 000 2000 3500 2020 4500 Suggest two reasons for the difference in the number of tigers between 1900 and 2000. 1 … 2 … [2] (ii) Circle all the words that describe the tiger. carnivore consumer decomposer herbivore producer [2] (b) Tigers are part of an ecosystem. (i) Circle two words in bold to give a correct description of an ecosystem. An ecosystem is a community of habitats / organisms and their climate / environment, interacting together. [1] (ii) State the word that describes the number of different species that live in an area. … [1] (c) Tigers have a similar alimentary canal to humans. The flow chart in Fig. 3.1 shows the direction that food moves as it passes through the alimentary canal. Complete Fig. 3.1. mouth … stomach … large intestine Fig. 3.1 [2] [Total: 8]

8 marks

Mark scheme: 3(a)(i) any two from: 2 • climate change ; • habitat destruction / deforestation ; • hunting ; • pollution ; 3(a)(ii) consumer ; 2 carnivore ; 3(b)(i) organisms AND environment circled ; 1 3(b)(ii) biodiversity ; 1 3(c) oesophagus ; 2 small intestine ;

This question in 0653/33 Oct/Nov 2025