Transpiration — Paper 3 · IGCSE Science - Combined 0653

7 Transpiration occurs when water vapour is lost from the leaves of plants through the stomata. (a) Describe the path taken by water in the plant from the soil to the leaves. … … … … [3] (b) A student carries out an experiment to investigate the rate of transpiration in a leafy shoot. Fig. 7.1 shows the apparatus he uses. leafy shoot reservoir grease water scale (cm) 5 4 3 2 1 0 air bubble bubble moves in this direction Fig. 7.1 Transpiration from the leafy shoot causes water to be taken into the shoot from the apparatus and the air bubble moves to the left. The faster the rate of transpiration, the faster the air bubble moves. The student uses the apparatus to do three tests in different conditions. The average distances moved by the air bubble in one minute are shown in Table 7.1. Table 7.1 average distance moved by test number conditions the bubble in one minute / cm 1 on the laboratory bench 1.2 on the same bench with a lamp 2 2.8 shining next to the apparatus 3 in a crowded classroom (i) State two reasons to explain why the air bubble moved more quickly in test 2 compared with test 1. 1. … … … 2. … … … [3] (ii) For test 3 the student takes the apparatus into a crowded classroom. There is an increase in the humidity of the air in the classroom. Suggest a value for the average distance moved by the air bubble in one minute in the crowded classroom. value = … cm / minute Explain your answer. … … … … [2]

8 marks

Mark scheme: 7(a) water enters / taken up by root ; root hair cells ; up stem (to leaves) ; through xylem ; [max3] 7(b)(i) heat produced by lamp ; increases transpiration rate ; increased light intensity; increases transpiration rate ; 3 7(b)(ii) any suitable value less than 1.2 (cm) ; increased humidity reduces the rate of transpiration ; 2

This question in 0653/32 Feb/March 2017

7 Fig. 7.1 shows a sealed glass jar containing soil and plants. An oxygen sensor is used to find out how the concentration of oxygen in the glass jar changes during the day. The plants can live in the glass jar for several weeks without opening the jar. bung oxygen sensor glass jar soil Fig. 7.1 (a) The plants in Fig. 7.1 produce oxygen during photosynthesis. Complete the word equation for photosynthesis. light + + oxygen chlorophyll [2] (b) Fig. 7.2 shows a graph of the oxygen concentration in the glass jar shown in Fig. 7.1 over a 12-hour period on a sunny day. oxygen concentration 06.00 08.00 10.00 12.00 14.00 16.00 18.00 time / hours Fig. 7.2 (i) State a time when the rate of photosynthesis is highest. Explain your answer. time … explanation … … … [2] (ii) On a different day the graph follows a similar pattern until 10.00 hours. After 10.00 hours the weather changes and it becomes darker. This affects the concentration of oxygen in the glass jar. On Fig. 7.2, add the letter X to show a possible value for oxygen concentration at 14.00 hours. Explain your answer. … … … [2] (c) Water is lost as water vapour from leaves by transpiration. On a very warm day the concentration of water vapour in the air in the glass jar increases. Describe the effect of this increase in water vapour on the rate of transpiration from the plants in the glass jar. … … … [1]

7 marks

Mark scheme: 7(a) carb → su 7(b)(i) any max bon dioxide + wa ugar / glucose ; time between 10 ximum rate of ox ater ; 0.00 and 13.00 ygen production ; n / gradient of gra aph is steep(est ) ; 2 2 Question Answer Marks 7(b)(ii) letter X drawn at 14.00 anywhere below line graph ; (rate of) photosynthesis (oxygen production) dependent on (amount of) light ; 2 7(c) reduces / causes less / prevents transpiration ; 1

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

1 (a) Use the following words or phrases to complete the flow chart about a possible pathway taken by water through a plant from the soil to the air. Each word or phrase may be used once, more than once or not at all. cuticle epidermal cells mesophyll cells phloem root hair cells stomata tubes xylem from the soil into the root through the … in the stem into the cells in the leaf evaporation from surfaces of the … inside the leaf through the … into the air [3] (b) State two functions of water in plants. 1. … 2. … [2] (c) A supply of water is needed by humans too. Most of the plasma in the blood is made up from water. The plasma carries the blood cells around the body. State two other substances that are transported by the plasma. 1. … 2. … [2] (d) The haemoglobin in red blood cells contains iron. (i) State the role of haemoglobin in the blood. … [1] (ii) Explain why a menstruating woman needs to make sure she takes enough iron in her diet. … … [1] (iii) Describe one symptom of iron deficiency in the body. … … [1]

10 marks

Mark scheme: 1(a) xylem ; mesophyll cells ; stomata ; 3 1(b) any two from photosynthesis ; transport of ions ; support / turgor ; AVP ; max 2 1(c) ions / named ion ; soluble nutrients / named soluble nutrient ; hormones / named hormone ; carbon dioxide ; AVP ; max 2 1(d)(i) transport of oxygen ; 1 1(d)(ii) to replace iron lost during menstruation / period ; 1 1(d)(iii) feeling tired / dizzy ; 1

This question in 0653/33 Oct/Nov 2017

7 Fig. 7.1 shows some processes occurring in a forest growing on a hill. clouds water vapour X tree leaves fall onto the soil surface of soil roots Fig. 7.1 (a) Name the process labelled X. … [1] (b) (i) The leaves of the trees contain carbohydrates, for example sugar. Describe how leaves use a carbon compound in the air to make sugar. … … … [2] (ii) When leaves die they fall onto the soil. Decomposers (bacteria and fungi) feed on the dead leaves and use the sugar present in the leaves. Suggest and explain how the carbon in the sugar is returned to the atmosphere by the decomposers. … … … [2] (c) The trees in the forest shown in Fig. 7.1 are cut down. Predict and explain the effect of clearing the trees on the amount of rain falling on the area. … … … [1] (d) A storm occurs higher up the hill and water comes flowing down the hill. Suggest how the soil in the cleared area will be affected by water from heavy rainfall flowing down the hill. Explain your answer. … … … [2]

8 marks

Mark scheme: 7(a) transpiration ; 1 7(b)(i) carbon dioxide from the air ; is used in photosynthesis / reacts with water ; 2 7(b)(ii) by respiration ; carbon dioxide released ; 2 7(c) rainfall reduced (no mark) less water being transpired / evaporated from trees ; 1 7(d) soil easily eroded ; due to lack of tree roots ; 2

This question in 0653/33 Oct/Nov 2017

7 (a) Fig. 7.1 shows cross-sections through a root and a stem of a flowering plant. A B Fig. 7.1 (i) State which diagram, A or B, represents the root. Give two reasons for your answer. The root is diagram … reason 1 … … reason 2 … … [2] (ii) On diagram B, in Fig. 7.1, shade in one area where the xylem is found. [1] (b) Use the words or phrases to complete the sentences about transpiration. Each word may be used once, more than once or not at all. cuticle diffuses dissolves guard cells higher lower mesophyll cells stomata similar xylem Water evaporates from the surfaces of … inside the leaf. This gives the air inside the leaf a … concentration of water vapour than the atmosphere. As a result the water vapour … out of the leaves through tiny holes called the … . [4] (c) Water is one of the raw materials for photosynthesis. Complete the word equation for photosynthesis. water + + [2]

9 marks

Mark scheme: 7(a)(i) A no mark presence of root hairs ; xylem / phloem / vascular tissue (stele) found in the central area ; 2 7(a)(ii) one area of xylem correctly shaded in B ; 1 7(b) mesophyll cells ; higher ; diffuses ; stomata ; 4 7(c) carbon dioxide ; sugar / glucose + oxygen ; 2

This question in 0653/32 Oct/Nov 2018

4 (a) Fig. 4.1 shows a cross-section of a leaf as viewed under a microscope. chloroplasts phloem Fig. 4.1 (i) Complete the labels on Fig. 4.1, using words from the list. cuticle guard cell palisade cell stomata upper epidermis xylem [2] (ii) State the function of a chloroplast. … … [1] (iii) State the function of phloem. … … [1] (b) The leaf of a plant produces glucose. (i) Plants and animals use glucose to make two different larger molecules for storage. Name one of these larger molecules. … [1] (ii) Glucose is needed by plants and animals for growth. Complete the sentence to define the term growth. Growth is defined as a … increase in size. [1] (iii) Glucose is a carbohydrate. List the three chemical elements that make up carbohydrates. 1 … 2 … 3 … [1] (c) The leaf of a plant needs water for photosynthesis. The statements show the pathway taken by water from the soil to the leaf. The statements are not in the correct order. Use numbers 1 to 5 to show the correct order. The third statement has been identified. lost through the stomata as water vapour enters mesophyll cells of leaf passes through root cortex cells passes into xylem 3 taken in by root hair cells [2] [Total: 9]

9 marks

Mark scheme: 4(a)(i) (top) xylem ; (bottom) guard cell ; 2 4(a)(ii) photosynthesis ; 1 4(a)(iii) transport sugars / transport sucrose ; 1 4(b)(i) starch / glycogen ; 1 4(b)(ii) permanent ; 1 4(b)(iii) carbon AND hydrogen AND oxygen ; 1 4(c) lost through the stomata as water vapour 5 enters mesophyll cells of leaf 4 passes though root cortex cells 2 passes into xylem (3) taken in by root hair cells 1 ;; all correct = 2 marks any two correct = 1 mark 2

This question in 0653/32 Feb/March 2020

1 (a) Fig. 1.1 shows red blood cells. Fig. 1.1 (i) State the function of red blood cells. … … [1] (ii) A component of the blood is needed to clot the blood. State the name of this component. … [1] (b) Fig. 1.2 shows a diagram of a different type of human blood cell. The diameter XY in the diagram of the cell is 30 mm. Y X Fig. 1.2 The actual diameter XY of the cell is 0.015 mm. Calculate the magnification of the cell shown in Fig. 1.2. magnification = … [2] (c) Water is transported to the cells of the body by the blood. Complete the sentence about movement of water into and out of cells. Water diffuses through a … permeable membrane by … . [2] (d) Water is also transported through plants. (i) Fig. 1.3 shows the pathway taken by water through the cells of a root. P Q R (takes water to the leaves) soil particles Fig. 1.3 Identify structures P, Q and R shown in Fig. 1.3. P … Q … R … [3] (ii) Transport of water in plants involves transpiration. State two factors that increase the rate of transpiration. 1. … 2. … [2] [Total: 11]

11 marks

Mark scheme: 1(a)(i) transport oxygen ; 1 1(a)(ii) platelets ; 1 1(b) = 30 / 0.015 ; = 2000 ; 2 1(c) partially ; osmosis ; 2 1(d)(i) P root hair (cell) ; Q root cortex (cell) ; R xylem ; 3 1(d)(ii) increased temperature ; decreased humidity ; 2

This question in 0653/32 May/June 2020

4 (a) Fig. 4.1 shows a cross-section of a plant stem as seen under a microscope. A D B C Fig. 4.1 (i) State the letter, A, B, C or D, that shows the position of xylem vessels in the plant stem in Fig. 4.1. … [1] (ii) Name the cells that transport sugar through the plant stem. … [1] (b) Use words from the list to complete the definition of transpiration. Each word may be used once, more than once, or not at all. absorption diffusion egestion evaporation fusion Transpiration is the loss of water vapour from plant leaves by … of water at the surface of the mesophyll cells followed by … of water vapour through the stomata. [2] (c) Fig. 4.2 shows a plant that has been next to a window for a few weeks. Fig. 4.2 (i) Name the tropic response shown by the plant in Fig. 4.2 that causes the plant to grow towards the light. … [1] (ii) The plant has flowers with pink petals. State the function of petals. … [1] (d) Some responses in humans are controlled by hormones. (i) Describe how hormones are transported to their target organs. … … … [2] (ii) Adrenaline is a hormone. Describe two effects of adrenaline on the body. 1 … … 2 … … [2] [Total: 10]

10 marks

Mark scheme: 4(a)(i) C ; 1 4(a)(ii) phloem ; 1 4(b) evaporation ; diffusion ; 2 4(c)(i) phototropism ; 1 4(c)(ii) to attract insects ; 1 Question Answer Marks 4(d)(i) any two from: in the blood ; in the plasma ; through, the circulatory system / (blood) vessels ; 2 4(d)(ii) any two from: increased, breathing rate / depth of breathing ; increased, pulse rate / heart rate ; widened pupils ; 2

This question in 0653/32 Oct/Nov 2020

4 (a) A student investigates water loss from the leaves of a plant. The student takes four leaves from the same plant and covers each leaf with petroleum jelly as described in Table 4.1. The petroleum jelly stops water loss from the leaves. The mass of each leaf is recorded and then the leaves are placed on a line for 48 hours as shown in Fig. 4.1. A B C D Fig. 4.1 After 48 hours the mass of each leaf is recorded again. Table 4.1 shows the results. Table 4.1 treatment with mass at start mass after 48 hours change in mass leaf petroleum jelly / g / g / g A both surfaces covered 3.2 3.2 0.0 B lower surface covered 3.3 3.2 0.1 C upper surface covered 3.4 2.8 0.6 D not covered 3.3 2.6 (i) Calculate the change in mass for leaf D. mass = … g [1] (ii) Explain why leaf C lost more mass than leaf B. Include ideas about stomata in your answer. … … … [2] (b) Water is transported from the roots to the leaves in the xylem vessels. Fig. 4.2 shows a cross-section of a root. Fig. 4.2 (i) Use a label line and the letter X to show the position of xylem vessels in Fig. 4.2. [1] (ii) Xylem vessels also transport mineral ions. State the name of the mineral ions needed to make amino acids. … [1] (c) A clinostat can be used to investigate tropic responses in plants. Fig. 4.3 shows a plant growing in a pot placed on its side (plant A) and a plant growing on a clinostat (plant B). The clinostat slowly turns plant B. rotating Clinostat plant A plant B Fig. 4.3 The plants are left to grow in these positions for one week. They receive plenty of light from all directions. (i) Complete the sentences to explain the results. Plant A grows upwards … from gravity. This response is called … . Plant B grows … because each side of the plant experiences the same gravitational force. [3] (ii) Responses in humans are controlled by chemical substances. Place a tick (✓) in one box to show a correct statement about these chemical substances. They are enzymes transported in red blood cells. They are enzymes transported in blood plasma. They are hormones transported in red blood cells. They are hormones transported in blood plasma. [1] [Total: 9]

9 marks

Mark scheme: 4(a)(i) 0.7 ; 1 4(a)(ii) any two from: water is lost from the stomata ; more stomata on lower surface (of leaves) ; more water is lost from the lower surface (of leaves) ; 2 4(b)(i) line drawn to cells at centre of root ; 1 4(b)(ii) nitrate ; 1 4(c)(i) away ; (negative) gravitropism ; horizontally ; 3 4(c)(ii) They are enzymes transported in red blood cells. They are enzymes transported in blood plasma. They are hormones transported in red blood cells. They are hormones transported in blood plasma.  ; 1

This question in 0653/32 May/June 2021

1 (a) A blue dye is dissolved in water to make a blue liquid. Fig. 1.1 shows a cut plant stem in a beaker of the blue liquid. leaves plant stem blue liquid Fig. 1.1 The plant stem is left in the blue liquid for 24 hours. (i) Complete the sentences to explain why the leaves turn blue. Choose words from the list. Each word may be used once, more than once or not at all. cortex mesophyll phloem root hair stomata xylem The blue liquid moves up the plant stem in vessels called … . In the leaves, the blue liquid moves out of the vessels into … cells. Water in the blue liquid then diffuses out of the … into the air. [3] (ii) Fig. 1.2 shows the cross-section of the plant stem from Fig. 1.1. A B C D Fig. 1.2 The blue liquid only stains the transport vessels in the stem blue. Identify the letter in Fig. 1.2 that shows these transport vessels. … [1] (b) Plants make their own food. They make large molecules from smaller molecules. (i) The boxes on the left show some large molecules. The boxes on the right show the smaller molecules the large molecules are made from. Draw one straight line from each large molecule to the smaller molecules it is made from. large molecules smaller molecules oil amino acids protein fatty acids and glycerol starch glucose [2] (ii) Oils are stored in the seeds of a plant. A test is used to find the presence of oil in seeds. State the name of this test. … [1] (c) Oil from palm trees has many uses. Fig. 1.3 shows the mass of palm oil used worldwide between 2006 and 2016. 60 55 mass of 50 palm oil used worldwide / × 109 kg 45 40 35 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 year Fig. 1.3 (i) Use Fig. 1.3 to determine the mass of palm oil used worldwide in 2011. … ×109 kg [1] (ii) Areas of rainforest are removed to plant palm trees for oil. Describe how deforestation affects the animals living in the rainforest. … … … [2] [Total: 10]

10 marks

Mark scheme: 1(a)(i) xylem ; mesophyll ; stomata ; 3 1(a)(ii) D ; 1 1(b)(i) oil amino acids protein fatty acids and glycerol starch glucose one correct ; three correct ; 2 1(b)(ii) ethanol (emulsion) ; 1 1(c)(i) 48 (× 109 kg ) ; 1 1(c)(ii) any two from: loss of habitat ; less food OR disruption to food, webs / chains ; less shelter ; migration (of species) ; extinction (of species) ; 2

This question in 0653/32 Oct/Nov 2021

1 (a) A blue dye is dissolved in water to make a blue liquid. Fig. 1.1 shows a cut plant stem in a beaker of the blue liquid. leaves plant stem blue liquid Fig. 1.1 The plant stem is left in the blue liquid for 24 hours. (i) Complete the sentences to explain why the leaves turn blue. Choose words from the list. Each word may be used once, more than once or not at all. cortex mesophyll phloem root hair stomata xylem The blue liquid moves up the plant stem in vessels called … . In the leaves, the blue liquid moves out of the vessels into … cells. Water in the blue liquid then diffuses out of the … into the air. [3] (ii) Fig. 1.2 shows the cross-section of the plant stem from Fig. 1.1. A B C D Fig. 1.2 The blue liquid only stains the transport vessels in the stem blue. Identify the letter in Fig. 1.2 that shows these transport vessels. … [1] (b) Plants make their own food. They make large molecules from smaller molecules. (i) The boxes on the left show some large molecules. The boxes on the right show the smaller molecules the large molecules are made from. Draw one straight line from each large molecule to the smaller molecules it is made from. large molecules smaller molecules oil amino acids protein fatty acids and glycerol starch glucose [2] (ii) Oils are stored in the seeds of a plant. A test is used to find the presence of oil in seeds. State the name of this test. … [1] (c) Oil from palm trees has many uses. Fig. 1.3 shows the mass of palm oil used worldwide between 2006 and 2016. 60 55 mass of 50 palm oil used worldwide / × 109 kg 45 40 35 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 year Fig. 1.3 (i) Use Fig. 1.3 to determine the mass of palm oil used worldwide in 2011. … ×109 kg [1] (ii) Areas of rainforest are removed to plant palm trees for oil. Describe how deforestation affects the animals living in the rainforest. … … … [2] [Total: 10]

10 marks

Mark scheme: 1(a)(i) xylem ; mesophyll ; stomata ; 3 1(a)(ii) D ; 1 1(b)(i) oil amino acids protein fatty acids and glycerol starch glucose one correct ; three correct ; 2 1(b)(ii) ethanol (emulsion) ; 1 1(c)(i) 48 (× 109 kg ) ; 1 1(c)(ii) any two from: loss of habitat ; less food OR disruption to food, webs / chains ; less shelter ; migration (of species) ; extinction (of species) ; 2

This question in 0653/33 Oct/Nov 2021

4 (a) Fig. 4.1 is a diagram of the human heart. (i) Complete the labels on Fig. 4.1. V right … right … … Fig. 4.1 [3] (ii) The arrows on Fig. 4.1 show the direction of blood flow. Use this information to state why vessel V is an artery. … [1] (iii) The heart is part of the transport system in humans. State the name of this transport system. … [1] (b) Arteries and veins transport substances in the human body. State the name of the two transport vessels in plants. 1 … 2 … [2] (c) A student investigates water transport in plants using two leaves from the same plant. Fig. 4.2 shows the apparatus the student uses. spring balance leaf covered with waterproof petroleum jelly leaf not covered with petroleum jelly test-tube of water A B Fig. 4.2 The student uses the spring balance to measure the mass of each leaf at the start. Both leaves are placed in the same conditions. The mass of each leaf is then measured again 24 hours later. Table 4.1 shows the results. Table 4.1 change in mass at start mass at end leaf mass / g / g / g A 31 25 B 32 31 –1 (i) Calculate the change in mass for leaf A. change in mass = … g [1] (ii) Explain the results in Table 4.1. Use ideas about stomata in your answer. … … … … … [3] [Total: 11]

11 marks

Mark scheme: 4(a)(i) atrium ; ventricle ; septum ; 3 4(a)(ii) idea it is taking blood away from the heart ; 1 4(a)(iii) circulatory / circulation ; 1 4(b) phloem ; xylem ; 2 4(c)(i) –6 (g) ; 1 4(c)(ii) any three from: water is lost from stomata ; by transpiration ; in B, stomata are blocked / water cannot get through stomata ; (B) less water loss so less mass loss ; Max 3 marks 3

This question in 0653/33 May/June 2022

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

4 (a) Transpiration is loss of water vapour from plant leaves. (i) Describe the effect of temperature on transpiration. … … [1] (ii) Plants take in more water than is lost from the leaves. State one use of water in plants. … [1] (b) Fig. 4.1 is a photomicrograph of some of the cells in a plant root. Fig. 4.1 (i) Draw a label line and the letter X on Fig. 4.1 to identify a xylem vessel. [1] (ii) Water is transported from the soil to the xylem vessels through two types of cell. State the names of the two types of cell. 1 … 2 … [2] (c) Plants and animals are both sources of food for humans. A balanced diet needs to contain fibre and starch. (i) State the dietary importance of fibre. … … [1] (ii) Circle the food that is a principal source of fibre. chicken eggs milk potatoes [1] (iii) State the name of the smaller molecules that starch is made from. … [1] [Total: 8]

8 marks

Mark scheme: 4(a)(i) as temperature increases, transpiration increases / ORA ; 1 4(a)(ii) photosynthesis / AVP ; 1 4(b)(i) any large vessel in centre labelled ; 1 4(b)(ii) root hair (cells) ; 2 cortex (cells) ; 4(c)(i) helps to move food through the alimentary canal ; 1 4(c)(ii) potatoes ; 1 4(c)(iii) glucose ; 1

This question in 0653/31 Oct/Nov 2023

1 (a) Fig. 1.1 is a diagram of the human gas exchange system. A B C E D Fig. 1.1 (i) State the letter in Fig. 1.1 that identifies: one of the bronchi … the trachea. … [2] (ii) Circle the name of the blood vessel that takes blood from the lungs to the heart. aorta pulmonary artery pulmonary vein vena cava [1] (b) Table 1.1 shows the composition of inspired air and expired air. Table 1.1 percentage in percentage in gas inspired air expired air nitrogen 79 79 oxygen 21 16 gas X 0.04 4 water vapour variable saturated (i) State the name of gas X in Table 1.1. … [1] (ii) Calculate the difference between the percentage of oxygen in inspired and expired air. … % [1] (iii) State the name of one process in the body that uses oxygen. … [1] (c) Gas exchange takes place through stomata in the leaves of a plant. Stomata are also involved in water loss. (i) Complete the sentences to describe how water is lost from the leaves. The water evaporates from the surfaces of the … cells. The water vapour then exits the leaf by … through the stomata. This process of water loss is called … . [3] (ii) Suggest why stomata may close on very hot dry days. … [1] [Total: 10]

10 marks

Mark scheme: Question Answer Marks 1(a)(i) E ; 2 B ; 1(a)(ii) pulmonary vein ; 1 1(b)(i) carbon dioxide ; 1 1(b)(ii) 5 ; 1 1(b)(iii) (aerobic) respiration ; 1 1(c)(i) mesophyll ; 3 diffusion / diffusing ; transpiration ; 1(c)(ii) to reduce water loss ; 1

This question in 0653/32 Oct/Nov 2023

1 (a) Fig. 1.1 is a diagram of the human gas exchange system. A B C E D Fig. 1.1 (i) State the letter in Fig. 1.1 that identifies: one of the bronchi … the trachea. … [2] (ii) Circle the name of the blood vessel that takes blood from the lungs to the heart. aorta pulmonary artery pulmonary vein vena cava [1] (b) Table 1.1 shows the composition of inspired air and expired air. Table 1.1 percentage in percentage in gas inspired air expired air nitrogen 79 79 oxygen 21 16 gas X 0.04 4 water vapour variable saturated (i) State the name of gas X in Table 1.1. … [1] (ii) Calculate the difference between the percentage of oxygen in inspired and expired air. … % [1] (iii) State the name of one process in the body that uses oxygen. … [1] (c) Gas exchange takes place through stomata in the leaves of a plant. Stomata are also involved in water loss. (i) Complete the sentences to describe how water is lost from the leaves. The water evaporates from the surfaces of the … cells. The water vapour then exits the leaf by … through the stomata. This process of water loss is called … . [3] (ii) Suggest why stomata may close on very hot dry days. … [1] [Total: 10]

10 marks

Mark scheme: Question Answer Marks 1(a)(i) E ; 2 B ; 1(a)(ii) pulmonary vein ; 1 1(b)(i) carbon dioxide ; 1 1(b)(ii) 5 ; 1 1(b)(iii) (aerobic) respiration ; 1 1(c)(i) mesophyll ; 3 diffusion / diffusing ; transpiration ; 1(c)(ii) to reduce water loss ; 1

This question in 0653/33 Oct/Nov 2023

4 (a) Blood and blood vessels are part of the circulatory system in humans. (i) State the component of blood involved in phagocytosis. … [1] (ii) State the name of the blood vessel that transports blood from the heart to the lungs. … [1] (iii) Blood transports hormones around the body. Complete the sentences to describe hormones. A hormone is a chemical substance produced by a … . Hormones alter the activity of a specific … organ. [2] (b) The circulatory system transports oxygen from the lungs to the rest of the body. Fig. 4.1 shows the gas exchange system in humans. X Fig. 4.1 (i) Identify the part labelled X shown on Fig. 4.1. … [1] (ii) Draw a label line and the letter D to identify the diaphragm on Fig. 4.1. [1] (c) Water is transported through xylem vessels in plants from the roots to the leaves. (i) Describe how the water vapour is lost from the leaves of plants. … … … [2] (ii) State the effect of an increase in humidity on the rate of water loss from leaves. … [1] [Total: 9]

9 marks

Mark scheme: 4(a)(i) white blood cells ; 1 4(a)(ii) pulmonary artery ; 1 4(a)(iii) gland ; 2 target ; 4(b)(i) trachea ; 1 4(b)(ii) diaphragm labelled ; 1 4(c)(i) diffusion ; 2 through stomata ; 4(c)(ii) decreases ; 1

This question in 0653/32 Feb/March 2024