Cambridge A Level Biology 9700 — 2025 Oct/Nov Paper 1 · Variant 4

This document has 20 pages. Any blank pages are indicated. IB25 11_9700_14/6RP © UCLES 2025 [Turn over *4564272684* Cambridge International AS & A Level BIOLOGY 9700/14 Paper 1 Multiple Choice October/November 2025 1 hour 15 minutes You must answer on the multiple choice answer sheet. You will need: Multiple choice answer sheet Soft clean eraser Soft pencil (type B or HB is recommended) INSTRUCTIONS  There are forty questions on this paper. Answer all questions.  For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the multiple choice answer sheet.  Follow the instructions on the multiple choice answer sheet.  Write in soft pencil.  Write your name, centre number and candidate number on the multiple choice answer sheet in the spaces provided unless this has been done for you.  Do not use correction fluid.  Do not write on any bar codes.  You may use a calculator. INFORMATION  The total mark for this paper is 40.  Each correct answer will score one mark.  Any rough working should be done on this question paper.

2 © UCLES 2025 9700/14/O/N/25 1 Which structures are visible in an appropriately stained plant cell using a high power (400) light microscope? centrioles mitochondria starch grains A    key B     = visible C     = not visible D    2 The images show an eyepiece graticule and a stage micrometer scale viewed through a microscope. The smallest divisions of the stage micrometer scale are 0.01 mm. The images also show a photomicrograph of a transverse section through a plant root using the same eyepiece graticule and the same magnification. 0 10 20 30 40 50 0.0 0.1 0.2 0.3 eyepiece graticule stage micrometer scale 0 10 20 30 40 50 X Y What is the actual width of the vascular tissue in the plant root between X and Y? A 17 m B 25 m C 170 m D 250 m

3 © UCLES 2025 9700/14/O/N/25 [Turn over 3 It is thought that some organelles in eukaryotic cells evolved from free-living prokaryotes. Which organelles have features that suggest they evolved from free-living prokaryotic ancestors? A chloroplasts and mitochondria B chloroplasts and Golgi bodies C mitochondria and smooth endoplasmic reticulum D Golgi bodies and smooth endoplasmic reticulum 4 A student completed a table showing the structures that are found in four different types of cells. cell structure cell Q cell R cell S cell T cell surface membrane     cellulose cell wall     key chloroplast      = present mitochondrion      = not present nucleus     How many of these types of cells can be found in plants? A 1 B 2 C 3 D 4 5 Some features of cells are listed. 1 cytoplasm 2 cell surface membrane 3 ribosomes Which features are found in animal cells and also in prokaryotic cells? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

4 © UCLES 2025 9700/14/O/N/25 6 Trehalose is a non-reducing disaccharide. Separate samples of a mixture of fructose and trehalose were tested with Benedict’s solution before and after acid hydrolysis. What will be the results of these Benedict’s tests? before acid hydrolysis after acid hydrolysis A   key B    = positive result with Benedict’s test C    = negative result with Benedict’s test D   7 Which molecules have a structural formula that contains C=O bonds? 1 glucose 2 glycerol 3 protein A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 8 Which statement about monosaccharides and disaccharides is correct? A Sucrose is a non-reducing disaccharide produced from two identical monosaccharides joined together by a condensation reaction. B The hydrolysis of the reducing disaccharide maltose produces a reducing monosaccharide, and a non-reducing monosaccharide. C Maltose is a non-reducing disaccharide that contains two identical reducing monosaccharides connected by a glycosidic bond. D The addition of a water molecule to the glycosidic bond in a sucrose disaccharide produces two different reducing monosaccharides.

5 © UCLES 2025 9700/14/O/N/25 [Turn over 9 Which row is correct for glycogen? glycogen is hydrolysed rapidly due to its branched structure glycogen is insoluble so the water potential of cells is unaffected glycogen is a compact molecule because it contains many -glucose molecules A    B    C    D    key  = correct for glycogen  = incorrect for glycogen 10 The diagram shows a section of a polysaccharide. O O H H H H CH2OH OH H OH O C C C C C H H H CH2OH H H OH OH O C C C C C O O O H H H H CH2OH OH H OH O C C C C C H H H CH2OH H H OH OH O C C C C C Which statement about this polysaccharide is correct? A It coils into a tight helix that provides a compact shape for energy storage in cells. B It has high tensile strength when arranged into fibrils in plant cell walls. C It folds into a globular shape that is soluble in water and easily transported. D It combines with protein molecules to act as cell markers on the cell surface membrane.

6 © UCLES 2025 9700/14/O/N/25 11 Thermostable enzymes can maintain their tertiary structure at high temperatures. Scientists studying the primary structure of a thermostable enzyme found that the enzyme contained: ● more charged amino acids ● fewer polar amino acids that are not charged ● more hydrophobic amino acids than enzymes that are not thermostable. Which row shows a correct comparison between this thermostable enzyme and an enzyme that is not thermostable? number of amino acids forming interactions at the centre of a thermostable enzyme compared to an enzyme that is not thermostable number of ionic bonds in a thermostable enzyme compared to the number in an enzyme that is not thermostable A less than more than B less than less than C more than less than D more than more than 12 Collagen is a strong, elastic molecule that is often found in the connective tissues of animals. Glycine is an amino acid found at regular positions in the primary structure of a collagen polypeptide. Which row shows features of collagen that contribute to its strength and elasticity? glycine is found on the outside of the helical polypeptides to allow them to lie closer together disulfide bonds form between glycine amino acids to join the polypeptides together A   B   C   D   key  = contributes to the strength and elasticity of collagen  = does not contribute to the strength and elasticity of collagen

7 © UCLES 2025 9700/14/O/N/25 [Turn over 13 Which statements describe the action of an extracellular enzyme? 1 synthesis of a polynucleotide in the nucleus during DNA replication 2 digestion of macromolecules in the lumen of the small intestine 3 synthesis of ATP molecules in the mitochondria A 1 and 2 B 1 and 3 C 2 and 3 D 2 only 14 Which statement about the induced-fit hypothesis of enzyme action is correct? A An enzyme that uses the induced-fit mechanism will increase the activation energy of a reaction. B The binding of a substrate causes conformational changes in an enzyme. C The active site of an enzyme changes to become the same shape as the substrate. D An enzyme that uses an induced-fit mechanism has decreased specificity to the substrate. 15 Graph J shows the effect of pH on the rate of an enzyme reaction. Graph K shows the effect of substrate concentration on the rate of an enzyme reaction. rate of reaction rate of reaction pH substrate concentration graph J graph K P Q R 0 0 0 0 A student wrote four statements about the graphs. 1 In graph J, the enzyme is denatured at point Q. 2 In graph J, the enzyme is inactive at point P. 3 In graph K, the rate of reaction is directly proportional to the substrate concentration. 4 In graph K, Vmax is reached at point R. Which statements are correct? A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

8 © UCLES 2025 9700/14/O/N/25 16 The diagram shows a section through a cell surface membrane. P Q R S What is a correct role for a labelled molecule? A P is involved in controlling membrane stability. B Q is involved in active transport. C R is involved in cell signalling. D S is involved in diffusion of ions. 17 When red blood cells are put into distilled water they burst (haemolysis). Which statements explain this haemolysis? 1 The water potential of the surrounding liquid is lower than the water potential of the contents of the red blood cell. 2 The cell surface membranes of red blood cells are not supported by cell walls. 3 More water moves into the red blood cells by osmosis than leaves the cells. 4 Water enters the red blood cells by osmosis but does not leave the cells. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

9 © UCLES 2025 9700/14/O/N/25 [Turn over 18 The diagrams show the shape and size of two types of cell. 10 μm 10 μm 50 μm 10 μm 5 μm 45 μm palisade mesophyll cell surface area = 2200 μm2 columnar epithelial cell volume = 2250 μm3 not to scale Which statement about the palisade cell and epithelial cell shown in the diagrams is correct? A An increase in surface area reduces the distance for gases to reach the centre of the cell. B The surface area of the palisade mesophyll cell is 500 m2 greater than the columnar epithelial cell. C The surface area to volume ratio is greater in the columnar epithelial cell than the palisade mesophyll cell. D The volume of the palisade mesophyll cell is 2500 m3 greater than that of the columnar epithelial cell.

10 © UCLES 2025 9700/14/O/N/25 19 The DNA content of a cell changes as the mitotic cell cycle proceeds through a series of stages. time DNA content per cell 1 2 3 4 1 Which row correctly identifies when DNA replicates and when the nuclear envelope breaks down? DNA replicates nuclear envelope breaks down A 1 3 B 1 4 C 2 3 D 2 4 20 The diagram shows three cycles of cell division from an original cell of cell type P in bone marrow. Some of the cells that form are cell type Q. not to scale key cell type P cell type Q Which row correctly identifies cell type P and cell type Q? cell type P cell type Q A cancer cell differentiated cell B cancer cell stem cell C differentiated cell stem cell D stem cell differentiated cell

11 © UCLES 2025 9700/14/O/N/25 [Turn over 21 A student made a drawing of two chromosomes at stage K of a mitotic cell cycle. no chromosomes were visible stage J stage K stage M stage L Which row shows the possible events that occur in stages J, L and M? J L M A spindle attachment cytokinesis DNA replication B chromosome condensation spindle attachment cytokinesis C DNA replication chromosome condensation spindle attachment D cytokinesis DNA replication chromosome condensation

12 © UCLES 2025 9700/14/O/N/25 22 During DNA replication, the two original strands of a DNA molecule separate. Which diagram shows the direction in which DNA polymerase moves along each of the original strands during DNA replication? A B C D O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 5′ 5′ 3′ 3′ 5′ 5′ 3′ 3′ 5′ 5′ 3′ 3′ 5′ 5′ 3′ 3′

13 © UCLES 2025 9700/14/O/N/25 [Turn over 23 Which statements about anticodons are correct? 1 The base sequence of an anticodon will always be the same as that of the corresponding triplet on the transcribed DNA strand. 2 There are 20 naturally occurring amino acids, so therefore there are only 20 anticodons as each anticodon is specific for only one amino acid. 3 The formation of hydrogen bonds between the bases of the anticodon with those of the complementary mRNA codon must occur before the new peptide bond can form. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 3 only 24 Part of a DNA molecule is transcribed to form an RNA molecule that is then modified. Which row describes the RNA molecule before and after modification? before modification after modification A contains exons and introns contains exons only B contains exons and introns contains introns only C contains exons only contains introns only D contains introns only contains exons only 25 When a gene mutation occurs, which of the following may be altered, resulting in the production of a non-functional protein? 1 amino acid sequence 2 DNA nucleotide sequence 3 mRNA nucleotide sequence A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 2 only

14 © UCLES 2025 9700/14/O/N/25 26 The diagrams show the arrangements of phloem and xylem tissues in some plant organs. R Q epidermis phloem xylem epidermis phloem xylem T S epidermis phloem xylem epidermis phloem xylem Where will arrangements Q, R, S and T be found in plants? Q R S T A leaf root stem root B root stem root leaf C stem stem leaf root D stem root leaf stem 27 Which feature of xylem vessel elements allows them to have reduced resistance to water movement? A Lignin forms an incomplete secondary wall. B New vessels transport extra water as a plant grows. C There are no cross walls between vessel elements. D Vessel elements join to form narrow tubes. 28 Which statement describes movement through a plant in the apoplast pathway? A Water moves through the cell walls. B Water moves through the cytoplasm. C Water moves through the plasmodesmata. D Water moves through the vacuoles.

15 © UCLES 2025 9700/14/O/N/25 [Turn over 29 What is the correct name for the attraction due to the hydrogen bonding between water molecules during mass flow in plants? A transpiration B cohesion C tension D adhesion 30 Which row shows the cause of mass flow in the phloem and the direction of movement of phloem sap by mass flow? cause of mass flow in the phloem direction of movement of phloem sap by mass flow A hydrostatic pressure gradient sink to source B hydrostatic pressure gradient source to sink C water potential gradient sink to source D water potential gradient source to sink 31 The graph shows the thickness of the walls of the main blood vessels to and from a mammalian heart. Which blood vessel is the pulmonary artery? 1.2 1.0 0.8 0.6 0.4 0.2 0 A B C D blood vessel thickness of blood vessel wall / mm

16 © UCLES 2025 9700/14/O/N/25 32 The photomicrographs show blood smears from two different people. Person J does not have a disorder that affects their blood. Person K does have a disorder that affects their blood. person J person K The table shows some disorders that increase or decrease the number of neutrophils, red blood cells or lymphocytes. disorders related to blood count changes increase decrease neutrophil chronic inflammation autoimmune neutropenia red blood cell heart failure anaemia lymphocyte chronic leukaemia sepsis Which disorder does person K have? A autoimmune neutropenia B heart failure C sepsis D chronic leukaemia 33 Which statement correctly describes the Bohr shift? A the decrease in affinity of haemoglobin for oxygen that occurs when pH is lowered B the increase in affinity of haemoglobin for oxygen that occurs when oxygen concentration rises C the increase in affinity of haemoglobin for oxygen that occurs when pH is at an optimum D the release of oxygen from oxyhaemoglobin in the absence of carbonic acid

17 © UCLES 2025 9700/14/O/N/25 [Turn over 34 Which row correctly describes the features for two of the heart chambers? left atrium left ventricle A large force of contraction to allow blood to travel a long distance large force of contraction to allow blood to travel a long distance B small force of contraction as blood only needs to travel a short distance large force of contraction to allow blood to travel a long distance C small force of contraction as blood only needs to travel a short distance small force of contraction as blood only needs to travel a short distance D large force of contraction to allow blood to travel a long distance small force of contraction as blood only needs to travel a short distance 35 The photomicrograph shows a transverse section of part of the human gas exchange system. Which row shows the correct name and function of one of the labelled structures in the photomicrograph? A B C D name function A ciliated epithelial cell traps particles B goblet cell secretes mucus C cartilage prevents collapse of trachea D smooth muscle contracts to expand airways

18 © UCLES 2025 9700/14/O/N/25 36 Infectious diseases may be caused by bacteria, protoctists and viruses. Different pathogens may be transmitted by airborne droplets, from faeces to mouth (faecal-oral), by sexual intercourse and by vectors. Four examples of infectious diseases are listed. 1 cholera 2 HIV/AIDS 3 malaria 4 tuberculosis Which table classifies the four diseases correctly to show the type of pathogen that causes the disease and the mode of transmission? droplet faecal-oral sexual vector bacterium 1 protoctist 3 virus 2 4 A droplet faecal-oral sexual vector bacterium 1 protoctist 3 virus 2 4 B droplet faecal-oral sexual vector bacterium 1 protoctist 2 virus 4 3 C droplet faecal-oral sexual vector bacterium 2 protoctist 1 virus 3 4 D

19 © UCLES 2025 9700/14/O/N/25 37 Scientists investigated the sensitivity and resistance of a bacterium called Clostridium difficile to four antibiotics. Colonies of bacteria were grown on agar plates for 24 hours, after which a different antibiotic was added to each plate. The number of bacterial colonies that died, stopped growing and continued growing were then counted. A bacterial colony is a group of bacterial cells that have multiplied from one bacterium. Which antibiotic would be the best to treat a person infected with Clostridium difficile? antibiotic number of colonies that died number of colonies that stopped growing number of colonies that continued growing A ampicillin 2 5 13 B clindamycin 4 8 6 C metronidazole 13 6 1 D cefoxitin 9 5 4 38 A vaccine is used to create artificial active immunity. After a person has been given a vaccine, it takes a period of time before they develop long-term immunity to the disease. Which statement about this period of time explains the delay in developing long-term immunity? A No memory cells have been produced from B-lymphocytes. B No plasma cells have been produced from B-lymphocytes. C The primary immune response has not produced enough antibodies. D The secondary immune response has not produced enough antibodies. 39 An antiserum to a snake toxin can be obtained by injecting the toxin into a horse. The antiserum is made from blood plasma taken from the horse a few weeks later. The antiserum is injected into a person who has been bitten by the same species of snake. Which type of immunity occurs as a result of using this antiserum? A artificial active B artificial passive C natural active D natural passive 40 Which statement describes the feature of monoclonal antibodies that allows them to accurately treat a specific disease? A They bind to human hormones to produce a colour change. B A fluorescent dye can be attached to them. C They have active sites that are complementary to antigens. D They can carry toxic chemicals.

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This document consists of 3 printed pages. © Cambridge University Press & Assessment 2025 [Turn over Cambridge International AS & A Level BIOLOGY 9700/14 Paper 1 Multiple Choice October/November 2025 MARK SCHEME Maximum Mark: 40 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the October/November 2025 series for most Cambridge IGCSE, Cambridge International A and AS Level components, and some Cambridge O Level components.

9700/14 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 2 of 3 Question Answer Marks 1 D 1 2 C 1 3 A 1 4 C 1 5 A 1 6 A 1 7 C 1 8 D 1 9 B 1 10 B 1 11 D 1 12 D 1 13 D 1 14 B 1 15 B 1 16 C 1 17 C 1 18 C 1 19 C 1 20 D 1 21 A 1 22 D 1 23 D 1 24 A 1 25 A 1 26 D 1 27 C 1 28 A 1

9700/14 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2025 © Cambridge University Press & Assessment 2025 Page 3 of 3 Question Answer Marks 29 B 1 30 B 1 31 B 1 32 D 1 33 A 1 34 B 1 35 B 1 36 C 1 37 C 1 38 A 1 39 B 1 40 D 1