Cambridge IGCSE Biology (9-1) 0970 — 2025 Oct/Nov Paper 3 · Variant 2

1 (a) Fig. 1.1 shows the skeletons of five organisms. E A D B C P not to scale Fig. 1.1 (i) State the name of the kingdom to which the organisms in Fig. 1.1 belong. ..................................................................................................................................... [1] (ii) The organisms in Fig. 1.1 can be classified into a group because they have a common feature which is visible in the diagram. State the name of this group. ..................................................................................................................................... [1] (iii) State one feature, visible in Fig. 1.1, that identifies organism D as a fish. ..................................................................................................................................... [1] (iv) Organism E is a mammal. State two features that are found in most mammals. 1 ........................................................................................................................................ 2 ........................................................................................................................................ [2] (v) State the name of the structure labelled P in Fig. 1.1. ..................................................................................................................................... [1] (b) The scientific name for organism A in Fig. 1.1 is Phasianus colchicus. (i) State the species name for organism A. ..................................................................................................................................... [1] (ii) Describe what is meant by the term species. ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] [Total: 9]

Mark scheme: Question Answer Marks Guidance 1(a)(i) animal ; 1 1(a)(ii) vertebrates ; 1 1(a)(iii) fin (bones) / gill (plate) ; 1 1(a)(iv) any two from: 2 hair / fur ; mammary glands ; pinnae / external ears ; four–chambered heart ; sweat glands ; different types of teeth ; diaphragm ; AVP ; 1(a)(v) rib ; 1 1(b)(i) Phasianus colchicus / colchicus ; 1 1(b)(ii) group of organisms / same type of organisms ; 2 (reproduce to give) fertile offspring ;

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2 Fig. 2.1 shows red blood cells in three different concentrations of salt solution. salt solution A salt solution B salt solution C Fig. 2.1 (a) (i) Using the information in Fig. 2.1, state the letter of the salt solution that has a concentration similar to blood plasma. Explain your choice. salt solution ........................... explanation ........................................................................................................................ ........................................................................................................................................... ........................................................................................................................................... [2] (ii) Using the information in Fig. 2.1, list the salt solutions, A, B and C, in order of increasing salt concentration. lowest highest ..................................................................................................................................... [1] (b) State the names of two substances, other than blood cells, that are transported in blood plasma. 1 ................................................................................................................................................ 2 ................................................................................................................................................ [2] (c) Plant tissues can be used to investigate osmosis. Describe the appearance of a plant cell after being placed in distilled water for one hour. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (d) Table 2.1 contains statements about the movement of substances. Place ticks () in the rows to indicate if the statement is true for diffusion or osmosis or both. Table 2.1 statement diffusion osmosis happens in all living cells particles move randomly always involves a partially permeable membrane ions move down a concentration gradient [4] (e) State the name of the type of movement of particles that uses energy from respiration. ............................................................................................................................................. [1] [Total: 12]

Mark scheme: 2(a)(i) B ; 2 cell is, normal shape / not swollen / not shrunken ; 2(a)(ii) C B A ; 1 2(b) any two from: 2 ions ; nutrients ; urea ; hormones ; water ; AVP ; e.g. oxygen / carbon dioxide 2(c) any two from: 2 swollen / larger / more rounded / AW ; no gap between the cell membrane and the cell wall / AW ; idea of full vacuole; 2(d) 4 one mark per correct row statement diffusion osmosis happens in all living cells ✓ ✓ ; particles move randomly ✓ ✓ ; always involves a partially ; ✓ permeable membrane ions move down a concentration ; ✓ gradient 2(e) active transport ; 1

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3 (a) Fig. 3.1 shows part of a tree that is infected with a pathogen. uninfected leaf infected leaf Fig. 3.1 (i) Suggest two processes that cannot occur in the infected leaf that can occur in the uninfected leaf in Fig. 3.1. 1 ........................................................................................................................................ ........................................................................................................................................... 2 ........................................................................................................................................ ........................................................................................................................................... [2] (ii) State the names of two types of pathogen. 1 ........................................................................................................................................ 2 ........................................................................................................................................ [2] (iii) Suggest two ways that pathogens are transmitted between trees. 1 ........................................................................................................................................ ........................................................................................................................................... 2 ........................................................................................................................................ ........................................................................................................................................... [2] (b) Pathogens are one cause of deforestation. Describe other causes of deforestation. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (c) Fig. 3.2 shows the area of rainforest that was removed between 2004 and 2022 in one country. 30 25 area of rainforest 20 removed in one country 15/ thousand km2 10 5 2004 2007 2010 2013 2016 2019 2022 year Fig. 3.2 Describe the data shown in Fig. 3.2. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (d) One undesirable effect of deforestation is a reduction in biodiversity. (i) Describe what is meant by the term biodiversity. ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) Describe undesirable effects of deforestation, other than reducing biodiversity. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [3] [Total: 17]

Mark scheme: 3(a)(i) any two from: 2 photosynthesis ; gas exchange ; transpiration ; transport ; storage of starch ; respiration ; growth ; chlorophyll production ; 3(a)(ii) (named) bacteria ; 2 (named) viruses ; AVP ; e.g. fungi 3(a)(iii) any two from: 2 direct (transfer) OR trees / branches / leaves / roots, touch ; (indirect transfer by) animals / insects / any named organism ; air / wind ; water / soil ; pollination ; AVP ; e.g. (contaminated) tools 3(b) any three from: 3 (cleared land) used for building , housing / urban development / factories / infrastructure / roads / railways / AW; (cleared land) used for, growing crops / farming / livestock production / AW ; (cleared land) used for, extraction of natural resources / mining / quarrying ; harvesting / (named) use of, timber / wood ; climate change / global warming ; AVP ; e.g. volcanic eruption / defoliation by insects / pollution 3(c) any three from: 3 area removed decreases and then increases ; (overall) decrease, greater / faster, than the increase ora ; the greatest area was removed in 2004 ; the smallest area was removed in 2013 ; data quote ; AVP ; 3(d)(i) number of (different) species ; 2 in an area ; 3(d)(ii) any three from: 3 habitat, destruction / loss / reduction ; less food available / disruption of food chains ; loss / destruction, of soil ; flooding ; increased carbon dioxide in the atmosphere ; global warming / climate change / enhanced greenhouse effect ; AVP ;

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4 (a) Fig. 4.1 is a diagram of the female reproductive system. H D G E F Fig. 4.1 (i) State the letter in Fig. 4.1 that identifies: the vagina .............................................. an oviduct .............................................. an egg cell. .............................................. [3] (ii) Draw a label line and the letter X on Fig. 4.1 to show where fertilisation normally occurs. [1] (iii) State the name of the organ shown in Fig. 4.1 that produces a female reproductive hormone and state one function of the hormone. organ ................................................................................................................................. function .............................................................................................................................. ........................................................................................................................................... ........................................................................................................................................... [2] (b) Complete the sentences about the endocrine system using words from the list. Each word may be used once, more than once or not at all. digestion external glands glucose homeostasis insulin internal muscles neurones phagocytosis testosterone tissues The endocrine system contains organs called .......................................... . These organs produce hormones. Some hormones help to maintain a constant .......................................... environment. This is called .......................................... . The pancreas produces a hormone called .......................................... that helps to control blood .......................................... concentration. [5] [Total: 11]

Mark scheme: 4(a)(i) vagina F ; 3 oviduct D ; egg cell E ; 4(a)(ii) X drawn with a label line ending in or on an oviduct ; 1 4(a)(iii) organ ovary ; 2 I and one from: development of, secondary sexual characteristics / named characteristic ; AVP ; 4(b) glands ; 5 internal ; homeostasis ; insulin ; glucose ;

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5 Pea plants produce seeds in pods. The colour of pea pods is controlled by a single gene. Some pea pods are green and some are yellow. The allele for green is dominant and is represented by the letter G. The allele for yellow is recessive and is represented by the letter g. (a) Describe what is meant by the term allele. ................................................................................................................................................... ............................................................................................................................................. [2] (b) Fig. 5.1 is a pedigree diagram for the inheritance of pod colour in some pea plants. Key green pod yellow pod 1 2 3 4 5 6 7 Fig. 5.1 The possible genotypes for pea pod colour are GG, Gg and gg. Determine the genotypes of individual 1 and individual 2 in Fig. 5.1. Explain how you determined your answer for each individual. individual 1 genotype ........................... explanation ............................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... individual 2 genotype ........................... explanation ............................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... [4] (c) Two pea plants with the genotype Gg for pod colour are bred together. Complete the Punnett square to determine the possible genotypes of the offspring and calculate the expected phenotypic ratio. ................................... ................................... ................................... ................................... ................................... ................................... ................................... ................................... The expected phenotypic ratio of the offspring is .................. green pods : .................. yellow pods. [3] [Total: 9]

Mark scheme: 5(a) alternative form / different versions ; 2 of a gene ; 5(b) individual 1: gg / homozygous recessive ; 4 it is yellow / it is not green ; A if G was present, it would be green individual 2: Gg / heterozygous ; there are yellow offspring ; A individuals 4 and 6 could not be produced (if GG) / both pod colours can only be produced if Gg 5(c) both parental gametes are G and g ; 3 ecf for incorrect previous step offspring are GG Gg Gg gg ; 3 (green pod :) 1 (yellow pod) ;

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6 (a) Fig. 6.1 is a diagram of a spongy mesophyll cell. J K chloroplast L Fig. 6.1 (i) State the name of the organ that contains spongy mesophyll cells. ..................................................................................................................................... [1] (ii) State the names of structures J, K and L in Fig. 6.1. J ........................................................................................................................................ K ........................................................................................................................................ L ........................................................................................................................................ [3] (iii) Describe one function of the nucleus. ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [1] (iv) Draw an M on Fig. 6.1 to show where mitochondria are found. [1] (v) State the function of mitochondria. ........................................................................................................................................... ..................................................................................................................................... [1] (b) Explain how the spongy mesophyll tissue is adapted for photosynthesis. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] [Total: 10]

Mark scheme: 6(a)(i) leaf / leaves ; 1 6(a)(ii) J cell wall ; 3 K vacuole ; L cytoplasm ; 6(a)(iii) any one from: 1 contain the, genetic material / DNA / chromosomes / genes / alleles ; idea of controls (activities of) the cell ; 6(a)(iv) M drawn in cytoplasm ; 1 6(a)(v) (site of aerobic) respiration / release of energy ; 1 6(b) any three from: 3 contains, chloroplasts / chlorophyll, which absorbs light (energy) / AW ; cells have an irregular shape ; large(r)surface area ; (spongy mesophyll) tissue / cells, loosely packed ; creates (air) spaces ; ref. to diffusion of carbon dioxide ; ref. to gas exchange ; ref. to vascular bundles ;

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7 (a) The boxes on the left show the types of digestion. The boxes on the right contain sentence endings. Draw lines to make four correct sentences. type of digestion sentence ending breaks down food into smaller pieces. Chemical digestion breaks down food molecules. involves chemical changes. Physical digestion involves enzymes. [4] (b) Ingestion occurs in the mouth. State the name of the part of the alimentary canal where egestion occurs. ............................................................................................................................................. [1] (c) Fig. 7.1 shows a section through a human tooth. Q R S F Fig. 7.1 (i) State the names of structures Q, R and S in Fig. 7.1. Q ....................................................................................................................................... R ........................................................................................................................................ S ........................................................................................................................................ [3] (ii) State the names of two structures found inside the pulp. 1 ........................................................................................................................................ 2 ........................................................................................................................................ [2] (iii) Identify the type of tooth shown in Fig. 7.1. Explain how you made your choice. type ................................................................................................................................... explanation ........................................................................................................................ ........................................................................................................................................... ........................................................................................................................................... [2] [Total: 12]

Mark scheme: 7(a) 4 R each additional line breaks down food into smaller pieces. Chemical digestion breaks down food molecules. involves chemical changes. Physical digestion involves enzymes. 7(b) anus ; 1 7(c)(i) Q enamel ; 3 R dentine ; S gum ; 7(c)(ii) nerves / neurones / nerve cell / receptors ; 2 blood vessels ; 7(c)(iii) molar ; 2 any one from: flat top / grinding surface / large surface ; multiple roots ;

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