Br SUPERVISOR TO ATTACH PROCESSING LABEL HERE Write your student number in the boxes above. Letter Biology Question and Answer Book VCE (NHT) Examination — Tuesday 20 May 2025 + Reading time is 15 minutes: 10.30am to 10.45am + Writing time is 2 hours 30 minutes: 10.45 am to 1.15pm Materials supplied + Question and Answer Book of 44 pages + Multiple-Choice Answer Sheet Instructions + Follow the instructions on your Multiple-Choice Answer Sheet. + Atthe end of the examination, place your Multiple-Choice Answer Sheet inside the front cover of this book. Students are not permitted to bring mobile phones and/or any unauthorised electronic devices into the examination room. Contents pages Section A (40 questions, 40 marks), 2-25 Section B (9 questions, 80 marks) 841 Vc cuRRicuLuM rORIA © VCAA2025 AND ASSESSMENT AUTHORITY EtnaPage 2 of 44 Section A 2025 VCE (NHT) Biology Section A — Multiple-choice questions Instructions + Answer all questions in pencil on your Multiple-Choice Answer Sheet + Choose the response that is correct or that best answers the question + Acorrect answer scores 1; an incorrect answer scores 0. + Marks will not be deducted for incorrect answers. + No marks will be given if more than one answer is completed for any question. + Unless otherwise indicated, the diagrams in this book are not drawn to scale. Use the following information to answer Questions 1 and 2. Yeast is used to help make bread. When yeast cells respire anaerobically, they produce a gas that helps make bread rise. Tha Dah Say and Amal wanted to test how the different amounts of yeast used in dough impact the height of a loaf of bread. Each carried out their own experiment. They each used the same bread maker to bake loaves of bread with varying amounts of yeast. They then measured the height of each loaf of bread. All other variables were kept the same. All the baking was completed over the course of one day. The following table shows the height of each loaf of bread. Amount of yeast Bread height {teaspoon) (cm) Tha Dah Say Amal 05 13.8 42 Trial 1.0 159 75 05 13.6 39 Trial 2 1.0 187 74 05 13.7 44 Trial 3 10 16.1 74 Question 1 Which one of the following statements is correct? ‘A. The amount of yeast is the dependent variable as itis a form of quantitative data, B. The height of the bread is the independent variable as Tha Dah Say and Amal chose to measure it in centimetres. C. The amount of yeast is the controlled variable as Tha Dah Say and Amal accurately measured the amount used. D. The height of the bread is the dependent variable because it changes due to the different amounts of yeast present. J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 3 0f44 Question 2 When 0.5 teaspoon of yeast was used, the bread height was consistently lower than when 1.0 teaspoon of yeast was used. This shows that A. the data is quantitative, as a smaller amount of yeast would use a smaller amount of oxygen. B. the trend is reproducible, as Tha Dah Say and Amal's data both showed this correlation. C. the data is qualitative, as each trial indicates that a smaller amount of yeast would produce a smaller amount of gas D. the data is not repeatable, as Amal's data shows a lower bread height in all data sets.Page 4 of 44 Section A 2025 VCE (NHT) Biology Question 3 ‘The diagram below shows the structure of a Hepatitis C virus. The virus is a single-stranded RNA virus. Molecule Source: Aaped fom

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Key <++++ solution with 2s sol enzyme A — — solution with 20-4 enzyme B amount of . — solution with product 154 no enzyme (arbitrary units) time (minutes) Which conclusion can be drawn from this data? A. Enzymes Aand B act as catalysts in this reaction B. Enzyme B is denatured between 15 to 20 minutes, . The reaction only occurs in the presence of an enzyme D. The active site of enzyme Ais less complementary to the substrate than that of enzyme B. FA Ss 5 2 Ps eS o EB 2 A r}Page 8 of 44 Section A 2025 VCE (NHT) Biology Use the following information to answer Questions 7 and 8. Type 1 diabetes mellitus (TDM) can be caused by genetic mutations. DNA profiling was carried out, using gel electrophoresis, to identify if children carry the specific genetic mutation for T1DM. Children without T1DM have fragments all of the same length that run furthest from the well. Any other combinations of fragments result in children being diagnosed with T1DM. Each of lanes 1 to 6 represents a different child tested for the genetic mutation. Lane Mis the DNA base pair (bp) ladder. The results are shown below. 6 5 4 bp 3000 1500 1000 500 400 300 200 100 Source: © Makhzoom, Y Kabalan and FAl-Quoball, ‘Association of KCNJT1 95218 gene polymorphism with type 2 dabetes melts in a population of Syria: a case-conral study, BMC Medical Genetics, 20,2019, Question 7 Referring to the gel run, all the children carrying the specific genetic mutation for T1DM are shown in lanes A. tand4, B. 2and5. C. 1,2,4and5. D. 2,3,5and6. Question 8 To prepare the DNA for profiling T1DM using gel electrophoresis, it is most likely that the scientist would have used both ‘A. polymerase chain reaction and ligase. B. CRISPR-Cas9 and plasmids. ©. endonuclease and polymerase chain reaction. D. insulin and DNA polymerase. J co 5 g 3 s 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 9 0f44 Question 9 Acetyl-CoA binds with the enzyme citrate synthase in the Krebs cycle. A competitive enzyme inhibitor that has the same shape as acetyl-CoA will A. increase the rate of the Krebs cycle by binding to the active site of acetyl-CoA. B, decrease the rate of the Krebs cycle by reducing the number of times acetyl-CoA binds to the active site of citrate synthase in a given time. C. have no effect on the rate of the Krebs cycle because it binds to a site other than the active site of citrate synthase. D. bind to an allosteric site on citrate synthase, decreasing the rate of the Krebs cycle to zero. Question 10 In cellular respiration, the net ATP yield from a single glucose molecule is affected by various factors, Which one of the following factors immediately influences the yield of ATP molecules produced during the electron transport chain? A. the availabilty of glucose in the cristae B. the number of oxygen molecules available in the mitochondria ©. the concentration of pyruvate in the mitochondrial matrix D. the rate of glycolysis in the cytosol Question 11 What could explain the differences in the ATP yield between aerobic and anaerobic respiration in a human cell? ‘A. The electron transport chain is not used in anaerobic respiration, leading to lower ATP production. B. Anaerobic respiration produces more NADH compared to aerobic respiration, which decreases ATP yield. C. The Krebs cycle is more efficient in anaerobic respiration, resulting in higher ATP yield D. Aerobic respiration produces fewer ATP molecules due to the incomplete breakdown of glucose, Question 12 ‘decrease in the rate of glycolysis within a healthy muscle cell is most likely caused by an increase in the A. concentration of glucose. B. number of NAD* molecules. C. concentration of oxygen D. number of ATP molecules.Page 10 of 44 Section A 2025 VCE (NHT) Biology Use the following information to answer Questions 13 and 14. The two reactions shown below are both part of a biochemical pathway occurring in the same stage of photosynthesis in a plant cell Inputs Outputs Reaction 1 water hydrogen ions and oxygen gas Reaction 2 | hydrogen ions NADPH Question 13, ‘Where in the cell would the two reactions shown be occurring? A. inner mitochondrial membrane B. grana C. cytosol D. stroma Question 14 Allimiting factor for this stage of photosynthesis could be A. light intensity. B. glucose concentration . carbon dioxide concentration. D. the amount of ATP molecules. Question 15 One of the roles of water in photosynthesis is to A. act as a catalyst in the light-independent reactions. B. provide electrons for reactions. C. convert directly into glucose. D. actas a carbon source. Question 16 In photosynthesis, which one of the following correctly describes the relationship between the light- dependent and the light-independent reactions? A. The light-dependent reactions produce ATP, which is used in the light independent reactions to help fix carbon into organic molecules. B. The light-ndependent reactions produce ATP from carbon dioxide and water, which is used in the light-dependent reactions. €. The light-dependent reactions use ATP to produce glucose, while the light-independent reactions produce ATP from glucose. D. The light-independent reactions convert ATP into carbon dioxide and water, which are then used in the light-dependent reactions to form glucose, J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 11 of 44 Question 17 Immunoglobulin E (IgE) antibodies are involved in allergic responses. Before an allergic response occurs A. the histamines found in peanuts and dust bind to the active site of IgE antibodies, B. IgE antibodies pass through a physical barrier to bind to mast cells at the variable region. C. plasma B cells produce IgE antibodies, which then bind to receptors on the plasma membrane of mast cells. D. histamines form a chemical barrier when they bind to IgE antibodies, helping to prevent entry of allergens. Question 18 Hay fever is a common allergic response that can occur when people breathe in pollen from grasses and other plants. The symptoms may include sore eyes and a runny nose. Considering hay fever only, which of the following correctly identifies immune responses in hay fever? Blood vessels dilate in| Complement proteins Macrophages response to histamine | directly kill pathogens | phagocytise the pollen A true true false B. true false true c. false true false D. false false true Question 19 Lymph nodes are important organs of the lymphatic system, During an immune response, the lymph nodes A. produce plasma cells that release antigens, B. attract bacteria that are engulfed by antibodies. C. are the site of clonal selection and expansion of B cells. D. release allergens to cause localised swelling in the lymph node.Page 12 of 44 Section A 2025 VCE (NHT) Biology Question 20 The concentration of antibodies for a particular antigen in a person can be measured. Which of the following graphs would be consistent with the antibody concentration in a person who is developing active immunity to the same antigen they are first exposed to on day 0 and then again on day 407 A. 120 100 TT antibody 80 concentration L (arbitrary 7 units) 40 20 0 0 10 20 30 40 50 60 70 120 100) at antibody 80 concentration 69 {arbitrary unis) 40 20) 0, ° 20 30 40 50 60 70 time (days) 120 100 antibody 80 concentration gg (arbitrary units) 49 20 120, 100| antibody 80 concentration go| {arbitrary units) 40 20 0, 0 40 20 30 40 50 60 70 time (days) J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 13 of 44 Question 21 The disease Middle East Respiratory Syndrome (MERS) is caused by a viral pathogen. It is thought that bats were the initial hosts and that the disease spread to camels and then to people. Person-to-person transmission can occur. The steps in transmission are shown below. milkand meat coughing, sneezing, saliva consumption close contact, . y transmission transmission transmission bat camel human human (primary host) _ (intermediate host) ‘Adapted trom: D Chandran, S Chakraborty, O Chandran ata, Middle East Respiratory Syndrome Coronavitus Cule bea Prony Pathogen to Cause Public Health Emergency: Novceable Features and Counteaetve Measures, Environmental Heath sights, 18, 2024 40.1779 78890224127 1545 No specific antiviral medicines exist for the pathogen and currently there is no vaccine. The most effective strategy to prevent the transmission of the disease from non-human to human populations would be A. the development of specific antiviral medications for MERS. B. allowing people to visit zoos that kept both bats and camels, ©. the removal of bats from the forests adjacent to human populations. D. heat-treating milk and fully cooking camel meat before human consumption Question 22 There has been a recent resurgence of measles cases in Europe. Measles is a highly infectious virus transmitted via respiratory droplets and close contact. An effective vaccine has been available since 1963, and until the 1990s scientists thought that the disease could be eliminated. The reasons given were that previous infection or vaccination can produce lifelong immunity, and there is no animal carrier of the human measles virus. The recent outbreaks of measles could be attributed to A. reduced measles vaccine uptake during and after the COVID-19 pandemic. B. increased mask wearing and use of disinfectant when in hospital settings. €. improved immunisation programs in countries with high cases of measles. D. increased human contact with animals known to carry the measles virus.Page 14 of 44 Section A 2025 VCE (NHT) Biology Use the following information to answer Questions 23 and 24, Monoclonal antibodies can be used in the treatment of both autoimmune diseases and cancer. Question 23, monoclonal antibody ‘A. has a tertiary structure as its highest hierarchical level. B. has codons each containing three nucleotides. €. would contain amino acid monomers. D. has one polypeptide chain. Question 24 When used in the treatment of an autoimmune disease, monoclonal antibodies will A. attach to viral-infected cells. B. suppress an immune response. C. signal cytotoxic T cells to attack self-cells. D. increase the activity of antigen-presenting B cells. J 8 5 g 3 z 5 = Fa 2 Fy Ed2025 VCE (NHT) Biology Section A Page 15 of 44 Question 25, ‘Anew immunotherapy strategy for the treatment of some cancers uses chimeric antigen receptor (CAR) T cells. These cells are produced using the method shown below. Tell na Make CART coll in the lab Remove blood from t B insert gene for CAR patient togetT cells Sa, insert gene fo inserted gene ~ —_——+ Zr ~. us Tell \ chimeric fp — antigen A receptor carTco 1) (CAR) Toy ny | | ILS Grow millions of CART cells ee ; CAR T cells bind to cancer cells and kill them cancer cell iS x (| cancer cell Infuse CAR T cells into patient Source: Adapted from For the successful treatment of a cancer, the ‘A. gene inserted into CAR T cells must code for the production of antibodies that act against cancer cells. B. CART cells replace all other T cells within the body of the person with cancer. C. receptors on the CAR T cells must bind to a specific antigen on the cancer cells. D. CART cells act as phagocytes and engulf the cancer cells. FA Ss 5 2 Ps eS o EB 2 A r}Page 16 of 44 Section A 2025 VCE (NHT) Biology Use the following information to answer Questions 26 and 27. Helicobacter pylori are bacteria that infect the stomach lining. H. pylori are commonly treated with antibiotics. Some H. pylori are resistant to these antibiotics. A combination of antibiotics is often recommended. Without proper treatment, H. pylori infections can continue and lead to stomach ulcers and stomach cancer. The graph shows how H. pylori responded to five different antibiotics over two time periods in patients who were infected. Antibiotic resistance in Helicobacter pylori 60 40 resistant H. pylori strains (%) 20 0 — clarithromycin amoxicillin tetracycline metronidazole levofloxacin antibiotic name Key 2009-2010 Mi 2011-2012 ‘Source: An, Byoungrak, Moon, yung, Kin etal, “Anibote Resistance in Helicobacter nye Stans ans Effect on H.pyor Eradication Rates ina ‘Single Centar Kore, Annals of Laboratory Meivine, 3, 2013, p.416-B. Question 26 According to the graph, which two antibiotics show no change in percentage of resistant bacteria for the two time periods? A. amoxicillin and tetracycline B. amoxicillin and levofloxacin C. metronidazole and levofloxacin D. clarithromycin and metronidazole J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 17 of 44 Question 27 Based on the information provided, which of the following is most likely a consequence of antibiotic resistance after continued antibiotic treatment? A. Use of only tetracycline will reduce the duration of H. pylori infections. B. Use of only levofloxacin and clarithromycin will reduce bacterial resistance, keeping these antibiotics effective. . Use of only metronidazole and clarithromycin may increase the occurrence of ulcers and stomach cancers in the human population D. Use of only metronidazole and amoxicilin will not change the likelihood of patients developing ulcers and stomach cancers in the population. Use the following information to answer Questions 28 and 29. Ocean temperatures are rising, threatening coral reefs like the Great Barrier Reef. A selective breeding program is being trialled to develop heat-tolerant corals for reef recovery. The program involves: + identifying heat-tolerant parent corals * collecting spawn (eggs and sperm) from parent corals + mixing parent coral spawn, fertilisation occurring producing some heat-tolerant offspring + exposing coral offspring to high temperatures in the lab and eliminating those that are not heat-tolerant + testing survivors in the ocean to determine their suitability for reef recovery. Question 28 If this program successfully aids reef recovery, the long-term effect on the coral gene pool will be ‘A. increased genetic diversity due to the inclusion of a wider range of parent corals. B. unchanged, with a focus on maintaining existing genetic variation. C. increased genetic diversity, as many coral traits are being affected. D. increased occurrence of alleles that provide heat tolerance. Question 29 Itis important to test the coral offspring under ocean conditions in order to ‘A. accelerate the adaptation of corals to warmer ocean temperatures. B. ensure that offspring can survive natural environmental conditions. C. determine whether laboratory testing can be replaced by ocean testing D. optimise breeding methods by identifying heat-sensitive coral strains early in the process.Page 18 of 44 Section A 2025 VCE (NHT) Biology Use the following information to answer Questions 30 and 31. The diagram below depicts a geological cross-section of sedimentary rock layers in which groups of fossils have been discovered. Quaternary period a t 4 t ¥ Neogene period . @ Paleogene poriod tt mena # 58 Jurassic period @ 1 Question 30 Consider fossils found in the Jurassic period. Absolute dating has been used to date these fossils. Absolute dating relies on the A. law of superposition B. presence of an index fossil. C. decay of radioactive elements. D. presence of more than one type of fossil Question 31 Apalaeontologist uncovered four fossils within the same layer. G@e *F A The specific period in which fossil S existed is unknown. By analysing the time periods indicated by the arrows in the diagram and comparing the relative positions of the fossils found alongside it, the period fossil S existed can be inferred, In which period did fossil S exist? A. Quatemary B. Neogene C. Paleogene D. Cretaceous J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 19 of 44 Use the following information to answer Questions 32 and 33. Birds rely heavily on songs for communication, especially in mate selection. Indigobirds usually lay their eggs in the nests of firefinch birds. A study of indigobirds' offspring showed that they learn the mating song of the firefinch species. The scientists also noticed the following + As adults, male indigobirds mimic the firefinch mating song, + Adult indigobird females only select males that sing the same mating song they were raised with. + Indigobirds rarely lay their eggs in the nest of a species other than the firefinch. Question 32 If some female indigobirds lay their eggs in the nest of a different bird species, the consequences could be that over time itis likely that offspring will ‘A. fail to learn any song and will ikely not reproduce, preventing sympatric speciation. B. lear that new species’ song, leading to reproductive isolation and sympatric speciation, ._ leam that new species’ song and only mate with firefinch birds, leading to allopatric speciation D. only learn the indigobird song and only mate with indigobirds, isolating them, leading to allopatric speciation Question 33, Which of the following correctly shows the methodology used and appropriate data collected in the study of indigobirds? Methodology Data collected A. | case study blood sampling for hormone level analysis B. | fieldwork observing behaviour and recording of bird songs ¢. | controlled monitoring of reproductive success by counting the number of experiment eggs in anest D. | correlation study | DNA sequencing to find genetic similarities between hosts and indigobirdsPage 20 of 44 Section A 2025 VCE (NHT) Biology Question 34 Foot bones in the toes are called phalanges. In the images below, the phalanges of a human and a dog are compared. big toe upper phalange human ‘Souteos (tight): zinchonkiShutterstock om; kravka/Shutorstock com: boommaval’Shultorslock com: Henk Viosolaar/Shuttorstock com ‘The upper phalange of the dog corresponds to the big toe in humans. The upper phalanges in dogs may be considered an example of ‘A. selective breeding for homologous structures. B. molecular homology and vestigial structures. C. homologous and vestigial structures. D. structural and molecular homology. J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 21 of 44 Question 35, The chimpanzee-human divergence date is estimated at between 8 and 5 million years ago. An unclassified hominoid skull was discovered in Africa, dated at 7.2 to 6.8 million years old, The images show the underside of the skulls of a chimpanzee (Pan troglodytes), Australopithecus afarensis (dated at 3.7 to 3 million years old), modern human (Homo sapiens), and the unclassified skull (hominoid). The arrows point to the foramen magnum on each skull. Australopithecus Unclassified skull Pan troglodytes afarensis Homo sapiens (hominoid) ‘Sources: htps:iawm nature convscablaknowedgelibrary! Image of A. afarensis: htips:twawtnessm.edutiger/360views/Mominid_Skul-A_afarenss-composte_800x600/bottom him Referring to the unclassified skull of the hominoid, it is reasonable to conclude that the hominoid is most likely ‘A. not bipedal as the skull is dated at 7.2 to 6.8 million years old. B. bipedal as the foramen magnum is positioned towards the front of the skull, more similar to that of, the H. sapiens skull than the P. troglodytes skull C. not bipedal as the position of the foramen magnum does not align with that of either the H. sapiens skull or A. afarensis skull D. bipedal as the foramen magnum is positioned towards the back of the skull, more similar to that of the skulls of P. troglodytes and A. afarensis than the H. sapiens skullPage 22 of 44 Section A 2025 VCE (NHT) Biology Use the following information to answer Questions 36 and 37. Scientists found fossilised teeth and a fossilised humerus (upper arm) bone in Indonesia. The fossilised remains belong to an unknown hominin species (Species X). The fossils were dated at around 700000 years old. To determine the evolutionary relationship between Species X and other hominin species the teeth and humerus were compared to those of three other species, Homo erectus, Homo floresiensis and Homo sapiens. All species lived in Indonesia. The results are shown in the table below. Species X Age (years old) Teeth Humerus H. erectus ‘900000 similar different H. floresiensis 60000 different similar H. sapiens 55000 different | different Question 36 Referring to the information, itis reasonable to conclude that A. Species X may have evolved from H. erectus. B. Species X could be a putative species of H. erectus and H. floresiensis as they share similarities of both species, ©. _H- floresiensis or Species X should be classified as the same species as they both lived in Indonesia D. _H. sapiens and Species X are most closely related as the fossils were found recently. Question 37 The fossils were dated at around 700000 years old. The technique used to confirm this age of the fossils would be A. measuring the decay of carbon-14 isotopes in the humerus bone. B. DNAsequencing of the humerus bone. C. comparing previously discovered H. floresiensis fossils, such as teeth, as relative dating. D. dating of the rocks where the fossil was located, J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section A Page 23 of 44 Question 38, ‘The EPDR1 gene found on chromosome 7 helps control the contraction of muscle in the hand of humans. This gene has many alleles. Some of the alleles have a Neanderthal origin. ‘A Homo neanderthalensis fossil was located in Europe and dated to around 120000 years ago. The scientist discovered that the genome had an identical EPDR? allele to that found in some. individuals currently living in Europe. The findings indicate that A. H.neanderthalensis and H. sapiens are different species, therefore itis likely this EPDR1 allele would have an identical DNA sequence. B. the presence of this EPDR1 allele in today’s human population is evidence for H. neanderthalensis, interbreeding with H. sapiens ©. this EPDR1 allele is more likely to have arisen due to a mutation in H. sapiens. D. _H.neanderthalensis evolved in Europe before moving to Africa, as evidenced by the presence of this EPDR1 allele.Page 24 of 44 Section A 2025 VCE (NHT) Biology Use the following information to answer Questions 39 and 40. DNA sequencing of the human Y chromosome in individuals can provide evidence for the migration of human populations around the world In 2002, scientists recorded the numbers of short tandem repeats (STRs) on a section of the Y chromosome from individuals in South Asia and Aboriginal Australians. The scientists found similar STR variation between the groups, with divergence from a recent common ancestor dated at around 5000 years ago. In 2016, a repeat study was undertaken using improved DNA sequencing techniques and extended to include Papua New Guineans. Scientists constructed a phylogenetic tree from the results of the 2016 study. Human Y chromosome phylogeny Papua New Guinean Y chromosome Aboriginal Australian Y chromosome SO South Asian Y chromosome *) << SSSSSSSSSSsS present 27000 years ago 54000 years ago ‘Source: Adapted ftom A Bergstrom, N Nagle, Chen tal, ‘Osep root for Aboriginal Austalan Y chromosomes ‘Curent Biclogy, 25 (6) 2018, pp 809-813. Question 39 The results from the 2016 study most likely indicate that ‘A. Aboriginal Australians are more closely related to South Asians than Papuan New Guineans as they have a similar number of divergences. B. Aboriginal Australians are more genetically diverse compared to South Asians as they diverged around 50000 years ago. ©. South Asians had increased divergence around 27000 years ago and a new species of Homo sapiens may have evolved. D. Aboriginal Australians diverged from South Asians around 54.000 years ago with no recent common ancestor with South Asians at 5000 years ago. J 8 5 g 3 z 5 = Fa 2 Fy Ed2025 VCE (NHT) Biology Section A Page 25 of 44 Question 40 When comparing the two studies, itis reasonable to conclude that A. the 2002 and 2016 studies are not precise as different scientists carried out the DNA sequencing. B. the results of the 2002 study and 2016 study are invalid as the 2002 study recorded the number of STRs and the 2016 study constructed a phylogenetic tree, C. inthe 2016 study the data is more accurate than the 2002 study as improved DNA sequencing techniques were used. D. the results of the 2016 study do not represent the true value of the number of STRs as the true value was already determined in the 2002 study. FA Ss 5 2 Ps eS o EB 2 A r} End of Section APage 26 of 44 Section B 2025 VCE (NHT) Biology Section B Instructions + Answer all questions in the spaces provided + Write your responses in English. + Unless otherwise indicated, the diagrams in this book are not drawn to scale. Question 1 (7 marks) Tryptophan (trp), an amino acid, is an important part of cellular functions. Escherichia coll is a prokaryote naturally found within the human digestive system. The environment of E. coli partly depends on the food intake of its human host. When there are sufficient levels of trp in the environment, E. coli can absorb it from the surroundings. When there are insufficient trp levels, E. coli can produce their own. This production is regulated by an operon a, Depending on the food a person eats, E. coli can be exposed to high levels of trp on one day and low levels of trp on another day. Discuss the activity of the repressor protein for the trp operon in E. coli when they are in an environment with high levels of trp and low levels of trp. 4 marks b. Both humans and E. coli use mRNA and trp in biochemical pathways to produce proteins. Describe the function of both mRNA and t”p in the production of proteins, 3 marks J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section B Page 27 of 44 Question 2 (5 marks) Both human and yeast cells use glucose as an energy source but variations in biochemical pathways produce different products. (One variation in a biochemical pathway that occurs in human cells is shown below. glucose, ————— pyruvate. —————> actic acid a. Compare the biochemical pathway shown above to fermentation in yeast cells. 2marks b. Coenzymes are used in fermentation. Describe the general role of coenzymes in biochemical pathways. 3 marksPage 28 of 44 Section B 2025 VCE (NHT) Biology Question 3 (8 marks) Cavendish bananas make up around 97% of bananas grown in Australia. The plants can be affected by a disease, tropical race 4 (TR4), which causes the plant to wilt and die, The disease is caused by a fungus that remains in the soil for years and cannot be detected. The disease first appeared in 2015 in Norther Queensland and is now found on nine farms. The fungus is easily transmitted and there is no treatment for this disease. Source: 7Seven/Shuterstock com Australian scientists have found a wild variety of banana plant that is resistant to TR4 disease due to the RGA2 gene. Cavendish banana plants also have the RGA2 gene, but itis not functional. Both the wild variety and Cavendish banana plants are different subspecies of Musa acuminata, To transform the Cavendish bananas, plasmids from bacteria were used. An image of plasmids within a bacterium is shown below. receaioms {6 OO Source: Bany's beaut at/Shuttorstock com ‘The functional RGA2 gene from the wild variety of banana was isolated and then incorporated into a bacterial plasmid. a, Outline how an isolated functional RGA2 gene may be incorporated into a bacterial plasmid 3 marks J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section B Page 29 of 44 b. The functional RGA2 genes were transferred into the genomes of Cavendish banana cells using the plasmid. These banana cells then grew into Cavendish banana plants resistant to TR4 disease. The TR4-resistant Cavendish bananas are approved for food production in Australia. The bananas are considered safe and nutritious to eat. However, there are no immediate plans to grow the TR4-resistant Cavendish bananas ona large scale or sell them to consumers. i. Justify whether the TR4-resistant Cavendish banana plants are transgenic or genetically modified 2marks Infer three reasons why there are no plans for Australian farmers to grow ‘TR4-resistant Cavendish bananas on a large scale or to sell them to consumers. 3 marksPage 30 of 44 Section B 2025 VCE (NHT) Biology Question 4 (8 marks) ‘Swine flu is a respiratory disease caused by a type A influenza virus that mostly infects pigs and on rare occasions humans. The World Health Organization (WHO) is monitoring both animal and human cases of swine flu around the world. In 2023 there were several reported human cases of swine flu. These cases have not spread easily from person to person. a, The WHO is conducting an ongoing case study related to swine flu. Explain why a case study is an appropriate methodology for the WHO investigation. 2marks b. Swine flu causes an acute respiratory tract infection. The virus infects epithelial cells, along the airways and in the lungs. All nucleated body cells, including epithelial cells, have MHC Class | markers on their surface. Desoribe the function of the MHC Class | marker on an epithelial cell that is infected with the swine flu virus. 2 marks J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section B Page 31 of 44 ©. Dendritic cells play important roles in the initiation of the immune response in many animal species, including humans and pigs. Dendritic cells have both MHC Class | and MHC Class II markers, as shown in the diagram below. MHC Class | marker Dendritic cells can be split into types based on their structure and function. The table below shows relative amounts of MHC Class II markers and interferon produced by two different dendritic cell types. MHC Class Il markers Interferon Dendritic cell A high low Dendritic cell B low high Consider the information from the table above. Deseribe the different roles played by Dendritic cell Aand Dendritic cell B in an immune response. 4 marks Dendritic cell A. Dendritic cell 8Page 32 of 44 Section B 2025 VCE (NHT) Biology Question 5 (10 marks) Coxiella buretiid, a species of bacteria, can produce a disease called Q fever in humans. Humans can be infected when coming in contact with animals carrying C. burnetii. Animals that carry the bacteria include cattle, sheep and goats. Person-to-person spread of the pathogen is unlikely. ‘Symptoms of the disease develop two to three weeks after exposure to the bacteria. To determine if a person has the disease, a sample of blood is taken and tested for the presence of either antibodies against Q fever or the presence of C. burnetiid DNA. a, Outline the roles played by helper T cells in the adaptive immune response in a person with Q fever. b. The detection of the bacterial DNA in a patient's blood can involve the use of polymerase chain reaction (PCR). Explain how PCR is used to help identify the presence of the pathogen causing Q fever. ¢, Current studies in Australia suggest that only 10% of Q fever cases are identified. State one reason why 90% of Q fever cases are not being identified. d. Other than the development of a vaccine, state one strategy that could be implemented by the Australian Government to control the spread of Q fever. 3 marks 2marks 1 mark 1 mark J 8 5 g 3 z 5 = Fa 2 Fy Ed2025 VCE (NHT) Biology Section B Page 33 of 44 e, People in Victoria can access the National Immunisation Program (NIP), which provides a series of free vaccinations. However, immunisation against Q fever is not funded under the NIP. Using the information provided, infer why the NIP does not provide free vaccination against Q fever but does have free vaccinations for many infectious diseases 3 marks FA Ss 5 2 Ps eS o EB 2 A r}Page 34 of 44 Section B 2025 VCE (NHT) Biology Question 6 (13 marks) St Kilda is a remote island off the coast of Scotland, as shown in Figure 1. The island had a small, isolated human population originally from nearby Scottish islands. Harsh environmental conditions and a seasonal reliance on seabirds for food resulted in nutritional deficiencies. Minimal contact with the mainland and few visitors often led to food shortages. In 1940, the government relocated the population to Scottish towns on the mainland, In contrast, Lord Howe Island is a remote island off the coast of Australia. Its location is shown in Figure 2. The island was settled by people from diverse regions such as England, South Africa, Portugal and the Pacific. The island's favourable conditions led to tourism. from the 1900s and allowed for the growth of many different crops, which helped support the increasing human population. ae vee foe ced i g wali Foe Zo yore bap Soe men _ geMeoure : ee iano ‘Sanna j Human population over time 400 key 300 -@- St Kilda human = Lord Howe population 200 Island (number) Lo 100—"s = ae tet $--- 1700 1730 1760 1790 1820 1850 1880 1910 1940 1970 2000 year Source: P Stride, ‘Survvalof tne test a comparison of melcine and heath on Lord Howe Island and St Kida Journal Royal Collage Physicians Edinburgh, 40, 2010 a. Complete the table below with your prediction of the change in the genetic diversity in each population for the time period between 1790 and 1940. Justify your response. 4 marks Population Prediction Justification (increase, decrease, stay the same) St Kilda Lord Howe Island J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section B Page 36 of 44 b. _Inlate 1726, a resident of St Kilda made the three-day voyage to the Scottish mainland. During his time there, he contracted smallpox and died. The deceased man's clothing and personal items were returned to his family on St Kilda. Within 10 to 14 days of their return, a smallpox outbreak occurred, Account for the cause of the outbreak and explain its impact on St Kilda's human population. 3 marks ¢. Referring to a bioethical concept, explain why the decision to relocate the human population from St Kilda in 1940 could be seen as ethically justified 3 marks d. Explain how an antigenic shift in a virus on Lord Howe Island could pose a current public health threat. 3 marksPage 36 of 44 Section B 2025 VCE (NHT) Biology Question 7 (8 marks) Arecent study summarised the trend in brain size for Homo species over time. Data was obtained from 19 different studies over 90 years. The results are presented below with brain size measured as cranial capacity (om*). Cranial capacity of five Homo species 1458 1455 1459 1464 1500 1306 1304 1238 Key mya ~ millions 4000 of years ago cranial ya ~ years ago capacity (om*) 500: 0 Source: J DeSiva, LFannin et a, Frontiers in Ecology and Evolution, ‘1, 2023, 1191274 a. i. Describe the trend of hominin brain size, from Homo habilis to Homo sapiens (300000129000 years ago), with reference to data from the graph 2 marks . Discuss one advantage of the change in hominin brain size, over time, from Homo habilis to Homo sapiens (300 000-129 000 years ago). 2marks J 8 5 g 3 z 5 = Fa 2 Fy EdFA Ss 5 2 Ps eS o EB 2 A r} 2025 VCE (NHT) Biology Section B Page 37 of 44 b. The scientists completing the study concluded that the results for Homo sapiens (300000 to present) challenge current understandings of trends in hominin evolution. Justify this conclusion using data from the graph. 2marks At the end of the study, scientists suggested extending the investigation Recommend an extension to the investigation to improve the study, 2 marksPage 38 of 44 Section B 2025 VCE (NHT) Biology Question 8 (11 marks) The World Vegetable Centre (WorldVeg) collects, conserves and identifies important traits in vegetable plants. With this information, scientists are leading an initiative to increase both crop diversity and crop yield in Africa The scientists involved in WorldVeg investigated many different vegetable crops. They ‘employed advanced technology using an automated laser scanner. This scanner moves over fields of vegetable crops to capture 3D models of the plants under various conditions, allowing for the simultaneous assessment of multiple plant traits. The device scans plants three times a day, collecting as much data as 400 fieldworkers would collect in a 24-hour period The scanner can emit different wavelengths and intensities of light. The wavelengths reflected by the plants are one way in which data is obtained for analysis. The scanning technology enables the monitoring of many plants and helps identify those with desirable traits for vegetable crops. Plants can be exposed to different conditions such as flooding or heat stress, and the scanner can assess individual plants’ responses in real time. Plants responding well to the changed conditions can be identified, leading to the development of improved vegetable crops that are either heat- or flood-tolerant. Heat tolerance in a plant is a characteristic that results from a combination of traits. Scientists need to study many traits simultaneously to identify those traits that make a plant heat tolerant. Using the scanner, scientists evaluate 75 different traits, including plant height, biomass and leaf characteristics, throughout the plant's life cycle to select heat-tolerant varieties. Without the scanner, scientists would have to rely on only a few traits for selection and may miss important plant features. Once plants with desirable traits are identified, the plants are grown, and seeds are collected. In Africa the collected seeds are being distributed to African farmers. The farmers are encouraged to grow the seeds and produce crops with a higher yield. Source: Adaptes ftom N Paro, “Everything starts withthe seed’, Cosmas Magazine, 82, March, 2024, 46-55 a. Explain what useful information the scientists can determine about the plants of vegetable crops by measuring the reflected light wavelengths. 2marks b. State two pieces of data other than reflected wavelength that scientists collected about the plants to help determine their suitability for vegetable crops. 2marks J 8 5 g 3 z 5 = Fa 2 Fy Ed2025 VCE (NHT) Biology Section B Page 39 of 44 ¢. Referring to the information provided, outline two advantages of using this scanner over data collection by fieldworkers. 2marks d. In this study different crop species have been identified with adaptations that enable them to survive in hot, arid environments. Some of these adaptations are found in the photosynthetic pathways used by the plants. Compare the photosynthetic pathways found in C3 and CAM plants. Explain how the adaptations in CAM plants enable them to survive in hot, arid environments. 5 marks FA Ss 5 2 Ps eS o EB 2 A r}Page 40 of 44 Section B 2025 VCE (NHT) Biology Question 9 (10 marks) For one of their VCE Biology practical activities, a group of students investigated the relationship between biomass and stored carbon in different tree species. The biomass of a tree is a key indicator of how much carbon in the form of carbon dioxide (CO,) a tree has captured from the atmosphere. To estimate how much CO, a tree has captured, the students conducted fieldwork to measure the biomass of different trees. The students used a measuring tape to record the tree trunk’s circumference, which they then used to calculate the diameter of each tree. The students’ method is outlined below. Method: Identify the tree species. Measure the circumference (cm) of the trunk at a height of 1.4 metres. Caloulate the diameter of the trunk in cm Refer to the provided graph to estimate the tree's biomass (kg) based on the calculated diameter (om). The students were able to estimate the biomass of each tree using established relationships between the trunk diameter (om) and predicted biomass (kg) shown in the graph below. kena 4500 Blackbutt 4000 Eucalyptus pilularis: Mountain ash 3500 Eucalyptus regnans 3000 Brush box Lophostemon confertus 2500 River red gum predicted Eucalyptus camaldulensis iomass (kg) 2000 Pink bloodwood Corymbia intermedia 1500 1000 500 ot i 0 10 20 30 40 50 60 70 trunk diameter (cm) ‘Source: Adapted rom J 8 5 g 3 z 5 = Fa 2 Fy Ed2025 VCE (NHT) Biology Section B Page 41 of 44 a. Justify which tree species would be the most effective at capturing CO, from the atmosphere and storing it as carbon (biomass). 4 marks b. Describe two limitations of the method used by the students. 2marks State two safety precautions and/or ethical guidelines that should be followed by the students during the investigation while in the field 2 marks FA Ss 5 2 Ps eS o EB 2 A r} d. As the students were writing up their practical report, they began exploring real-world applications of their findings. The students completed a literature review. They discovered that scientists were investigating new technologies, such as CRISPR-Cas9, that could be used to improve the efficiency of photosynthesis in plants. Propose how CRISPR-Cas9 technology could improve the efficiency of photosynthesis. 2 marks End of examination questionsPage 42 of 44 2025 VCE (NHT) Biology Extra space for responses Clearly number all responses in this space. J co 5 g Ey s 5 = Fa 2 Fd Ed2025 VCE (NHT) Biology Page 43 of 44 ct 2 5 a rE = 2 = :} € 5 a Ifyou use any additional Question and Answer Books to complete your responses, write your student number on the front cover. At the end of the examination, place the additional Question and Answer Books inside the front cover of the first Question and Answer Book.© Victorian Curriculum and Assessment Authority 2025