OCR Oxford Camtxidge and RSA Wednesday 15 June 2022 — Morning GCSE (9—1) Combined Science (Biology) A (Gateway Science) J250/08 Paper 8 (Higher Tier) Time allowed: 1 hour 10 minutes

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INSTRUCTIONS • Use black ink. You can use an HB pencil, but only for graphs and diagrams. • Write your answer to each question in the space provided. If you need extra space use the lined page... s at the end of this booklet. The question numbers must be clearly shown. • Answer all the questions. • Where appropriate, your answer should be supported with working. Marks might be given for using a correct method, even if your answer is wrong. INFORMATION • The total mark for this paper is 60. • The marks for each question are shown in brackets [ ]. • Quality of extended response will be assessed in questions marked with an asterisk (*). • This document has 24 pages. ADVICE • Read each question carefully before you start your answer. *8995733086* © OCR 2022 [601/8687/2] DC (CJ/FC) 300164/9 *J25008* You must have: • a ruler (cm/mm) You can use: • a scientific or graphical calculator • an HB pencil Wednesday 15 June 2022 – Morning GCSE (9–1) Combined Science (Biology) A (Gateway Science) J250/08 Paper 8 (Higher Tier) Time allowed: 1 hour 10 minutes 2 © OCR 2022 SECTION A Answer all the questions. You should spend a maximum of 20 minutes on this section. Write your answer to each question in the box provided. 1 The diagram shows a genetic cross for seed shape in peas. RR Rr R R Round seed Key Wrinkled seed r rr r Rr Which prediction about the offspring is most likely? A All the offspring will be heterozygous for seed shape. B All the offspring will be homozygous for seed shape. C The ratio of heterozygous to homozygous offspring will be 1:1. D The ratio of heterozygous to homozygous offspring will be 3:1. Your answer [1] 2 The diameter of a human ovum is 100 000 nm. The diameter of the HIV pathogen is 100 nm. How many orders of magnitude larger is the diameter of a human ovum compared to an HIV pathogen? A 3 B 10 C 99 D 1000 Your answer [1] 3 © OCR 2022 Turn over 3 Which term describes all the different organisms living in an environment? A Community B Ecosystem C Population D Species Your answer [1] 4 Which number per cell is halved during meiosis? A Chromosome B Gamete C Haploid D Nucleus Your answer [1] 4 © OCR 2022 5 HIV is spreading rapidly in many countries. Which method is used to screen for the HIV virus in a person with no symptoms? A Detection of the HIV antigen B Detection of white blood cells C DNA testing for TB D Visual identification Your answer [1] 6 Which substance in the blood plasma is changed by platelets during blood clotting? A Fat B Glucose C Glycogen D Protein Your answer [1] 7 What medicine can be used to treat HPV? A Antibiotics B Antiseptics C Antitoxins D Antivirals Your answer [1] 5 © OCR 2022 Turn over 8 The diagram shows the classification of the brown bear and its relationship with other species. KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos Which classification group would show the most similarities in DNA sequencing? A Class B Family C Genus D Order Your answer [1] 6 © OCR 2022 9 Scientists that genetically engineer bacteria need to identify those bacteria that have taken up the modified plasmid. What is used to identify bacteria that have taken up the modified plasmid? A Antibiotic resistant genes B Ligases C Restriction enzymes D Vectors Your answer [1] 7 © OCR 2022 Turn over 10 When one species splits to become two new separate species it is called a speciation event. Phylogenetic trees represent speciation events from the past. The diagram shows a phylogenetic tree. Species 5 Species 4 Species 3 Time Species 2 Species 1 How many speciation events are in this phylogenetic tree? A 1 B 2 C 3 D 4 Your answer [1] 8 © OCR 2022 SECTION B Answer all the questions. 11 Two students investigate the population of daisies in a lawn. The diagram shows the lawn in front of a shed. 5 m 3 m (a) (i) Complete these sentences about the method the students use to find the population of daisies. Use the words in the list. pooter quadrat random square The lawn is sampled using a square frame called a ...................................... . Drop the square frame over one shoulder to provide a ........................................ sample. Count and record the number of daisy plants present in the square grid. Repeat this process in 10 different areas of the lawn. [2] (ii) Table 11.1 shows their results. Table 11.1 Square frame 1 2 3 4 5 6 7 8 9 10 Total Number of daisies counted 14 3 8 10 16 15 11 10 11 12 110 Estimate the population of daisies in the lawn. • The students used a 0.5 m × 0.5 m frame to sample the lawn. • The lawn size is 5 m × 3 m. Estimate of population of daisies in the lawn = .......................................................... [3] 9 © OCR 2022 Turn over (b) The students develop their investigation to show how the shed affects where daisies grow in the lawn. Table 11.2 shows the results. Table 11.2 Distance from shed (m) Number of daisies 1.0 0 1.5 2 2.0 4 2.5 6 3.0 8 3.5 10 4.0 12 4.5 14 5.0 16 (i) Plot a line graph of the results from Table 11.2. Draw a straight line of best fit. [4] (ii) Use the graph to determine the slope of the line. Slope = ......................................................... [1] 10 © OCR 2022 (iii) Daisy plants require lots of light. Explain the effect of the shed on the growth of daisies in the lawn. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2] 11 © OCR 2022 Turn over 12 (a) Complete these sentences about different factors that affect the ecosystem. Use the words or phrases in the list. abiotic biotic carbon dioxide food oxygen pH in soil predators temperature Living organisms affecting the ecosystem are known as ...................................... factors. Physical factors that affect living organisms are described as ...................................... factors. Physical factors that can directly affect the rate of photosynthesis include ...................................... and ...................................... concentration. [3] (b) A student investigates the relationship between bean plants and the bacteria that live in the roots of the bean. They think the bacteria live inside root nodules. Fig. 12.1 shows root nodules on a bean plant. Fig. 12.1 Root nodule 12 © OCR 2022 The student takes a thin section of the nodule and looks at it under a light microscope. Fig. 12.2 shows bacteria inside the root nodule. Fig. 12.2 (i) Describe how to take a thin section of the nodule and prepare it to view under a light microscope. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [3] (ii) The bacteria were not visible clearly using a light microscope. The student found an image taken using a different type of microscope. Fig. 12.3 shows this imag [Show More]

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