Pearson Edexcel Level 1 /Level 2 GCSE (9-1 ) Time 1 hour 45 minutes Biology PAPER 1 Paper reference IBIO/IH Higher tier

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Instructions • Use black ink or ball-point pen. • Fill in the boxes at the top of this page with your name, centre number and candidate number. • Answer all questions. • Answer the quest ... ions in the spaces provided – there may be more space than you need. Information • The total mark for this paper is 100. • The marks for each question are shown in brackets – use this as a guide as to how much time to spend on each question. • In questions marked with an asterisk (*), marks will be awarded for your ability to structure your answer logically, showing how the points that you make are related or follow on from each other where appropriate. Advice • Read each question carefully before you start to answer it. • Try to answer every question. • Check your answers if you have time at the end. You must have: Ruler, calculator Biology PAPER 1 Higher tier Time 1 hour 45 minutes 1BI0/1H Pearson Edexcel Level 1/Level 2 GCSE (9–1) *P69319A0228* 2  Answer ALL questions. Write your answers in the spaces provided. Some questions must be answered with a cross in a box . If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 1 Gregor Mendel studied inheritance in pea plants. Pea plants can produce either yellow pea pods or green pea pods. Mendel crossed plants that always produce yellow pea pods with plants that always produce green pea pods. Symbol A represents the dominant allele. Symbol a represents the recessive allele. (a) Which is the genotype of the pea pods produced from this cross? (1) A AA B aa C Aa D YG (b) (i) Mendel grew many plants from the seeds in these pea pods. These plants were then crossed with each other. The seeds from this second cross produced 5496 plants with yellow pea pods and 1832 plants with green pea pods. Give this as a ratio in its simplest form. (1) ratio .............................................................. *P69319A0328* Turn over 3  (ii) Complete the Punnett square to show the outcome of a cross where both parent pea plants are heterozygous. Show the percentage probability of homozygous recessive offspring in your answer. (3) percentage probability of homozygous recessive offspring .............................................................. % (c) (i) Some plants reproduce sexually. Give one advantage of this type of reproduction. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (ii) Name the process that forms gametes for sexual reproduction. (1) .................................................................................................................................................................................................................................................................................... (Total for Question 1 = 7 marks) *P69319A0428* 4  2 (a) DNA molecules contain base pairs. Describe how the base pairs are bonded together in a DNA molecule. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (b) Figure 1 shows part of a DNA molecule. T T G A T T G C G T A A Figure 1 (i) Write the code for the complementary DNA strand in Figure 1. (2) (ii) Three bases code for each amino acid. Which is the maximum number of amino acids coded for by this strand of DNA? (1) A 3 B 4 C 6 D 12 (iii) What is the shape of a DNA molecule? (1) A triple stranded B single stranded C single helix D double helix *P69319A0528* Turn over 5  (c) A student wanted to extract the DNA from fresh peas. The student crushed the peas and added washing up liquid and water. The enzyme protease was then added to this mixture. (i) Explain why the enzyme protease was added to the mixture. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (ii) The mixture was then heated and filtered. Finally, the student poured the filtrate into a test tube and ice cold ethanol was poured down the side of the test tube into the filtrate. State why ice cold ethanol was poured into the filtrate. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (Total for Question 2 = 9 marks) *P69319A0628* 6  3 (a) Figure 2 shows the number of people diagnosed with sexually transmitted infections (STIs) in the UK during 2017. sexually transmitted infection (STI) number of people diagnosed per 1000 of the population chlamydia 3.7 gonorrhoea 0.8 genital herpes 0.6 genital warts 1.1 syphilis 0.1 Figure 2 (i) State the sexually transmitted infection that has the median number of people diagnosed. (1) .................................................................................................................................................................................................................................................................................... (ii) The population of the UK in 2017 was 66 million people. Calculate the total number of people diagnosed with chlamydia in the UK in 2017. (2) .............................................................. people (iii) State why chlamydia can be described as a communicable disease. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (iv) Give one way the transmission of chlamydia can be prevented. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... *P69319A0728* Turn over 7  (v) Explain why chlamydia can be treated with antibiotics. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (b) HIV is another sexually transmitted infection. Explain how HIV can lead to the onset of AIDS. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (Total for Question 3 = 9 marks) *P69319A0828* 8  4 (a) Figure 3 shows two light receptor cells from the human eye. cell A cell B X Y (Source: © Kokhanchikov/Shutterstock) Figure 3 (i) Which part of the eye contains light receptor cells? (1) A cornea B iris C lens D retina (ii) These cells require energy. The cell organelles labelled X release energy during respiration. Name the organelles labelled X. (1) .................................................................................................................................................................................................................................................................................... (iii) The cell organelle labelled Y contains chromosomes. Name the organelle labelled Y. (1) .................................................................................................................................................................................................................................................................................... (iv) Cell A responds to dim light and is responsible for night vision. Name cell A. (1) .................................................................................................................................................................................................................................................................................... *P69319A0928* Turn over 9  (v) Describe how the role of light receptor cell B is different from the role of light receptor cell A. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (b) The optic nerve carries information from the back of the eye to the brain. The optic nerve is 47mm in length. Nerve impulses travel at 75 metres per second. (i) Calculate the time an impulse takes to travel the length of the optic nerve. Use the equation: speed = distance time (3) .............................................................. seconds *P69319A01028* 10  (ii) The impulse travels to the occipital lobe of the brain. The occipital lobe is labelled in Figure 4. occipital lobe (Source: © Magic mine/Shutterstock) Figure 4 Which part of the brain contains the occipital lobe? (1) A cerebral hemispheres B medulla oblongata C cerebellum D hypothalamus (iii) State the sense most likely to be affected if the occipital lobe is damaged. (1) .................................................................................................................................................................................................................................................................................... (Total for Question 4 = 11 marks) *P69319A01128* Turn over 11  5 (a) In 2017, a new strain of Klebsiella pneumoniae bacteria was discovered that was resistant to 26 different antibiotics. (i) Explain how Klebsiella pneumoniae bacteria developed resistance to antibiotics. (4) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (ii) State how the use of antibiotics could contribute to Klebsiella pneumoniae bacteria developing resistance to antibiotics. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (iii) Klebsiella pneumoniae is a prokaryotic cell. Which is a characteristic feature of a prokaryotic cell? (1) A it has chloroplasts B it does not have a nucleus C it does not have ribosomes D it cannot reproduce without a host *P69319A01228* 12  (b) New antibiotics are being developed to treat the disease caused by Klebsiella pneumoniae. Describe the stages of antibiotic development [Show More]

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