Edexcel a level biology a question paper 1 june 2023 salters Nuffield + mark sche me

Please check the examination details below before entering your candidate information Candidate surname Other names Centre Number Candidate Number Pearson Edexcel Level 3 GCE Wednesday 7 June 2023 Afternoon (Time: 2 hours) Paper reference 9BN0/01 Total Marks Biology A (Salters Nuffield) Advanced PAPER 1: The Natural Environment and Species Survival You must have: Scientific calculator, HB pencil, ruler 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. • Show all your working out in calculations and include units where appropriate. • Answer the questions 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. • You may use a scientific calculator. • 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.*P71906A0232* DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA 2  Answer ALL questions. 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 Homo sapiens is the only living species of the genus Homo. Over 100 000 years ago, Homo neanderthalensis, a species closely related to modern humans, lived with other Homo species in the same habitat. (a) Which of the following is the correct definition of the term habitat? (1) A a group of organisms of different species living in the same area B a group of organisms of the same species living in the same area C a place where an organism lives D the role of an organism (b) A fossil bone discovered in China is thought to be from a new species, Homo longi. (i) Samples of DNA from this bone and bones from other Homo species can be amplified using PCR. Describe how these amplified samples of DNA can be prepared for analysis using gel electrophoresis. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... *P71906A0332* Turn over 3 DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA (ii) Explain how the results of this analysis would show whether Homo longi is closely related to other Homo species. 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(Total for Question 1 = 6 marks)*P71906A0432* DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA 4  2 Human activities are affecting many habitats. These activities can change the biodiversity of communities and populations within a habitat. (a) Which of the following describes biodiversity within a habitat? (1) A the number of different alleles and the number of the same species B the number of different species and the number of different alleles C the number of different species and the number of the same alleles D the number of the same alleles and the number of the same species (b) Brown Moss is a site of special scientific interest. It is an area containing shallow ponds, inhabited by birds and rare plants. The biodiversity of plants growing in two ponds, A and B, at Brown Moss was studied. The table includes data collected from the two ponds. Species Number (n) in pond A n(n–1) for pond A Number (n) in pond B n(n–1) for pond B Azolla filiculoides 5 20 0 0 Lemna minuta 29 812 0 0 Lemna trisulca Alisma plantago-aquatica 2 2 0 0 Alopecurus aequalis 11 110 0 0 Carex pseudocyperus 2 2 0 0 Equisetum fluviatile Juncus effusus Menyanthes trifoliata 16 240 0 0 Polygonum amphibium 0 0 25 600 Ranunculus circinatus 13 0 0 Sparganium erectum 3 6 0 0 Typha latifolia 5 20 0 0 Total 156 9 110 (i) Complete the table for pond A giving the value for n(n–1) for Ranunculus circinatus and give the totals. (1) *P71906A0532* Turn over 5 DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA (ii) Calculate the index of diversity for pond B using the formula D N N n n = - å - ( ) ( ) 1 1 (2) Answer .............................................................. (iii) Pond B is close to a farm and some houses. Chemicals and waste from the farm and houses have increased the levels of pollutants in pond B. The biodiversity index for pond A is 4.81. Comment on the effect of pollutants on the biodiversity of pond B. 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(Total for Question 2 = 7 marks)*P71906A0632* DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA 6  3 The genetic information for a cell is stored in the DNA. (a) Describe the structure of a DNA mononucleotide. (2) ...................................................................................................................................................................................................................................................................................