Unit 5 Paper June 2004.Pdf

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Surname Centre Number Candidate Signature Other Names Candidate Number Leave blank General Certificate of Education June 2004 Advanced Level Examination BIOLOGY/HUMAN BIOLOGY (SPECIFICATION A) Unit 5 Inheritance, Evolution and Ecosystems Tuesday 22 June 2004 Morning Session No additional materials are required. You may use a calculator. BYA5 For Examiner’s Use Number 1 2 Mark Number Mark Time allowed: 1 hour 30 minutes Instructions • Use blue or black ink or ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions in the spaces provided. All working must be shown. • Do all rough work in this book. Cross through any work you do not want marked. Information • The maximum mark for this paper is 75. • Mark…show more content…
Meiosis Mitosis 1 Reduces the chromosome number Maintains the same chromosome number as in the parent nucleus 2 3 4 (3 marks) 5 Turn over APW/0204/BYA5 4 LEAVE MARGIN BLANK 3 Phytoplankton are microscopic photosynthesising organisms which live in water. In favourable environmental conditions they have a very high rate of reproduction. They are eaten by microscopic animals called zooplankton. In an investigation, samples of water were removed from a lake at intervals over a twelve-month period and the biomasses of these organisms were determined. The results are shown in the graph. Phytoplankton Biomass Zooplankton Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month The diagram shows the relationship between the biomass of the phytoplankton and the biomass of the zooplankton for one of the months during this investigation. Zooplankton Phytoplankton (a) Use the graph to give one month in which this relationship would have been found. ....................................................................................................................................................... (1 mark) APW/0204/BYA5 5 LEAVE MARGIN BLANK (b) Explain why the biomass of the primary consumers is less than the biomass of the producers in most communities. .......................................................................................................................................................
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