
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

GCE JAN 2010 : (AS 1) Molecules and Cells - Revised

21 pages, 38 questions, 0 questions with responses, 0 total responses,

	gce	+Fave Message
	Profile Timeline Uploads Q & A

Home > gce >

Instantly get Model Answers to questions on this ResPaper. Try now!
NEW ResPaper Exclusive!

Formatting page ...

Sp N ec e ifi w ca tio n Centre Number 71 Candidate Number ADVANCED SUBSIDIARy (AS) General Certificate of Education January 2010 Biology assessing Module 1: Molecules and Cells AB111 Assessment Unit AS 1 [AB111] TUESDAy 12 JANUARy, MORNING TIME 1 hour 30 minutes. INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of this page. Write your answers in the spaces provided in this question paper. Answer all eight questions. You are provided with Photograph 1.4 for use with Question 4 in this paper. Do not write your answers on this photograph. INFORMATION FOR CANDIDATES The total mark for this paper is 75. Section A carries 60 marks. Section B carries 15 marks. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. You are reminded of the need for good English and clear presentation in your answers. Use accurate scientific terminology in all answers. You should spend approximately 20 minutes on Section B. You are expected to answer Section B in continuous prose. Quality of written communication will be assessed in Section B, and awarded a maximum of 2 marks. For Examiner s use only Question Marks Number 1 2 3 4 5 6 7 8 Total Marks 5455.14 Section A 1 Examiner Only Marks Remark The diagram below shows a continuous flow reactor containing an immobilised enzyme. Substrate is poured into the reactor and product emerges at the other end. Substrate Immobilised enzyme Product (a) State what must be added with the substrate to control the pH during the process. _____________________________________________________ [1] (b) The product is checked for contamination by protein. Describe a biochemical test for the presence of protein. Your method must include a description of a positive result. _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _____________________________________________________ [3] (c) The product is a reducing sugar. State what reagent you would use to confirm a sugar has been produced. _____________________________________________________ [1] 5455.14 2 [Turn over 2 The diagram below shows two adjacent plant cells, A and B. The solute potential ( s) and pressure potential ( p) of both cells are given. A s = 400 kPa p = 100 kPa Remark B s = 200 kPa Examiner Only Marks p = 200 kPa (a) Write an equation which summarises the relationship between solute potential ( s), pressure potential ( p) and water potential ( cell) of a plant cell. _____________________________________________________ [1] (b) Water movement will take place between the two cells. In which direction will this movement take place? Explain your answer. _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _____________________________________________________ [3] (c) The pressure potential of cell B is higher than the pressure potential of cell A. Suggest one reason for the difference in the pressure potentials of the two cells. _______________________________________________________ _____________________________________________________ [1] 5455.14 3 [Turn over 3 The technique of DNA fingerprinting is based on the uniqueness of each person s genetic make-up. Enzymes are used to cut the DNA at specific points to create different sized fragments, e.g. EcoR1 recognises the base sequence GAATTC. These DNA fragments are separated by gel electrophoresis to create a series of bands. Because each person s DNA is different, each person s DNA will produce a different series of bands. Examiner Only Marks Remark (a) (i) Name the type of enzyme used to cut DNA into fragments. _________________________________________________ [1] (ii) Explain how different sized fragments are produced after this type of enzyme cuts the DNA. ___________________________________________________ ___________________________________________________ ___________________________________________________ _________________________________________________ [2] 5455.14 4 [Turn over The results of a DNA fingerprint can be used as evidence to link a suspect with a crime. The DNA fingerprints below show the bands obtained from DNA on a hair found at the crime scene along with those obtained from the DNA of three different suspects. Hair at crime scene Examiner Only Marks Remark Suspects A B C (b) Which suspect is most likely to have committed the crime? Explain your choice. _______________________________________________________ _______________________________________________________ _______________________________________________________ _____________________________________________________ [2] 5455.14 5 [Turn over 4 Photograph 1.4 is a section through the wall of a mammalian ileum. Examiner Only Marks Remark In the space below, draw a block diagram to show the tissue layers in the ileum wall as shown in the photograph. Label the drawing to identify at least five structures. [10] 5455.14 6 [Turn over 5 The diagrams below represent the structure of an enzyme with its associated substrates and the same enzyme after the addition of both a competitive and a non-competitive inhibitor. Examiner Only Marks Remark A C B (a) Identify the part of the enzyme labelled A. _____________________________________________________ [1] (b) (i) Which of the two inhibitors, B or C, is a competitive inhibitor? _________________________________________________ [1] (ii) Explain your reasoning for your answer in part (i). ___________________________________________________ ___________________________________________________ ___________________________________________________ _________________________________________________ [2] 5455.14 7 [Turn over The graph below illustrates the effect of substrate concentration on the rate of an enzyme-controlled reaction with no inhibitor present. The effects of the addition of a competitive inhibitor and of a non-competitive inhibitor are also shown. Examiner Only Marks Remark no inhibitor Rate of reaction competitive inhibitor non-competitive inhibitor Substrate concentration (c) Describe and explain the effect of substrate concentration on the rate of reaction for the enzyme with no inhibitor added. _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _____________________________________________________ [3] 5455.14 8 [Turn over (d) (i) Describe the effects of each of the two inhibitors. Examiner Only Marks Remark Competitive inhibitor ___________________________________________________ ___________________________________________________ Non-competitive inhibitor ___________________________________________________ _________________________________________________ [2] (ii) Explain how an increase in substrate concentration influences the effect of the competitive inhibitor. ___________________________________________________ ___________________________________________________ ___________________________________________________ _________________________________________________ [2] 5455.14 9 [Turn over 6 The diagram below shows a yeast (fungal) cell in the process of producing a daughter cell by budding. Examiner Only Marks Remark A B Used with the permission of Nelson Thornes, Bath. Advanced Science Biology isbn 978 0 17 438425 0 first printed in 2002 (a) (i) Identify structures A and B in this cell. A __________________________________________________ B _______________________________________________ [2] (ii) State two features, other than A and B, which show that this cell is eukaryotic. 1. _________________________________________________ ___________________________________________________ 2. _________________________________________________ _________________________________________________ [2] 5455.14 10 [Turn over The diagram below shows features of the human immuno-deficiency virus, HIV. Examiner Only Marks Remark Reverse transcriptase A B (b) (i) Identify the chemical nature of the structures A and B. A _________________________________________________ B _______________________________________________ [2] (ii) State the role of the enzyme reverse transcriptase in HIV. ___________________________________________________ ___________________________________________________ ___________________________________________________ _________________________________________________ [2] (c) Budding in yeast is a means by which a yeast cell reproduces. (i) Suggest what type of nuclear division produces the genetically identical daughter cell. _________________________________________________ [1] (ii) Suggest why it is not possible for a virus to produce a bud. ___________________________________________________ ___________________________________________________ ___________________________________________________ _________________________________________________ [2] 5455.14 11 [Turn over 7 Paper chromatography can be used to separate a mixture of amino acids. When trypsin, a protease enzyme, was incubated with a protein, a mixture of amino acids was produced. The diagram below shows the separation of the amino acids in a chromatogram. Three known amino acids were spotted on the paper as part of the procedure. Examiner Only Marks Remark Solvent front 65 mm 100 mm A x x x x methionine lysine phenylalanine mixture (a) Using the information in the chromatogram answer the following: (i) State how many different types of amino acid were present in the protein. _________________________________________________ [1] (ii) State the identity of any of the amino acids in the mixture. _________________________________________________ [1] (iii) Calculate the Rf value for the amino acid A, using the measurements shown on the chromatogram. (Show your working.) Answer _____________________ [1] 5455.14 12 [Turn over (b) Describe the procedure used to develop the chromatogram, during which the spots are stained. Examiner Only Marks Remark _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _____________________________________________________ [3] The first biological detergent contained a protease enzyme, which removed protein-based stains, such as egg and blood. (c) (i) State the type of reaction catalysed by the protease enzyme. _________________________________________________ [1] In later years amylase and lipase were added to biological detergents to remove a wider variety of stains. (ii) Triglycerides are removed by lipase. State the products of this reaction. _________________________________________________ [1] (iii) Explain why it is difficult to produce a detergent containing a mixture of enzymes which includes protease. ___________________________________________________ ___________________________________________________ ___________________________________________________ _________________________________________________ [2] 5455.14 13 [Turn over Cellulase has been added to biological detergents as a means of restoring the fabric in clothes which contains cotton. Cellulase digests any loose and damaged cellulose microfibrils from cotton fibres restoring the original smooth surface. Examiner Only Marks Remark (d) Using your knowledge of starch and cellulose structure, explain why a starch stain can be completely removed by amylase whereas only the loose cellulose microfibrils are removed from the surface of the cotton fibres. _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _____________________________________________________ [3] 5455.14 14 [Turn over Section B Examiner Only Marks Quality of written communication is awarded a maximum of 2 marks in this section. 8 Remark [2] (a) Describe the behaviour of the chromosomal material during a cell cycle involving mitosis. [8] (b) Describe how the behaviour of chromosomes differs during the processes of mitosis and meiosis. Explain the consequences of these differences. [5] _________________________________ (a) Describe the behaviour of the chromosomal material during a cell cycle involving mitosis. _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ 5455.14 15 [Turn over Examiner Only Marks Remark _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ 5455.14 16 [Turn over (b) Describe how the behaviour of chromosomes differs during the processes of mitosis and meiosis. Explain the consequences of these differences. _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ _______________________________________________________ 5455.14 17 Examiner Only Marks Remark THIS IS THE END OF THE QUESTION PAPER 5455.14 18 [Turn over 5455.14 20 [Turn over Sp N ec e i w ca tio n GCE Biology Advanced Subsidiary (AS) Assessment Unit AS 1 Module 1: Cell Biology January 2010 Photograph 1.4 (For use with Question 4) Manfred Kage/Science Photo Library *AB111INS1* AB111INS1 5455.15

Formatting page ...

Additional Info : Gce Biology January 2010 Assessment Unit AS 1 Molecules and Cells
Tags : General Certificate of Education, A Level and AS Level, uk, council for the curriculum examinations and assessment, gce exam papers, gce a level and as level exam papers , gce past questions and answer, gce past question papers, ccea gce past papers, gce ccea past papers

gce chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: