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

GCE JAN 2008 : (AS 1) Cell Biology

17 pages, 33 questions, 0 questions with responses, 0 total responses,

	gce	+Fave Message
	Profile Timeline Uploads Q & A

Home > gce >

Formatting page ...

Centre Number 71 Candidate Number ADVANCED SUBSIDIARY (AS) General Certificate of Education January 2008 Biology assessing Module 1: Cell Biology ASB11 Assessment Unit AS 1 [ASB11] TUESDAY 15 JANUARY, AFTERNOON TIME 1 hour. 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 1.3 for use with Question 3 in this paper. Do not write your answers on this photograph. For Examiner s use only Question Number 1 INFORMATION FOR CANDIDATES The total mark for this paper is 55. Section A carries 43 marks. Section B carries 12 marks. You should spend approximately 15 minutes on Section B. You are expected to answer Section B in continuous prose. Quality of written communication will be assessed in Section B. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. 2 3 4 5 6 7 8 Total Marks ASB1W8 3310 Marks Section A Examiner Only Marks 1 Remark Read the following passage on the cell cycle, and write the most appropriate word in the blank spaces to complete the account. Actively dividing eukaryotic cells go through a process called the cell cycle. During __________________ there are intense periods of growth within which there is a __________________ phase when DNA replication occurs. Nuclear division is known as __________________ during which four phases are recognised. In the first of these the chromosomes shorten and thicken, and each is seen to consist of a pair of chromatids. In the next phase, known as __________________, the chromosomes assemble across the equatorial plane, and this is followed by a phase during which two nuclei form. __________________ follows nuclear division and involves the division of cytoplasm and the formation of two daughter cells. ASB1W8 3310 2 [4] [Turn over 2 Diffusion and facilitated diffusion are two ways by which substances cross the cell-surface membrane. Examiner Only Marks Remark (a) State one difference and one similarity between diffusion and facilitated diffusion. Difference ____________________________________________ _____________________________________________________ Similarity ____________________________________________ _____________________________________________________ [2] Ascorbic acid (vitamin C) and calciferol (vitamin D) are required for normal cellular metabolism and it is essential that both are able to enter cells. However, they take different routes across the cell-surface membrane since ascorbic acid is water-soluble while calciferol is lipid-soluble. (b) Explain how the structure of the cell-surface membrane determines the route taken by each of these vitamins. Ascorbic acid _________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ Calciferol _____________________________________________ ________________________________________________________ ________________________________________________________ _____________________________________________________ [4] ASB1W8 3310 3 [Turn over 3 Photograph 1.3 is an electron micrograph of part of a eukaryotic cell. Examiner Only Marks Remark (a) Identify the features labelled A to D. A ___________________________________ B ___________________________________ C ___________________________________ D ___________________________________ [4] (b) State two differences in structure between a eukaryotic cell and a prokaryotic cell. 1. ______________________________________________________ _________________________________________________________ 2. ______________________________________________________ ______________________________________________________________ [2] ASB1W8 3310 4 [Turn over 4 The enzyme lipase catalyses the following reaction. Examiner Only Marks Remark lipase Lipid _________________ + fatty acids (a) Complete the equation above to show the missing product. [1] (b) Name the type of reaction that lipase is shown to be catalysing above. ______________________________________________________________ [1] In an experiment into the action of lipase at three temperatures, the pH of the reaction mixture was measured after a period of time. The results are shown in the table below. In each case, the initial pH of the reaction mixture was 7. Temperature at which the reaction mixture was incubated/ C pH of reaction mixture after 60 minutes 5 6.9 35 6.2 65 7.0 (c) Explain the decrease in pH when the reaction mixture was incubated at 35 C. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ ______________________________________________________________ [2] (d) Explain the relative inactivity of lipase at each of the other two temperatures. 5 C ________________________________________________________ _____________________________________________________________ 65 C _______________________________________________________ __________________________________________________________ [2] ASB1W8 3310 5 [Turn over 5 In an experiment on osmosis in plant tissues, cylinders of potato were immersed in solutions of different solute potential for the same period of time. The initial and final lengths of the potato cylinders were measured, and the final length calculated as a percentage of the initial length. The results are shown in the graph below. Examiner Only Marks Remark 120 110 Final length 100 as a percentage of initial length 90 80 2000 1600 1200 800 400 0 Solute potential of immersing solution/kPa (a) Explain the change in length of the potato cylinder immersed in a solution of solute potential 2000 kPa. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ ______________________________________________________________ [3] (b) Use the graph to determine the solute potential of the solution in which the length of the potato cylinder remained the same. ______________________________________________________________ [1] ASB1W8 3310 6 [Turn over (c) The initial length of a potato cylinder was 80 mm. Calculate its final length (in mm) after immersion in a solution of solute potential 400 kPa. (Show your working in the space below.) Examiner Only Marks Remark Final length _________ mm [2] ASB1W8 3310 7 [Turn over 6 The diagram below represents the structure of a nucleotide of DNA. Examiner Only Marks Remark A base B (a) Name the parts labelled A and B. A ___________________________________ B ___________________________________ [2] (b) The table below shows the percentage composition of bases in the DNA of a number of species. Species Adenine Cytosine Guanine Thymine E. coli (a bacterium) 24 26 26 24 Yeast 32 18 18 32 Salmon 29 21 21 29 Pig 29 21 21 29 Human 30 Examiner Only (i) Complete the table to show the percentage of cytosine, guanine and thymine that you would expect for human DNA. Explain how you arrived at the answers provided. Marks Remark ______________________________________________________ ________________________________________________________ ________________________________________________________ _____________________________________________________ [3] ASB1W8 3310 8 [Turn over (ii) The salmon has the same percentages of the four bases as the pig. Explain why they are still going to be very different animals producing their own specific proteins. Examiner Only Marks Remark ______________________________________________________ ________________________________________________________ ________________________________________________________ _____________________________________________________ [2] ASB1W8 3310 9 [Turn over 7 The protein, somatostatin, consists of a single short chain of 14 amino acids. Ala Gly A Cys Lys Phe Asn Remark Phe Trp S S Cys Examiner Only Marks Lys Ser Thr Phe Thr (a) (i) Name the type of bond shown at A. ____________________________________ [1] (ii) Explain why somatostatin is described as a tertiary protein. ________________________________________________________ _____________________________________________________ [1] Genetic engineers make the gene which codes for this protein by assembling nucleotide pairs. (b) How many nucleotide pairs would be needed for the synthesis of this gene? ______________________________________________________________ [1] The synthesised gene coding for the protein has nucleotides added to each strand at opposing ends to produce sticky ends. (c) Explain why the sticky ends are advantageous. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ ______________________________________________________________ [2] ASB1W8 3310 10 [Turn over This protein is of medical importance and can be produced by genetically engineered bacteria. The gene which codes for somatostatin is inserted into a plasmid which acts as a vector. Examiner Only Marks Remark (d) Describe how the gene coding for somatostatin is inserted into a plasmid. _________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ ______________________________________________________________ [3] ASB1W8 3310 11 [Turn over Section B Examiner Only Marks Remark In this section you are expected to answer in continuous prose, supported, where appropriate, by diagrams. You are reminded that up to two marks in this question are awarded for the quality of written communication. [2] 8 Give an account of the structural and functional differences between animal and plant cells. [10] ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ASB1W8 3310 12 [Turn over Examiner Only ____________________________________________________________ Marks Remark ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ASB1W8 3310 13 [Turn over THIS IS THE END OF THE QUESTION PAPER S 3/07 302-027-1 GCE Biology Advanced Subsidiary (AS) Assessment Unit AS 1 Module 1: Cell Biology January 2008 Photograph 1.3 (For use with Question 3) A B C C Source: Dr Gopal Murti, Science Photo Library 30 m ASB1W8 3310.02 ASB11IN1 D

Formatting page ...

Additional Info : Gce Biology January 2008 Assessment Unit AS 1 Module 1: Cell Biology
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: