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ARHOLIADAU EXAMINATIONS
SEMESTER 1 EXAMINATIONS 2011
IBERS (BIOLOGICAL SCIENCES)
BS13510 BIOLOGY OF THE CELL
TIME ALLOWED: TWO HOURS
ANSWER ALL MULTIPLE CHOICE QUESTIONS FROM SECTION A. ANSWER
QUESTION 1 FROM SECTION B, AND ANSWER FIVE OTHER QUESTIONS
FROM SECTION B IN THE SPACES PROVIDED ON THE QUESTION PAPER
Rhif Cyfeirio’r Myfyriwr/ Student Reference Number: ……………………………………………
Dyddiad/Date ………………………………………………
Ystafell Arholiad/Examination Room ………………………………………………
Rhif y Sedd/Seat Number ………………………………………………
- Rhowch y wybodaeth angenrheidiol yn y blychau uchod a rhowch eich enw yn y man gwag ar dop y tudalen ar y dde. Plygwch a seliwch y cornel ochr dde ar dop y tudalen (gan ddefnyddio’r slip gludiog a ddarperir) er mwyn cuddio eich enw.
- Rhaid i’r atebion fod wedi eu hysgrifennu’n glir. Gall yr Arholwyr nail ai anwybyddu sgript annealladwy, neu drefnu i’w theipio a chael yr ymgeisydd i gwrdd â chost y gwaith.
- Ysgrifennwch eich atebion mewn inc.
- Ni ddylid torri allan unrhyw ran o’r llyfr hwn; rhaid ei ddychwelyd mewn ffurf gyflawn.
- Os ymadewch â’r ystafell arholi yn gynnar, gwnewch hynny’n dawel os gwelwch yn dda rhag aflonyddu ar ymgeiswyr eraill. 1. Please give the information requested above and enter your name in the space provided at the top right of this page. If your answers are to be marked under a scheme approved by the College whereby the examiners will not know your identity, fold over and seal down the top right-hand corner (using the gummed slip provided) in order to conceal your name. 2. The answers must be legibly written. The Examiners can either ignore illegible script or have it typed and the expense of typing charged to the candidate. 3. Write your answers in ink. 4. This paper must be handed in complete. 5. If you leave the examination early, please do so quietly so as not to disturb other candidates.
Fold over and stick down/plygwch y gornel drosodd
Cyfenw/Surname.............................................
Enwau Cyntaf/ Forenames ......................................................
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ANSWER ALL MULTIPLE CHOICE QUESTIONS (Section A) ON THE SEPARATE COMPUTER SHEET
USE OF CALCULATORS IS ALLOWED
INSTRUCTIONS FOR MULTIPLE CHOICE QUESTIONS
Answer all multiple choice questions on one optically marked sheet. You must answer each question in the order in which it appears on the question paper.
Complete the boxes on the optically marked sheet to give the following details - name, date, subject, module identifier and student number.
Student number should be completed by writing the digits in pencil in the top line of the box and then filling in the bar code boxes below with the first digit represented in column 1 , the second digit in column 2 and so on. This is done by striking through the little box with a soft pencil as shown in the instructions on the sheet for marking the correct answers. Other instructions are on the sheet, but note the following:-
There are five possible answers to each question, only one of them is correct.
Record your answers on the optically read sheet by using a soft pencil (HB or softer) to mark the appropriate box thus: Do not tick, cross or ring boxes and do not write elsewhere on the form.
1 mark is given for every correct answer. No marks added/deducted for incorrect answers. No marks added/deducted for blank answers.
If you make a mistake on the optically marked sheet, it can be corrected with a soft eraser.
Spare sheets are available in the examination hall.
Text B. Proteins that have hydrophobic domains that are inserted into the plasma membrane are referred to as X membrane proteins. They may cross both leaflets (layers) of the plasma membrane. Alternatively their hydrophobic domains may insert into only one leaflet in which case they are termed Y. In contrast, proteins that associate with the plasma membrane as a result of non-covalent interactions with lipid headgroups or other plasma membrane proteins are known as Z.
- Read text B. This question asks you to replace an underlined letter in text B with a
word or phrase chosen from the list below. Which word or phrase would you choose to replace X? a) Extrinsic. b) Integral. c) GPI-linked. d) Monotypic. e) Peripheral.
- Read text B. This question asks you to replace an underlined letter in text B with a word or phrase chosen from the list below. Which word or phrase would you choose to replace Y? a) Extrinsic. b) Integral. c) GPI-linked. d) Monotypic. e) Peripheral.
- Read text B. This question asks you to replace an underlined letter in text B with a word or phrase chosen from the list below. Which word or phrase would you choose to replace Z? a) Extrinsic. b) Integral. c) GPI-linked. d) Monotypic. e) Peripheral.
Figure 1
- Look at figure 1. This shows an unlabelled graph of diffusion. What type of diffusion is
shown by this graph? a) Active. b) Direct. c) Facilitated. d) Indirect. e) Passive.
- Look at figure 1. This shows an unlabelled graph of diffusion. What does the X axis
indicate? a) Concentration difference. b) Distance diffused. c) Rate of uptake. d) Temperature. e) Time.
- Look at figure 1. This shows an unlabelled graph of diffusion. What does the Y axis represent? a) Concentration difference. b) Distance diffused. c) Rate of uptake. d) Temperature. e) Time.
Text C. The extracellular matrix (ECM) of cells consists of a matrix consisting largely of X. Embedded into the matrix are two main types of fibres. Y fibres are arranged in bundles and give the ECM its strength. Z fibres can stretch and relax giving the ECM flexibility.
- Read text C. This question asks you to replace an underlined letter in text C with a word or phrase chosen from the list below. Which word or phrase would you choose to replace X? a) Cadherin. b) Collagen. c) Elastin. d) Integrin. e) Proteoglycan.
- Read text C. This question asks you to replace an underlined letter in text C with a word or phrase chosen from the list below. Which word or phrase would you choose to replace Y? a) Cadherin. b) Collagen. c) Elastin. d) Integrin. e) Proteoglycan.
- Read text E. This question asks you to replace an underlined letter in text E with a word or phrase chosen from the list below. Which word or phrase would you choose to replace X? a) Annuli. b) Desmosomes. c) Nucleoli. d) Nucleosomes. e) Ribosomes.
- Read text E. This question asks you to replace an underlined letter in text E with a word or phrase chosen from the list below. Which word or phrase would you choose to replace Y? a) Ala and Gly b) Arg and Lys. c) Ser and Thr. d) Trp and His. e) Tyr and Phe.
- Read text E. This question asks you to replace an underlined letter in text E with a word or phrase chosen from the list below. Which word or phrase would you choose to replace Z? a) Euchromatin. b) Heterochromatin. c) Homochromatin. d) Hyperchromatin. e) Polychromatin.
Figure 2
- Figure 2 shows the main conserved features of eukaryotic introns necessary for correct splicing. Which two bases would you expect to find at the 5’splice site ( X ) in the majority of genes? a) AG. b) CA. c) GA. d) GU. e) UG.
- Figure 2 shows the main conserved features of eukaryotic introns necessary for correct splicing. Which two bases would you expect to find at the 3’splice site ( Y ) in the majority of genes? a) AG. b) CA. c) GA. d) GU. e) UG.
- Figure 2 shows the main conserved features of eukaryotic introns necessary for correct splicing. Apart from the 2’ and 5’ splice sites and the polypyrimidine tract, what is the only other site found in all spliced introns ( Z )? a) The branch site. b) The enhancer site. c) The internal splice site. d) The lariat site. e) The ligation site.
Text F. There are three main components of the cytoskeleton. Microtubules are formed when tubulin dimers polymerise. Microtubules are organized at structures such as the X. Microfilaments are composed from polymerized Y and intermediate filaments consist of a range of different proteins including Z.
- Read text F. This question asks you to replace an underlined letter in text F with a word or phrase chosen from the list below. Which word or phrase would you choose to replace X? a) Centrosome. b) Nucleosome. c) Phragmosome. d) Proteosome. e) Ribosome.
- Read text F. This question asks you to replace an underlined letter in text F with a word or phrase chosen from the list below. Which word or phrase would you choose to replace Y? a) Actin. b) Claudin. c) Kinesin. d) Tubulin. e) Vimentin.
- Read text F. This question asks you to replace an underlined letter in text F with a word or phrase chosen from the list below. Which word or phrase would you choose to replace Z? a) Actin. b) Claudin. c) Kinesin. d) Tubulin. e) Vimentin.
Question 3. Draw and label a figure showing the internal structure of a typical mitochondrion (6 marks).
Question 4. Describe (or sketch) the appearance of the rough endoplasmic reticulum under the electron microscope and give the reason for this appearance (3 marks).
List three functions carried out by the smooth endoplasmic reticulum (3 marks). Function 1
Function 2
Function 3
Question 5.
State four ways in which fluid-phase endocytosis differs from receptor-mediated endocytosis (4 marks). 1 3
How does fluid-phase endocytosis help maintain a constant cell size (2 marks)?
Question 6.
Give three problems in extracellular signal perception that are solved by cell-surface receptors. What features of receptors solve these problems? (6 marks) Problem Solution 1
Question 7.
What is the basic structure of cellulose (2 marks).
Give one way in which hemicelluloses differ from cellulose? (1 mark).
