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CEB601S - CELL BIOLOGY - 1ST OPP -JUNE 2023 |
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nAm I BI A u n IVE RS ITV
OF SCIEn CE Ano TECHn OLOGY
FACULTYOF HEALTH,APPLIEDSCIENCESAND NATURALRESOURCES
SCHOOLOF NATURALAND APPLIEDSCIENCES
DEPARTMENTOF BIOLOGY,CHEMISTRYAND PHYSICS
QUALIFICATION: BACHELOR OF SCIENCE(MAJOR AND MINOR)
QUALIFICATION CODE:07BOSC
LEVEL:6
COURSECODE: CEB601S
COURSENAME: CELLBIOLOGY
SESSION:JUNE 2023
PAPER:THEORY
DURATION: 3 HOURS
MARKS: 100
EXAMINER
FIRSTOPPORTUNITYQUESTION PAPER
DR LAMECH MWAPAGHA
MODERATOR DR JEYA KENNEDY
INSTRUCTIONS
1. Answer ALL the questions.
2. Write clearly and neatly.
3. Number the answers clearly.
4. All written work MUST be done in BLUEor BLACKink.
PERMISSIBLEMATERIAL
Scientific Calculator
THIS QUESTION PAPERCONSISTSOF EIGHT (8) PAGES
{Including this front page)
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SECTIONA: MULTIPLECHOICEQUESTIONS
[20]
• There are 20 multiple choice questions in this section. Each question carries 1 mark.
• Answer ALLquestions by selecting the LETTERwith the correct answer.
1. Which of the following statements about the reactions of glycolysis is correct?
A. In glycolysis glucose-6-phosphate is split into glyceraldehyde-3-phosphate and
dihydroxyacetone phosphate.
B. In glycolysis fructose-6-phosphate is split into glyceraldehyde-3-phosphate and
dihydroxyacetone phosphate.
C. In glycolysis glucose-6-phosphate is isomerized to fructose-1:6-bisphosphate.
D. In glycolysis fructose-1:6-bisphosphate is split into glyceraldehyde-3-phosphate and
dihydroxyacetone phosphate.
2. Which of the following types of molecules are the major structural components of the cell
membrane?
A. Phospholipids and proteins
B. Phospholipids and cellulose
C. Nucleic acids and proteins
D. Proteins and cellulose
3. Cancer is caused by;
A. Uncontrolled meiosis
B. Rupturing of cells
C. Uncontrolled mitosis
D. Loss of immunity of the cells
4. Fat is hydrolysed by the enzyme known as;
A. Lipase
B. Pepsin
C. Trypsin
D. Amylase
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5. Which of the following microscopy techniques, relies on the specimen interfering with the
wavelength of light to produce a high contrast image, without the need for dyes or any
damage to the sample?
A. Conventional bright field light microscopy
B. Phase contrast microscopy
C. Electron microscopy
D. Fluorescence microscopy
6. Acts as the digestive system inside a cell. It helps to break down old or unneeded parts of
the cell, and substances that have been brought into the cell from the outside.
A. Endoplasmic reticulum
B. Ribosome
C. Lysosome
D. Mitochondria
7. The volume enclosed by the plasma membrane of plant cells is often much larger than the
corresponding volume in animal cells. The most reasonable explanation for this
observation is that;
A. Plant cells are capable of having a much higher surface-to-volume ratio than animal
cells.
B. Plant cells have a much more highly convoluted (folded) plasma membrane than
animal cells.
C. Plant cells contain a large vacuole that reduces the volume of the cytoplasm.
D. Plant cells can have lower surface-to-volume ratios than animal cells because plant
cells synthesize their own nutrients.
8. Which of the following deoxyoligonucleotides will hybridize with a DNA containing the sequence
(5')AGACTGGTC(3')?
A. (5')CTCATTGAG(3')
B. (5')GAGTCAACT(3')
C. (5')TCTGACCAG(3')
D. (5')GACCAGTCT(3')
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9. Which of the following statements about the electron transport chain is correct?
A. The electron transport chain is made up of a chain of electron carriers with decreasing electron
affinity.
B. The electron transport chain is made up of a chain of electron carriers with decreasing oxidising
power.
C. The electrons transferred from carrier to carrier in the electron transport chain gain energy.
D. The electron transport chain is made up of a chain of electron carriers with increasing redox
potential.
10. Which of the following statements is true of Na+/K+-adenosine triphosphatases?
A. Their actions maintain a membrane potential with a value often of approximately -60
mV; the interior of the cell being positive with respect to the exterior
B. They use the free energy from the hydrolysis of ATPto transport K+out the cell and Na+
into the cell
C. They are tetramers, consisting of four equally sized polypeptide chains
D. They indirectly control the volume of the cell
11. The chemical equation for photosynthesis;
A. 6C02 + C5H120G--->using sunlight---> 6H20 + 602
B. 6C02 + 602 --->using sunlight---> C5H120G+ 6H20
C. 6C02 + 6H20 --->using sunlight---> C5H120G+ 602
D. 602 + 6H20 --->using sunlight---> C5H120G+ 6C02
12. Photograph which is taken from a microscope is known as;
A. Macrograph
B. Monograph
C. Micrograph
D. Pictograph
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13. Calculate the field of view (0FOV) in µm of a microscope with a field of view index
(FVI) 18 and an objective magnification ofX20.
A. 1900 µm
B. 890 µm
C. 900 µm
D. 90 µm
14. Which of the following statements is true?
A. When signal molecules first bind to receptor tyrosine kinases, the receptors
phosphorylate a number of nearby molecules.
B. In response to some G-protein-mediated signals, a special type of lipid molecule
associated with the plasma membrane is cleaved to form IP3 and calcium.
C. Toxins such as those that cause botulism and cholera interfere with the ability of
activated G proteins to hydrolyze GTP to GDP, resulting in phosphodiesterase activity
in the absence of an appropriate signal molecule.
D. Protein kinase A activation is one possible result of signal molecules binding to G
protein-linked receptors.
15. From the following list select the elements that are metals:
I. Fe, II. S, Ill. Si, IV. Na, V. U, VI. Hg
A. II, 111
B. I, 111I,V, V
C. I, IV, V, VI
D. Ill, IV, V
16. Arrange the following atoms in order of increasing electronegativity: Sb, I, Sn, Te
A. I, Te, Sb, Sn
B. Sb, I, Sn, Te
C. Sn, Sb, Te, I
D. Sn, Te, Sb, I
17. Which two reactions occur during photophosphorylation?
A. ATP is hydrolysed and NADP is reduced.
B. ATP is hydrolysed and NADPH is oxidised.
C. ATP is synthesised and NADP is reduced.
D. ATP is synthesised and NADPH is oxidised.
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18. Which of the following describes cell communication systems?
A. Cell signaling evolved more recently than systems such as the immune system of
vertebrates.
B. Communicating cells are usually close together.
C. Most signal receptors are bound to the outer membrane of the nuclear envelope.
D. In response to a signal, the cell may alter activities by changes in cytosol activity or in
transcription of RNA.
19. The volume enclosed by the plasma membrane of plant cells is often much larger than the
corresponding volume in animal cells. The most reasonable explanation for this
observation is that;
A. Plant cells are capable of having a much higher surface-to-volume ratio than animal
cells.
B. Plant cells have a much more highly convoluted (folded) plasma membrane than
animal cells.
C. Plant cells contain a large vacuole that reduces the volume of the cytoplasm.
D. Plant cells can have lower surface-to-volume ratios than animal cells because plant cells
synthesize their own nutrients.
20. A sample of blood, added to a saline solution with a less negative water potential than
the cell contents, results in a uniform red colour in the solution which is unaffected by
centrifugation. Which one of the following explains this result?
A. Haemoglobin has diffused through the erythrocyte membrane into the solution.
B. Water has entered the erythrocytes by osmosis, causing them to swell and burst and
the haemoglobin is released into the solution.
C. Water has entered erythrocytes by osmosis. As the cells are now less dense than the
solution, they will not sediment on centrifugation.
D. Water has left the cells by osmosis, causing them to shrink and become too small to
sediment on centrifugation.
END OF SECTIONA
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SECTION B
• There are FIVE (5) questions in this section. Answer all Questions.
Question 1
a) Describe the following terminologies as used in microscopy;
I. Photobleaching:
II. Resolution:
111. Phototoxicity:
IV. Fluorescent in situ hybridization (FISH):
b) State FOUR (4) applications of the fluorescence microscope.
c) Briefly, discuss FIVE (5) factors that affect enzyme action.
Question 2
a) The glycolysis pathway is regulated by THREE (3) enzymes namely;
b) Distinguish between carrier proteins and channel proteins.
c) Describe the G-protein coupled receptors in cell signalling.
Question 3
a) Briefly describe the THREE (3) cell signalling stages.
b) Explain FIVE (5) functions of membrane proteins.
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[80)
[18)
(4)
(4)
(10)
(16]
(3)
(4)
(9)
(16]
(6)
(10)
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.
(..
Question 4
[14]
a) Draw the Haworth projection of the monosaccharide below in the a and p forms.
(8)
CHO
I
H-C-OH
I
HO-C-H
I
H-C-OH
I
H-C-OH
I
CH 2 0H
b) Briefly describe how the movement of sodium and potassium ions takes place across the cell
membrane.
(6)
Question 5
[16]
a) Describe the THREE{3) main steps in Polymerase Chain Reaction.
(6)
b) Briefly discuss what happens during each phase of the eukaryotic cell cycle.
(10)
END OF SECTIONB
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PERIODICTABLEOF THE ELEMENTS
18
l
2
H
1.00794 2
13
14
15
He
16 17 4.00260
34
5
6
7
8
9 10
Li Be
B C N 0 F Ne
6.941 9.01218
10.81 12.01l 14.0067 15.9994 18.9984 20.179
11 12
13 14 15 16 17 18
Na Mg
Al Si p s Cl Ar
22.9898 24.305 3
4
5
6
7
8
9
10
11
12 26,9815 28.0855 30.9738 32.06 35.453 39,948
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
K Ca Sc Ti V Cr Mn Fe Co. Ni Cu Zn Ga Ge As Se Br Kr
39.0983 40.08 44.9559 47.88 50.9415 51.996 54.9380 55.847 58.9332 58.69 63.546 65.38 69.72 72.59 74.9216 78.96 79.904 83.8
"O
i:>)
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
OQ
Rb Sr y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
\\0
0....,
85.4678 87.62 88.9059 91.22 92.9064 95.94 (98) 101.07 102.906 106.42 107.868 112.41 114.82 118.69 121.75 127.6 126.9 131.29
\\0
55 56 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
Cs Ba Lu Hf Ta w Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
132.905 137.33 174.967 178.49 180.948 183.85 186.207 190.2 192.22 195.08 196.967 200.59 204.383 207.2 208.908 (209) (210) (222)
87 88 103 104 105 106 107 108 109 110 111 112
114
116
118
Fr Ra Lr Rf Db Sg Bh Hs Mt Uun Uuu Uub
Uuq
(223) 226.02, (260) {261) (262} (263) {264) (265) {268) (269) (272) (269)
Uuh
Uuo
Lantbanides: 57 58 59 60 61 62 63 64 65 66 67 68 69 70
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb
138.906 140.12 140.908 144.24 (145) 150.36 151.96 157.25 158.925 162.50 161.930 167,26 166.934 173.04
Actinides:
89 90 91 92 93 94 95 96 97 98 99 100 101 102
u Ac Th Pa
Np Pu Am Cm Bk Cf Es Fm Md No
227.028 232.038 231.036 238.029 237.048 (244) (243) (247) (247) (251) (252) {257) (258) (259)