 |
CEB601S - CELL BIOLOGY - 1ST OPP - JUNE 2022 |
|
|
1 Page 1 |
▲back to top |
NAMIBIA UNIVERSITY
OF SCIENCE AND TECHNOLOGY
FACULTY OF HEALTH, APPLIED SCIENCES AND NATURAL RESOURCES
DEPARTMENT OF NATURAL AND APPLIED SCIENCES
QUALIFICATION: BACHELOR OF SCIENCE (MAJOR AND MINOR)
QUALIFICATION CODE: 07BOSC
LEVEL: 6
COURSE CODE: CEB601S
COURSE NAME: CELL BIOLOGY
SESSION: JUNE 2022
PAPER: THEORY
DURATION: 3 HOURS
MARKS: 100
EXAMINER
FIRST OPPORTUNITY QUESTION PAPER
DR LAMECH MWAPAGHA
MODERATOR | DR JEYA KENNEDY
INSTRUCTIONS
Answer ALL the questions.
Write clearly and neatly.
Number the answers clearly.
All written work MUST be done in BLUE or BLACK ink.
PERMISSIBLE MATERIAL
Scientific Calculator
THIS QUESTION PAPER CONSISTS OF NINE (9) PAGES
(Including this front page)
Page 1 of9
|
|
2 Page 2 |
▲back to top |
SECTION A: MULTIPLE CHOICE QUESTIONS
[20]
e There are 20 multiple choice questions in this section. Each question carries 1 mark.
e Answer ALL questions by selecting the LETTER with the correct answer.
1. Which of the following is a function of the Golgi apparatus?
A. To aid endocytosis
B. To make proteins from amino acids
C. To synthesize ATP
D . To make secretory products
2. Which type of microscope uses electrons to provide a three-dimensional view of the surface of the
object?
A. Light microscope
B. Transmission electron microscope
C. Scanning electron microscope
D . Scanning-probe microscope
3. Amino acids are
A. building blocks of lipids
B. building blocks of proteins
C. building blocks of carbohydrates
D . building blocks of nucleic acids
4. Apoptosis is classified as;
A. Programmed cell death
B. Non-programmed cell death
C. Accidental cell death
D. Mitotic cell death
Page 2 of 9
|
|
3 Page 3 |
▲back to top |
. In which phase of the cell cycle is DNA replicated?
A. G1 phase
B. S phase
CG, G2 phase
D. M phase
. Which of the following is NOT evidence of the endosymbiotic theory?
A. Mitochondria are similar to bacteria in size and structure
B. Mitochondria and chloroplasts have a double membrane: the outer membrane may be derived
from the engulfing vesicle, and the inner one may be derived from the plasma membrane of
the original prokaryote
Mitochondria and chloroplasts contain a limited amount of their own DNA and divide by
splitting
The cristae in mitochondria resemble those found in bacteria
. One molecule of acetyl-coenzyme A yields what energy rich molecules when metabolized via the
citric acid cycle?
A. 6 NADH + 2 FADH2 + 2 GTP
B. 3 NADH + 1 FADH2+ 1 GTP
CG 4 NADH + 1FADH2 + 1 GTP
D. 3 NADH + 2 FADH2 + 1 GTP
. Which term describes centrioles beginning to move apart in animal cells?
A. Telophase
B . Anaphase
C. Prometaphase
D . Prophase
Page 3 of 9
|
|
4 Page 4 |
▲back to top |
9. The ribonucleotide polymer (5')GTGATCAAGC(3') could only form a double-stranded structure
with;
A (5')CACTAGTTCG(3')
B (5')CACUAGUUCG(3')
C (5')CACUTTCGCCC(3')
D (5')GCTTGATCAC(3’)
10. Which of the following statements about the generation of ATP in the electron transport chain is
correct?
A. The generation of ATP from ADP coupled to electron transfer occurs by substrate level
phosphorylation as in glycolysis
ATP synthase generation of ATP involves a rotating structure inside the inner mitochondrial
membrane
Electron transport generates a proton gradient across the outer mitochondrial membrane
ATP synthase generation of ATP involves a rotating structure outside the inner mitochondrial
membrane
11. Cells in culture will absorb amino acids from the surrounding culture medium. If radioactively
labelled glycine is provided in the culture medium, in which organelle will radioactivity be found
first?
A. ribosomes
B nucleus
C lysosomes
D . Golgi apparatus
12. The movement of water molecules from an area of high concentration to an area of low
concentration through a semipermeable membrane is known as;
A. Active Transport
B Diffusion
C. Phagocytosis
D . Osmosis
Page 4 of 9
|
|
5 Page 5 |
▲back to top |
13. Which of the following statements about the TCA cycle is correct?
A. Oxygen is used to oxidise the acetyl group carbons of acetyl-CoA in the TCA cycle
B Oxygen is not used in the TCA cycle, so the cycle can occur in anaerobic conditions
C. The TCA cycle produces the water that is formed during the complete oxidation of glucose
D . Three molecules of NADH and one molecule of FADH2 are produced in one turn of the TCA
cycle
14. 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
15. Which of the following apply to intercellular junctions?
A. The three major adhesive junctions of animal cells are adherens junctions,
desmosomes and hemidesmosomes
The junctional complexes of gastrointestinal enterocytes ensure that nutrients are only
absorbed through the spaces between the cells, which prevents them absorbing
potentially harmful substances
Desmosomes and hemidesmosomes connect epithelial cells to their basement
membrane and adjacent cells respectively
Gap junctions and plasmodesmata are homologous structures
16. Holes in plant leaves that allow carbon dioxide to enter and oxygen to leave.
Stomata
Roots
Chlorophyll
Chloroplast
Page 5 of9
|
|
6 Page 6 |
▲back to top |
17. 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
. They use the free energy from the hydrolysis of ATP to transport K+ out the cell and Na+ into the
cell
They are tetramers, consisting of four equally sized polypeptide chains
. They indirectly control the volume of the cell
18. Which statement correctly outlines some of the main events in photosynthesis?
A. A 5C carbohydrate accepts carbon dioxide and is then reduced by NADPH derived
from photophosphorylation.
A 3C carbohydrate is regenerated and reduced by hydrogen molecules derived from
photophosphorylation.
Photolysis uses light to produce reduced NADP and oxygen which are used to reduce
a 3C carbohydrate.
Photolysis produces NADPH and ATP which are used to reduce a 5C carbohydrate.
19. What is the overall net equation of the citric acid cycle?
A. Acetyl-coA + 3NAD* + FAD + ADP + Pi + 2H20 = CoA + 2CO2 + 3NADH + FADH2 + ATP + 2H*
B. Glucose + 2NAD* + 2ADP + 2Pi = 2Pyruvate + 2ATP + 2NADH + 2H20 + 2H*
C. CoA + NAD* + 3FAD + ADP + Pi + 2H20 = Acetyl-coA + 2CO2 + NADH + 3FADH2 + ATP + 2H*
D. Glucose + 2H20 + 10NAD* + 2FAD + 4ADP + 4Pi + = 6CO2 + 1ONADH + 2FADH2 + 4ATP + 10H*
20. Which reaction is catalysed by the enzyme RuBisCO?
A. Carboxylation of ribulose bisphosphate (RuBP)
B . Conversion of triose phosphate (TP) to ribulose phosphate (RuP)
G Oxidation of glycerate-3-phosphate (GP)
D . Reduction of glycerate-3-phosphate (GP)
END OF SECTIONA
Page 6 of 9
|
|
7 Page 7 |
▲back to top |
SECTION B
[80]
e There are FIVE (5) questions in this section. Answer all Questions.
Question 1
[12]
a) Describe the THREE (3) main steps in Polymerase Chain Reaction.
(3)
b) Explain the role of each of the following enzymes involved in DNA replication
(4)
c) As aresearch scientist you have been tasked to generate Ideal PCR primers for gene amplification.
Briefly state FIVE (5) factors you would consider when designing primers.
(5)
Question 2
[17]
a) Briefly describe the structure and functions of the extracellular matrix.
(3)
b) State FOUR (4) applications of the confocal microscope.
(4)
c) Fluorescence in situ hybridization (FISH) is a laboratory technique for detecting and locating a
specific DNA sequence on a chromosome. The technique relies on exposing chromosomes to a
small DNA sequence called a probe that has a fluorescent molecule attached to it. State TEN (10)
applications of FISH.
(10)
Question 3
[18]
a) Briefly describe the functions of the following RNA’s:
(10)
|. Messenger RNA (mRNA):
Il. Ribosomal RNA (rRNA):
lll. Transfer RNA (tRNA):
IV. Small nuclear RNA (snRNA):
V. microRNA (miRNA):
Page 7 of 9
|
|
8 Page 8 |
▲back to top |
b) Describe Protein scaffolds.
c) Names the phases of mitosis shown in the images below:
(4)
ee
I
(en ag
IV
Question 4
[17]
a) Briefly describe the following chemical signals;
(5)
|. | Pheromones Signals:
Il. | Neuroendocrine Signals:
Ill. | Autocrine Signals:
IV. Neural Signals:
V.
Paracrine Signals:
b) What is the fate of absorbed glucose by tissues in Eukaryotes?
(6)
Page 8 of 9
|
|
9 Page 9 |
▲back to top |
c) Briefly describe how the movement of sodium and potassium ions takes place across the cell
membrane.
(6)
Question 5
[16]
a) Distinguish between carrier proteins and channel proteins.
(2)
b) Briefly explain the Electron Transport Chain/Oxidative Phosphorylation process.
(8)
c) Draw the Haworth projection of the monosaccharide below in the a and B forms.
(6)
CHO
HHOot —¢H —H
im—e-—=on
H —<— oF
CH,OH
END OF SECTION B
Page 9 of 9