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CMB521S - CELL MOLECULAR BIOLOGY - 1ST OPP - NOV 2022 |
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nAm I BIA un IVERSITY
OF SCIEnCE Ano TECHnOLOGY
Faculty of Health, Applied Sciences and Natural Resources
Department of Health Sciences
QUALIFICATION: BACHELOROF MEDICAL LABORATORYSCIENCES
QUALIFICATION CODE: 08BMLS
LEVEL: 5
COURSE: CELLAND MOLECULARBIOLOGY
COURSE CODE: CMB521S
DATE: NOVEMBER 2022
SESSION: THEORY
DURATION: 3 HOURS
MARKS: 100
EXAMINER(S)
MODERATOR:
FIRST OPPORTUNITY EXAMINATION QUESTION PAPER
Ms Roselin Tsauses
Ms Vanessa Tjijenda
INSTRUCTIONS
1. Answer all questions.
2. Please write neatly and legibly.
3. Do not use the left side margin of the exam paper. This must be allowed for the
examiner.
4. No books, notes and other additional aids are allowed.
5. Mark all answers clearly with their respective question numbers.
Permissable material
Non programmable calculator is allowed.
THIS EXAMINATION PAPER CONSISTS OF 10 PAGES (Excluding this front page)
Page 1 of 11
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1.2 Page 2 |
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Section A (20 marks)
Question 1
1.
Evaluate the statements in each numbered section and choose the
correct answer. Write the letter of the correct answer next to the
corresponding number. (One (1) mark is allocated for each correct
answer. There is only one (1) correct answer for each question.)
[20]
1.1 Which of the following cell organelles is absent in animal cells and
present in a plant cell?
(1)
(a) Cell wall
(b) Cytoplasm
(c) Vacuoles
(d) Mitochondria
1.2 Which of the following statements is true about the cell wall?
(1)
(a) The cell wall is mainly composed of lipid.
(b) The cell wall is mainly composed of starch.
(c) The cell wall is mainly composed of protein.
(d) The cell wall is mainly composed of cellulose.
1.3 Which of the following statements is true about cell theory?
(1)
(a) The Cell theory does not apply to fungi.
(b) The Cell theory does not apply to virus.
(c) The Cell theory does not apply to algae.
(d) The Cell theory does not apply to microbes.
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1.3 Page 3 |
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1.4.
is a jellylike substance found floating inside the
plasma membrane.
(1)
(a) Cell sap
(b) Cytoplasm
(c) Karyoplasm
(d) Mitochondria
1.5. Which of the following cell organelles is called the powerhouse of the
cell?
(1)
(a) Nucleus
(b) Lysosomes
(c) Chloroplast
(d) Mitochondria
1.6
is the study of the cell, its types, structure, functions
and its organelles.
(1)
(a) Biology
(b) Cell Biology
(c) Microbiology
(d) Biotechnology
1.7 Which of the following cell organelles is absent in prokaryotic cells?
(1)
(a) Nucleus
(b) Lysosome
(c) Endoplasmic Reticulum
(d) All of the above
1.8 Which of the following cell organelles is involved in the storage of
food, and other nutrients, required for a cell to survive?
(1)
(a) Vacuoles
(b) Lysosome
(c) Mitochondria
(d) Cell membrane
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1.4 Page 4 |
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1.9 ------
is involved in the synthesis of phospholipids.
(1)
) (a) Mitochondria
, (b) Cytoplasm
.!
i
· ·.(c)'Endoplasmic Reticulum
(d) Smooth Endoplasmic Reticulum
1.10 Which of the following statements is true about chromosomes?
(1)
(a) It is present within the nucleus.
(b) It carries genes and helps in inheritance.
(c) It is composed of DNA in the form of Chromatin and protein.
(d) All of the above.
1.11 Which of the following statements is true about the Golgi bodies?
(1)
(a) It is a sac-like organelle.
· (b) It is located near the nucleus.
(c) It helps in transporting the particles throughout the cell.
(d) All of the above.
1.12. Which of the following statements is true about the nucleus?
(1)
(a) It is absent in prokaryotes.
(b) It is called the brain of the cell.
(c) It contains DNA and other genetic materials.
(d) All of the above.
1.13 Which among the following is studded with millions of membrane
bound ribosomes.
(1)
(a) Rough endoplasmic reticulum
(b) Smooth endoplasmic reticulum
(t) Symplast
(d) Nucleus
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1.14 Ribosomes are sites for ------
(1)
(a) protein synthesis
(b) photosynthesis
(c) fat synthesis
(d) respiration
1.15 Ribosomes are made up of
(1)
(a) DNA and RNA
(b) RNA and Protein
(c) DNA and Protein
(d) RNA and Amino acids
1.16 The full form of DNA is
(1)
(a) deoxyriboneutral acid
(b) delta nucleic acid
(c) deoxyribonucleic acid
{d) dyoxyenucleic acid
1.17 The lipid bilayer is
(1)
(a) hydrophilic
(b) hydrophobic
{c) hydrophilic and hydrophobic
(d) None of the above.
1.18 Which molecules make the membrane a rigid structure?
(1)
(a) Cholesterol molecules
{b) Proteins
{c) Phospholipids
(d) All of the above
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1.6 Page 6 |
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1.19 The functional unit of life is called
(1)
(a) cell
(b) egg
(c) nucleus
(d) none of the above
1.20 The cell is discovered by
(1)
(a) Robert Brown
(b) Robert Hooke
(c) John Mendal
(d) Charles Darwin
Section B (30 marks)
Question 2
[16]
2.1 Describe the fluid mosaic membrane.
(7)
2.2 Differentiate between simple and facilitated diffusion.
(2)
2.3 An artificial cell consisting of an aqueous solution enclosed in a
selectively permeable membrane is immersed in a beaker containing a
different solution. The membrane is permeable to water and to the
simple sugars glucose and fructose, but impermeable to the disaccharide
sucrose.
,·l
•
0.02 M gluccrse
Environment
0.01 M sucrose
0.01 M glucose
0.o1, M fructose
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2.3.1 Copy the above illustration and draw solid arrows to indicate the net
movement of solutes into and/ or out of the cell.
(2)
2.3.2 Draw a dashed arrow to show the net osmotic movement of water,
if any.
(1)
2.3.3 Is the solution outside the cell isotonic, hypotonic, or hypertonic?
(1)
2.3.4 Will the artificial cell become more flaccid, more turgid, or stay the
same?
(1)
2.3.5 Eventually, will the two solutions have the same or different solute
concentrations? Motivate your answer.
{2)
Question 3
[14]
3.1 What do you understand by the term vesicular transport?
(2)
3.2 Compare exocytosis and endocytosis in vesicular transport with reference
to the following:
3.2.1 Definition
(2)
3.2.2 Function
(4)
3.2.3 Types
(4)
3.2.4 Examples
(2)
Present your answers in a table.
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1.8 Page 8 |
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Section C (26 marks)
Question 4
[13]
4.1 Study the diagrams below and indicate which of the four (4) categories of
cell communication is depicted by each diagram. Give a brief description
of each category.
4.1.1
(2)
4.1.2
(.:
\\ '•'<,•_if_..:=.:__...-..:.__:~
Signaling cell
Target cell
(2)
4.1.3
-~.
\\
'-:.~-~·
.
V,
'.
•
Signaling eel!
Target cell
(2)
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1.9 Page 9 |
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4.1.4
(2)
4.2 Discuss the implications of dysfunctional cell-to-cell adhesion in cancer
metastasis. Give relevant examples as far as possible.
(5)
Question 5
5.1 Highlight the significance of the cell cycle control system.
5.2 Consider the following diagram that represents a DNA replication fork.
[13]
(8)
3'
3'
5'
5.2.1 Which strand will be produced continuously?
(1)
5.2.2 What are the fragments called that are produced discontinuously?
(1)
5.2.3 What is the name of the enzyme that adds nucleotides to the daughter
strands?
(1)
5.2.4 What does 5' and 3' mean?
(2)
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Section D (24 marks)
Question 6
6.1 Draw a cell with relevant organelles and clearly indicate the site of
transcription and translation on the diagram. Label your drawing.
6.2 What are the three (3) major steps involved in RNA processing?
Give your answer in the correct order.
6.3 Tabulate the difference between transcription and translation on the
following basis:
6.3.1 Enzymes
6.3.2 Initiation
6.3.3 Elongation
[13]
(4)
(3)
(6)
Question 7
7.1 Describe the Watson and Crick model of DNA.
7.2 If the following DNA strands are used as a template for transcription,
which RNA strand will be produced? Write your answer next to the
corresponding number.
7.2.1 3' TCAACCGTTCAGTGA5'
7.2.2 3'- TACCGAGATGTATCAACT-5'
7.3 List the stop codons?
[11]
(5)
(1)
(1)
(3)
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7.4 Using the codon chart, determine the sequence of amino acids that are
produced when the sequence of RNA shown below is translated?
{1)
5' UCU UGU CGA 3'
Second letter
UuUuUc }Phe
. UUA }Leu
UUG
ucu}.UAU}Tyr UGU}cys u
UCC Ser UAC
UGC
C
UCA , UAA Stop UGA Stop A
UCG " UAG Stop UGG_ Trp G
...
0.,
t:
u.e...n:..:
cuu} CUC
CCU} ccc,
CCAAUC} H.ts
CUA Leu CCA Pro.
CUG
CCG
g~}Gtn
AUU}ACU.}. AUC lie ACC
AAAAUC}Asn
AUA
AUG
Met
ACA
ACG
Thr
~}Lys
CCGGC UArg}·uC
CGA
A
CGG.
G
AGU }ser u
AGC
C
AGA }Arg A
AGG.
G
..
0.,
t:
...9:!
"0
:.c
I-
GUU}GCU} GGU} GAU}Asp·
' ·u
GUC Val GCC Ata GAC
. GGC Gly C
GUA
L~]G~G
GCA
GCG
GGAAAG} Glu
GGA
GGG
A
G
Good luck!
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