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CMB521S - CELL AND MOLECULAR BIOLOGY - 1ST OPP - NOVEMBER 2023 |
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n Am I B I A u n IVE Rs I TY
OF SCIEnCE AnOTECHnOLOGY
Faculty of Health, Natural
Resources and Applied
Sciences
Schoof of Health Sciences
Department of Clinical
Health Sciences
QUALIFICATION : BACHELOR of MEDICAL LABORATORY
QUALIFICATION CODE: 08BMLS
COURSE:CELLAND MOLECULAR BIOLOGY
DATE: NOVEMBER 2023
DURATION: 3 HOURS
13Jackson Kaujeua Street
Private Sag 13388
Windhoek
NAMIBIA
T: +7.6461207 2970
F: +264 61 207 9970
E: dchs@nust.na
W: www.nust.na
LEVEL:5
COURSECODE: CMB521S
SESSION: 1
MARKS: 100
FIRST OPPORTUNITY: EXAMINATION QUESTION PAPER
EXAMINER:
MODERATOR:
Ms Belinda Roselin Tsauses
Ms Edwig Shingenge
INSTRUCTIONS:
1. Answer all questions in the answer book.
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.
PERMISSIBLE MATERIALS:
l. None.
ATTACHEMENTS
l. None.
This paper consists of 5 pages including this front page
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SECTION A: MULTIPLE CHOICE AND TRUE/ FALSE
(20 MARKS)
QUESTION 1: MULTIPLE CHOICE QUESTIONS
[10 MARKS)
Evaluate the statements in each numbered section and select the most appropriate answer or
phrase from the given possibilities. Fill in the appropriate letter next to the number of the
correct statement/phrase in your ANSWER BOOK.
(10]
1.1 Paracrine signaling:
(1)
a) Only affects cells in close proximity.
b) Targets a distant cell through the bloodstream.
c) Occurs when a cell signals itself.
d) Targets a cell connected by gap junctions.
1.2 Internal receptors, also known
a) Nucleus.
b) Cell membrane.
c) Cytoplasm.
d) Golgi apparatus.
as intracellular
or cytoplasmic
receptors,
are found
in the:
(1)
1.3 Cell-surface receptors, also known as transmembrane receptors, are: integral proteins
that bind to external signaling molecules.
(1)
a) Integral proteins.
b) Channel proteins.
c) Cell organelles.
d) Vesicles.
1.4 An example of paracrine signaling is:
(1)
a) A mechanism used by cancer cells for survival.
b) Localized inflammation at infection site.
c) Cancer metastasis.
d) None of the above.
1.5 This process, in which homologous chromosomes trade parts in meiosis is called:
(1)
a) Swapping.
b) Crossing over.
c) DNA replication.
d) None of the above.
1.6 The process of translation takes place in the:
(1)
a) Ribosomes.
b) Lysosomes.
c) Nucleus.
d) Cytoplasm.
Cell and Molecular Biology (CMB521S)
1st Opportunity November 2023 2
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1.7 The function oft-RNA is to:
(1)
a) Encode amino acid sequence of a polypeptide.
b) Form complexes that are used in RNA processing in eukaryotes.
c) Bring amino acids to ribosomes during translation.
d) All of the above.
1.8 In RNA, pyrimidines are nitrogenous bases that includes:
(1)
a) Adenine and Guanine.
b) Cytosine and Uracil.
c) Cytosine and Thymine.
d) Cytosine and Guanine.
1.9 In terms of the genetic code, the start codon is:
(1)
a) AUG.
b) UAA.
c) UAG.
d) UGA.
1.10 In mitosis, the mitotic spindle is responsible for:
(1)
a) Dividing the cell into two.
b) Carrying out cytoplasmic division.
c) DNA replication.
d) Nuclear division.
QUESTION 2: TRUE/FALSE QUESTIONS
[10 MARKS]
Evaluate the statements and select whether the statement is true or false. Write the word 'True'
or 'False' next to the corresponding number in your ANSWER BOOK.
[10]
2.1 Anton van Leeuwenhoek was the first person to record the appearance of human cells,
such as red blood cells, spermatozoa, bacteria, yeasts, diatoms.
(1)
2.2 Schwann and Schleiden published the cell theory.
(1)
2.3 Eukaryotes do not have centrioles.
(1)
2.4 An offspring inherits mitochondria, and as a result mitochondrial DNA from their mother. (1)
2.5 Ribosomes are manufactured in the nucleolus.
(1)
2.6 Centrioles play a role in organizing microtubules that serve as the cell's skeletal system. (1)
2.7 Ribosomes are the site of DNA replication in the cell.
(1)
2.8 The nucleus is the site that is responsible for the cells metabolic activities.
(1)
2.9 The main difference between the different categories of signalling is the distance that the
signal travels to reach the target cell.
(1)
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2.10 Meiosis is a process where a single cell divides once to produce four cells containing
half the original amount of genetic information.
(1)
SECTIONB:SHORTANSWER QUESTIONS
Please answer ALL of the questions in this section.
[35 MARKS)
QUESTION 3:
[16 MARKS]
3.1 Name and describe the role of three (3) main cell organelles in vesicular transport. (6)
3.2 Explain the four (4) steps involved in the retrieval pathway of vesicular transport. (4)
3.3 Briefly highlight the significance of endocytosis relating to its purpose in
maintaining optimum biochemical functions. Give relevant examples to support your
answers.
(6)
QUESTION 4:
[19 MARKS]
4.1 Sketch a neatly labelled diagram depicting the fluid mosaic model of the cell membrane
illustrating the following components:
(a) Extracellular fluid
(1)
(b) Intracellular fluid
(1)
(c) Phospholipid bilayer
(1)
(d) Hydrophobic tail
(1)
(e) Hydrophilic head
(1)
4.2 The diagrams below depict the concept of the "membrane potential". For each
diagram, demonstrate your understanding of this concept in your own words. Two
(2) marks are allocated per diagram.
(6)
(a)
(b)
(c)
0 0 e IlLf!Jill
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cytop©i2 ©
Cell and Molecular Biology {CMB521S)
1st Opportunity November 2023 4
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----------------~----------------------------------··
,
4.3 Tabulate the difference between the following classes of functional membrane proteins
based on the proteins and the function.
(a) Transporters
(2)
(b) Iron channels
(2)
(c) Anchors
(2)
(d) Receptors
(2)
'SECTION C: LONG ANSWER QUESTIONS
.. {45 MARKS]
Please answer ALL of the questions in this section. Give your answers in point form.
QUESTION 5:
{15 MARKS]
Discuss the Watson & Crick Model of DNA in detail and support your discussion with
relevant examples.
(15)
QUESTION 6:
[15 MARKS]
Describe the action of enzymes that participate in the eukaryotic DNA replication process.
(15)
QUESTION 7:
[15 MARKS]
Explain the mechanism of proofreading and substantiate its importance in the DNA
replication process.
(15)
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END OF PAPER
Cell and Molecular Biology (CMB521S)
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