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GEN602S - GENETICS - 2ND OPP - JANUARY 2025 |
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nAm I BIA UnlVERSITY
0 F SCIEnCE Ano TECHn OLOGY
FacultyofHealthN, atural
ResourceasndApplied
Sciences
Schoolof Natural and Applied
Sciences
Departmentof Biology,
Chemistryand Physics
13Jackson Kaujeua Street
Private Bag 13388
Windhoek
NAMIBIA
T: +264 61207 2012
F: +264 61207 9012
E: dbcp@nust.na
W: www.nust.na
QUALi FICATION: BACHELOR OF SCIENCE
QUALIFICATION CODE: 07BOSC
LEVEL: 6
COURSE:GENETICS
DATE: JANUARY 2025
DURATION: 3 HOURS
COURSECODE: GEN602S
SESSION: 1
MARKS: 100
SECOND OPPORTUNITY/ SUPPLEMENTARY: QUESTION PAPER
EXAMINER:
MODERATOR:
Prof Edosa Omoregie
Dr Jeya Kennedy
INSTRUCTIONS
1. Answer all questions on the separate answer sheet.
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:
1. Non-Programmable Calculator
ATTACHMENTS
None
This paper consists of 6 pages, including this front page
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SECTION A: MULTIPLE CHOICE
[20 MARKS)
QUESTION 1: MULTIPLE CHOICE QUESTIONS
(20 MARKS]
Evaluate the statements in each numbered section and select the most appropriate answer
from the given possibilities. Fill in the appropriate letter next to the number of the correct
statement/phrase on your ANSWERSHEET.
(20]
1.1. Which of the following statements best describes the term "homologous chromosomes"?
a) Chromosomes that code for the same traits but are identical in form
b) Chromosomes inherited from the same parent
c) Chromosomes with the same gene sequence but different alleles
d) Chromosomes that have undergone mutation
e) Chromosomes that are involved in DNA replication
1.2. Which phase of the cell cycle is most critical for checking DNA integrity
division?
a) Gl phase
b) S phase
c) G2 phase
d) Prophase
e) Metaphase
before cell
1.3. Which of the following is an example of codominance?
a) Blood type AB in humans
b) Pink flowers from red and white parent plants
c) Sickle cell trait
d) Freckles in humans
e) Pea plant height
1.4. What is the main role of helicase in DNA replication?
a) Proofreading the newly synthesized DNA
b) Joining Okazaki fragments
c) Unwinding the double helix
d) Synthesizing RNA primers
e) Sealing the sugar-phosphate backbone
1.5. What is the function of Okazaki fragments in DNA replication?
a) They are synthesized in the leading strand
b) They join the two daughter DNA molecules
c) They form the continuous strand of DNA
d) They are short sequences synthesized on the lagging strand
e) They prevent mutations from occurring
1.6. Which type of chromosomal mutation involves the complete loss of a chromosome?
a) Duplication
b) Inversion
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c) Translocation
d) Deletion
e) Nondisjunction
1.7. Inversions and translocations differ in that:
a) Inversions involve gene loss
b) Translocations do not alter genetic content
c) Inversions reverse the direction of a segment within the same chromosome
d) Translocations happen only between non-homologous chromosomes
e) Inversions always result in a lethal phenotype
1.8. What is the purpose of gene splicing in eukaryotic cells?
a) To remove exons and join intrans
b) To produce different proteins from the same gene
c) To prevent the transcription of defective genes
d) To control the initiation of DNA replication
e) To synthesize ribosomal RNA
1.9. Post-translational modification of proteins occurs to:
a) Enhance mRNA stability
b) Facilitate transcription factor binding
c) Regulate protein activity and function
d) Modify the DNA sequence of genes
e) Prevent mRNA degradation
1.10 What is the primary purpose of homologous recombination?
a) To correct errors in DNA replication
b) To exchange genetic material between homologous chromosomes
c) To prevent chromosomal translocations
d) To ensure accurate DNA replication
e) To repair damaged RNA molecules
1.11. In which phase of meiosis does crossing over occur?
a) Prophase I
b) Anaphase II
c) Metaphase I
d) Telophase I
e) Prophase II
1.12. Which of the following blood genotypes belongs to an individual who is regarded as a
universal blood recipient?
a) IAIA
b) 1A10
C) IAIB
d) 1o1o
e) None
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1.13. Which of the following autosomal chromosome conditions is for an individual suffering
from Down Syndrome?
a) Trisomy 18
b) Trisomy 21
c) X monosomy
d) Trisomy 15
e) None of these
1.14. Which of the following is an assumption for Hardy-Weinberg equilibrium?
a) no epistasis
b) no dominance
c) no crossing-over
d) no mutation
e) spontaneous mutation
1.15. Which of the following chromosome number is a pentasomy?
a) 2n - 2
b 2n + 2
c) 2n -1
d) 2n + 3
e) 2n + 1
1.16. A human with Patau's syndrome would represent which of the following chromosomal
conditions?
a) Diploid condition
b) Euploid condition
c) Aneuploid condition
d) Haploid condition
e) Triploid condition
1.17. What is the significance of gene recombination in evolution?
a) It leads to genetic uniformity within a population
b) It increases genetic diversity and evolutionary potential
c) It eliminates harmful mutations from the genome
d) It regulates the expression of genes in response to environmental
e) It causes genetic disorders by introducing mutations
changes
1.18. Which of the following describes gene flow?
a) The transfer of alleles from one population to another
b) The random loss of alleles due to small population size
c) The non-random mating of individuals within a population
d) The formation of new alleles through mutation
e) The gradual elimination of deleterious alleles
1.19. What is a significant ethical concern associated with the cloning of humans?
a) The high cost of cloning procedures
b) The inability to replicate personality traits through cloning
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c) The question of whether a cloned human possesses the same rights as a naturally-born
human
d) The technical difficulty of isolating the correct gene for cloning
e) The inability to control the size and shape of cloned organs
1.20. Which of the following is NOT a potential application of gene therapy as discussed in
genetic engineering?
a) Treating inherited genetic disorders by inserting functional copies of genes
b) Enhancing human physical traits like strength and intelligence
c) Introducing new genes to fight diseases such as cancer
d) Replacing defective genes responsible for causing disease
e) Modifying viruses to serve as vectors to deliver therapeutic genes into cells
SECTION B: ESSAY QUESTIONS
Please answer ANY FOURof the questions in this section.
[80 MARKS)
QUESTION 2
2.1. In tabular form, highlight the main differences between genetic mutation and genetic
variations.
(5)
2.2. Briefly differentiate gene mutation from chromosomal mutation.
(5)
2.3. Compare and contrast mitosis and meiosis, focusing on their roles in reproduction and
inheritance.
(10)
QUESTION 3
3.1. In a tabular form, briefly differentiate the main differences between nucleosome and
chromatid.
(5)
3.2. Describe the synthesis of new DNA and explain the roles of the various enzymes involved
in synthesising new DNA strands from the parent DNA strand.
(10)
3.3. Discuss the significance of proofreading and DNA repair mechanisms in maintaining
genetic fidelity and preventing diseases.
(5)
QUESTION 4
4.1. List the three main functional gene products that control structure and function in
organisms.
(3)
4.2. With schematic diagrams, briefly explain the process of gene expression in eukaryotes
and the role of the enzymes involved in the process.
(12)
4.3. Explain the process of non-replicative transposition and how it differs from replicative
transposition. Use illustrations to show the differences.
(5)
QUESTION 5
Discussthe effects of genetic drift, gene flow, and mutation on population allele frequencies.
Use relevant examples and illustrations to explain how these mechanisms influence
evolutionary change.
(20)
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QUESTION 6
Explain the process of creating genetically modified organisms (GMOs), from identifying a
gene of interest to expressing that gene in the target organism. Discuss the benefits and
potential risks associated with GMOs in agriculture and medicine.
(20)
END OF QUESTION PAPER
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