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GEN602S - GENETICS - 2ND OPP - JAN 2023 |
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n AmI BI A u n IVER s ITY
OF SCIEnCE AnDTECHnOLOGY
FACULTY OF HEALTH, NATURAL RESOURCES AND APPLIED SCIENCES
DEPARTMENT OF NATURAL AND APPLIED SCIENCES
QUALIFICATION: BACHELOROF SCIENCE
QUALIFICATION CODE: 07BOSC
COURSE CODE: GEN602S
SESSION: JANUARY2023
DURATION: 3 HOURS
LEVEL: 6
COURSE NAME: GENETICS
PAPER: THEORY
MARKS: 100
SUPPLEMENTARY/ SECOND OPPORTUNITY EXAMINATION PAPER
EXAMINER (S):
Dr. Edosa Omoregie
MODERATOR:
Dr Jeya Kennedy
INSTRUCTIONS
1. Answer all questions in Sections A and B
2. You may use a calculator
3. Write clearly and neatly
4. Number your answers correctly
5. Draw diagrams wherever necessary
PERMISSIBLE MATERIALS
Calculator
THIS QUESTION PAPER CONSISTS OF 4 PAGES
(Including this front page)
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SECTION A (MULTIPLE CHOICE QUESTIONS, 2 MARKS FOR EACH QUESTION)
[30]
1. When a cell begins to prepare for cell division, DNA synthesis occurs during which of the
following phases?
a) Gl phase
b) S phase
c) G2 phase
d) GOphase
2. Mitotic cell division results in two cells that have:
a) n chromosomes that are genetically identical
b) n chromosomes that are genetically different
c) 2n chromosomes that are genetically identical
d) 2n chromosomes that are genetically different
3. Haemophilia is a sex-linked recessive trait in humans. If a father is a carrier, and their son
is haemophiliac, but the mother is normal, her genotype must be?
a) xhxh
b) xHxh
c) XHXH
d) All of the above
4. Genetic traits of seeds are noted as follows:
L = long, I= short, W = wrinkled, w = smooth, Y = yellow, y = white, R = ribbed, r = grooved.
Which of the following is the genotype for a short, wrinkled, yellow and grooved seed?
a) IIWwyyrr
b) LLWWyYRr
c) LIWwYYRr
d) IIWwYYrr
5. Which of the following is an autosomal recessive trait?
a) Duchenne muscular dystrophy
b) Lesch-Nyhan syndrome
c) Marfan syndrome
d) Cystic Fibrosis
6. Which of the following sequences will a strand of DNA with the sequence of base AACTTG
have a complimentary strand?
a) CCAGGT
b) AACTTG
c) TTCAAG
d) TTGAAC
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7. Which of the strand grows continuously towards the replication fork during the process of
DNA replication?
a) Lagging strand
b) RNA strand
c) Leading strand
d) Replicating strand
8. A human with Turner's syndrome would represent which of the following chromosomal
condition?
a) Diploid condition
b) Euploid condition
c) Aneuploid condition
d) Haploid condition
9. In the genetic code, the number of nucleotides in a single codon is?
a) 2 nucleotides
b) 3 nucleotides
c) 4 nucleotides
d) 6 nucleotides
10. During the process of gene recombination, which of the following enzymes represses the
action of transposase?
a) Ligase
b) Polymerase
c) Helicases
d) Resolvase
11. Which of the following will not occur during post-transcriptional
eukaryotes?
a) The splicing of intrans
b) Addition of a poly-A at the 3' end
c) Removal of intrans
d) Addition of a 7-methyl guanosine cap at the 5' end
processing of RNA in
12. During the process of splicing in gene expression, the removal of intrans from RNA strands
is by which group of enzymes:
a) Primosomes
b) Resolvases
c) Transposase
d) Spliceosomes
13. What complementary DNA strand is the following
5' AUCGACUACGAUCGC3'
a) 5' ATCGACTACGATCGC3'
b) 5' ACCGACTACGAACGC3'
c) 5' AACGACCACGATCGC3'
d) 5'ATCGACCACGATCGC3'
RNA sequence transcribed
from
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14. In which section of DNA below is there a mutation?
I
Se-!:liD/11 51-ctl,)n 7 I S.ectlon 3 I S,,ct:on ,1
I
I
I I I I II t I II I ( I
GAT1ACT1CGT
TGT
WfJRE
I
I
I I ( I I II I ( II
GA T I A C TI CA T I
AFiER
III
TGT
a) Section 1
b) Section 2
c) Section 3
d) Section 4
15. Which of the following factors alter allele frequencies that bring about the most
evolutionary change?
a) Indiscriminating intraspecific mating
b) Inbreeding
c) DNA replication
d) Genetic drift
SECTION B
[70]
16. a). Briefly differentiate gene mutation from chromosomal mutation.
(4)
b). Describe the structure of the messenger RNA.
(11}
17. With the aid of suitable diagram, briefly describe the process of mitotic division in a
eukaryotic cell with emphasis on the changes taking place on the chromosome?
(10}
18. a). With the use of suitable diagrams, discuss the process of gene deletion, duplication,
inversion and translocation in chromosomal mutations.
(8)
b). With reference to chromosomal mutation, number of chromosomes and phenotypic
expression, discuss Fragile X Syndrome genetic disorder.
(7)
19. Using suitable molecular diagrams discuss the structure of the DNA double helix, including
its subunits and the way in which they are bonded together indicating the antiparallel
arrangements of the polynucleotide strands.
(15}
20. With the use of appropriate diagram, discuss the role of transposons, transposase and
resolvases in gene recombination. Why are transposons referred to as important genetic
materials?
(15}
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