GEN602S- GENETICS - JAN 2020


GEN602S- GENETICS - JAN 2020



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o
NAMIBIA UNIVERSITY
OF SCIENCE AND TECHNOLOGY
FACULTY OF HEALTH AND APPLIED SCIENCES
DEPARTMENT OF NATURAL AND APPLIED SCIENCES
QUALIFICATION: BACHELOR OF SCIENCE
QUALIFICATION CODE: 07BOSC
COURSE NAME: GENETICS
SESSION: JANUARY 2020
DURATION: 3 HOURS
LEVEL: 6
COURSE CODE: GEN602S
PAPER: THEORY
MARKS: 100
SUPPLEMENTARY / SECOND OPPORTUNITY EXAMINATION QUESTION PAPER
EXAMINER (S): | Prof. Edosa Omoregie
MODERATOR:
Prof. Sylvester Rodgers Moyo
INSTRUCTIONS
Answer all questions in Sections A
Answer any three questions in Section B
Write clearly and neatly
Number your answers correctly
PERMISSIBLE MATERIAL
Scientific Calculator
THIS QUESTION PAPER CONSISTS OF 5 PAGES
(Including this front page)

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SECTION A (MULTIPLE CHOICE QUESTIONS): ANSWER ALL QUESTIONS
[40]
1. Division of the cytoplasm of a eukaryotic cell during mitosis is called?
(2)
A. karyokinesis
B. plamsokinesis
C. diakinesis
D. cytokinesis
2. Synapsis of the homologous chromosomes in the eukaryotic cell occurs during which of
the following phases of division?
(2)
A. anaphase |
B. telophase |
C. prophase |
D. prophase II
E. metaphase II
3. In peas, a tall, yellow-seeded plant is crossed with a homozygous short, green-seeded
plant and yields 203 tall, green-seeded plants, 199 short, green-seeded plants, 207 tall,
yellow-seeded plants, and 192 short, yellow-seeded plants. Which of the following
genotypes is the most likely genotype of the tall, yellow-seeded parent?
(2)
A. TtYy
B. TTYY
C. ttyy
D. ttYY
4. Which of the following is the most likely outcome of a cross between a heterozygous tall
plant and a heterozygous tall plant?
(2)
A. 30 tall : 10 short
B. 20 tall : 20 short
C. 20 tall : 12 medium : 8 short
D. 15 tall : 25 short
5. Which of the following structures indicates that crossing-over has occurred during the
process of mitosis?
(2)
A. centromere
B. synaptonemal complex
C. chiasmata
D. kinetochore
6. Which of the following terms best describes the replication of DNA?
(2)
A. constitutive
B. conservative
C. semi-conservative
D. semi-constitutive
7. In DNA molecule, which of the following bonds is true?
(2)
A. the [G] = [C]

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B. the [G+C] = [A+T]
C. the [G] = [A]
D. none of the above are true
8. During DNA synthesis, the addition of a new nucleotide to a newly formed DNA strand
always proceeds in which direction?
(2)
A. from the promoter
B. in either direction
C. in the 3' to 5' direction
D. in the 5' to 3' direction
9. Which of the following statements is true on the role of the enzyme ligase during the
replication of a DNA molecule?
(2)
A. remove the RNA primer
B. to stabilize the single stranded structure
C. to link okasaki fragments together
D. to unwind the original DNA molecule
10. Which of the following statements is not true about transposons during gene
recombination?
(2)
A. during transposition a short sequence of target DNA is duplicated, and the transposon
is inserted between the directly repeated target sequences.
B. some transposons insert into almost any target DNA sequence.
C. the actions of transposases go on indefinitely without interruption.
D. transposons are important genetic elements because they cause mediate genomic
rearrangement
11. In transcription, RNA polymerase binds at?
(2)
A. a promoter
B. an operator
C. the centromere
D. an enhancer
12. Which of the following statements best describes the Central Dogma theory in genetics? (2)
A. the pattern of genetic information flow in the cell
B. the pattern of chromosomal inheritance in populations
C. the role of mutations in disease
D. the role of promoters
13. During protein synthesis, how many equivalents of ATP are used for each peptide bond? (2)
A.1
B.2
C.3
D.4
14. Which of the following blood genotype belongs to an individual that is regarded as a
universal blood recipient?
(2)

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A. IAIA
B. Ie
G, AF
D. 191°
15. Which of the following autosomal
from Edwards Syndrome?
A. trisomy 18
B. trisomy 21
Cc. X monosomy
D. Trisomy 15
chromosome
conditions
is for an
individual
suffering
(2)
16. Which of the following is the optimum temperature for thermostable DNA polymerase
of Taq polymerase during the PCR experimental step of DNA denaturation?
(2)
A. 94-98°C
B. 100 - 105°C
C. 45 — 50°C
D. 75 — 80°C
17. Which of the following is an assumption for Hardy-Weinberg equilibrium?
(2)
A. no epistasis
B. no dominance
C. no crossing-over
D. no mutation
18. Which of the following autosomal chromosome number is a nullisomy?
(2)
A. 2n-2
B.2n+2
C.2n-1
D.2n+1
19. A human with Turner's
condition?
A. diploid condition
B. euploid condition
C. aneuploid condition
D. haploid condition
syndrome
would
represent
which
of the following
chromosomal
(2)
20. In which section of DNA below is there a mutation?
(2)
|
1
Section 1 | Section 2 Section 3 ; Section4
aa a
GAT:ACT:1CGT:iTGT
BEFORE
;
I
|
|
|
|
|
a aaa
GATIACTICATITGT
AFTER

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A. section 1
B. section 2
C. section 3
D. section 4
SECTION B (ESSAY QUESTIONS): ANSWER ANY THREE QUESTIONS
[60]
21. Using suitable molecular diagram 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.
(20)
22. A. With the aid of suitable diagram, briefly describe the process of mitotic division ina
eukaryotic cell with emphasis on the changes taking place on the chromosome? (12)
B. Briefly differentiate gene mutation from chromosomal mutation.
(2)
C. With the aid of schematic illustration, discuss the process of substitution, insertion and
deletion in gene mutation.
(6)
23. A. With the aid of a suitable schematic diagram, explain the ‘central dogma’ of the
control of gene expression.
(6)
B. If there are 3 x 10° base pairs in the human genome and the mutation rate per
generation per base pair is 10°°, what is the probability that a child will have 4 new
mutations?
(4)
C. Describe the structure of the messenger RNA.
(10)
24. A. There are four accepted concepts in the evolution of population. State these four
concepts and briefly explain Concept 1.
(12)
B. With reference to chromosomal mutation, number of chromosomes, phenotypic
expression and treatment, discuss Turner Syndrome genetic disorder.
(8)