Download BIOL08012 2016 May

School of Science and Sport
Paisley & Hamilton Campus
Session 2015–16
Trimester 2
Module Code: BIOL08012
GENETICS
Date: 13 May 2016
Time:
Duration: 2 hours
Attempt ALL questions in Section A (total 20 marks) using the
multi choice answer sheet provided
Attempt FOUR questions in Section B (total 40 marks) using the
answer booklet provided
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BIOL08012
May 2016
___________________________________________________________________________ Section A
Answer all Questions on the answer grid provided.
Each Question is worth 1 mark.
1.
Which of the following is NOT true of recombination frequency (RF) between
genes?
(a)
(b)
(c)
(d)
2.
Which of the following is true of RNA but not of DNA?
(a)
(b)
(c)
(d)
3.
It contains the base adenine.
It is a polynucleotide.
It has extensive secondary and tertiary structure.
It is unable to be replicated in the cell.
With regard to RNA polymerase, which of the following is false?
(a)
(b)
(c)
(d)
4.
RF can be calculated from the proportion of recombinant offspring.
RF can be used to construct gene maps.
RF gives an exact value for the physical distance between genes.
RF gives an approximate value for the physical distance between genes.
It has a proof-reading function.
It occurs in several different types in the eukaryotic cell.
It acts in a processive manner.
It is a DNA-dependent enzyme.
Phenylketonuria is autosomal and recessive. The frequency of the
phenylketonuria allele is 0.02 (1 in 50). What is the likely frequency of the
disease?
(a)
(b)
(c)
(d)
0.000 01 (1 in 10 000)
0.000 4 (1 in 2 500)
0.004
(1 in 250)
0.002
(1 in 500)
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May 2016
___________________________________________________________________________ 5.
Which of the following states the correct sequence of events in prokaryote DNA
replication?
(a)
(b)
(c)
(d)
6.
Which of the following best describes the role of the promoter?
(a)
(b)
(c)
(d)
7.
unwinding of DNA double helix, attachment of single-strand binding
proteins, synthesis of RNA primer, synthesis of new DNA, separation of
daughter molecules.
separation of daughter molecules, synthesis of RNA primer, unwinding of
DNA double helix, attachment of single-strand binding proteins, synthesis
of new DNA.
unwinding of DNA double helix, separation of daughter molecules,
synthesis of new DNA, attachment of single-strand binding proteins,
synthesis of RNA primer.
attachment of single-strand binding proteins, synthesis of new DNA,
unwinding of DNA double helix, synthesis of RNA primer, separation of
daughter molecules.
The binding site for DNA polymerase to initiate replication.
The binding site for RNA polymerase to initiate transcription.
The binding site for the Ribosome to initiate translation.
The termination site for transcription.
In a PCR reaction, which of the following correctly describes the sequence of
events in a cycle?
(a)
(b)
(c)
(d)
Annealing, extension, denaturation.
Extension, annealing, denaturation.
Denaturation, annealing, extension.
Denaturation, extension, annealing.
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___________________________________________________________________________ 8.
Genes that are repressible are:
(a)
(b)
(c)
(d)
9.
Housekeeping genes.
Usually expressed but can be switched off.
Always expressed at a constant level.
Usually off but can be switched on.
The bonds that join nucleotides in a single strand are:
(a)
(b)
(c)
(d)
5’-3’ phosphodiester bonds.
Hydrogen bonds.
Ionic bonds.
3’-5’ phosphodiester bonds.
10. Which of the following is an example of post-translational processing?
(a)
(b)
(c)
(d)
Cleavage of the signal peptide.
Splicing.
5’-capping.
Peptide bond formation.
11. Which of the following is TRUE concerning mutations?
(a)
(b)
(c)
(d)
All produce phenotypic effects.
They can be caused by environmental factors.
They always involve a large section of a DNA molecule.
They are always inherited.
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May 2016
___________________________________________________________________________ 12. Which of the following is FALSE concerning lethal alleles:
(a)
(b)
(c)
(d)
They can cause a decrease in the total number of individuals born in the
F1 generation.
They always cause death before birth.
They can cause a decrease in the number of phenotypic classes seen in
the F1 generation.
The genes involved probably have a crucial role to play in some aspect of
development.
13. Which of the following is NOT a DNA-binding protein?
(a)
(b)
(c)
(d)
Spliceosome.
Histone.
DNA Polymerase.
RNA Polymerase.
14. The two mechanisms of genetic recombination in higher organisms are:
(a)
(b)
(c)
(d)
Segregation of alleles and chimaerism.
Crossing over and non-disjunction.
Independent assortment and crossing over.
Hybridisation and mosaicism.
15. Recessive disorders are normally only expressed if the recessive allele is
inherited from both parents and the child is homozygous. Which of the following
allow(s) a recessive allele to be expressed even although it has only been
inherited from one parent?
(a)
(b)
(c)
(d)
Pseudodominance.
Imprinting.
Uniparental disomy.
All of the above.
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___________________________________________________________________________ 16. Which of the following terms refers to genetic characteristics that are due to
several genes?
(a)
(b)
(c)
(d)
Polygenic effects.
Multifactorial inheritance.
Multiple allelism.
None of the above.
17. Male pattern baldness is autosomal and dominant. Which of the following
applies to male pattern baldness?
(a)
(b)
(c)
(d)
It cannot be passed from father to son.
It can only be passed from father to son.
It can only be passed from mother to son.
None of the above.
18. If one parent has a dominant genetic characteristic and is heterozygous, and
the other is homozygous recessive, what is the probability of any of their
children inheriting the dominant characteristic?
(a)
(b)
(c)
(d)
¾
½
¼
0
19. Select the correct statement regarding an X-linked dominant trait in humans:
(a)
(b)
(c)
(d)
A female must be homozygous to exhibit the trait.
The trait is more commonly seen in males.
The phenotype of the male is not helpful in determining which allele is
dominant.
It can be passed from father to son.
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___________________________________________________________________________ 20. Which one of the following terms best describes the phenomenon when both
alleles in heterozygotes are expressed and neither is dominant over the other?
(a)
(b)
(c)
(d)
Overdominance.
Heterozygote superiority.
Codominance.
Incomplete dominance.
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BIOL08012
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___________________________________________________________________________ Section B
Answer Four Questions
1. (a)
(b)
Discuss the bonds and interactions between nucleotides that result in
the helical structure of DNA.
(6)
Give an account of the sequence of events that occur in initiation of
RNA synthesis in prokaryotes.
(4)
2. Use appropriate examples compare and contrast simple dominance, codominance and incomplete dominance (partial dominance).
(10)
3. Explain how tRNA fulfils its role as the ‘adaptor’ (or ‘link’) molecule
between RNA structure and protein structure.
(10)
4. Polydactyly (having extra fingers and/or toes) is autosomal and dominant.
(a)
A couple are each heterozygous for polydactyly (Pp). Explain the
proportion of their children would you expect to have the following?
(6)
(i) Polydactyly.
(ii) No polydactyly (normal number of finger and toes).
(b)
Polydactyly shows incomplete penetrance and variable expressivity.
Explain what consequence this has for the phenotype of those who
inherit the polydactyly allele.
(4)
5. (a)
Use ONE example to describe regulatable control of gene expression.
(6)
Describe the role and removal of primers in DNA replication.
(4)
Explain the potential genetic disadvantages of first cousins having
children. (A first cousin is the child of one’s aunt or uncle.)
(6)
Describe the
chimaerism.
(4)
(b)
6. (a)
(b)
differences
between
genetic
END OF EXAM PAPER
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mosaicism
and