Exam in: MBV4120/MBV9120 Eukaryotic Genes and Genomes
Day of exam: Friday February 21, 2014
Exam hours: 10.00 – 13.00
This examination paper consists of 2 pages.
Appendices: None
Permitted materials: None
The written exam gives a maximum score of 90 points. Each of the 18 questions gives a maximum score of 5 points each. Give short answers to all questions! Use drawings or figures to illustrate your answer if you like.
Make sure that your copy of this examination paper is complete before answering.
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I Genes and Genomes
1.
What are the C-value and G-value paradoxes?
2.
To what degree do we find gene families in different organisms ranging from prokaryotes to vertebrates? How does the number of gene families relate to genome size?
3.
How does the length of exons compare to the length of introns in different organisms ranging from prokaryotes to vertebrates?
4.
In prokaryotes and unicellular eukaryotes, such as yeast, very few genes have introns, whereas the majority of multicellular eukaryotic genes contain introns. Describe briefly the
“introns early” and the “introns late” models to explain the origin of interrupted genes. Which model has the most support and what is the evidence?
5.
Where are the genes coding for the chloroplast proteome transcribed?
6.
Why have mitochondrial genomes not lost all genes? (Why have organelles retained their genomes?)
II Non-coding RNA and transposable elements
7.
What is a hammerhead ribozyme? How can hammerhead ribozymes be used as tools within biology?
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8.
Describe the three types of small regulatory RNAs found in mammals (miRNAs, esiRNAs and piRNAs)?
9.
What is the transposon-related phenomenon “hybrid dysgenesis” in flies?
10.
What is the difference between a retrovirus and a retrotransposon?
III Rearrangement and Genetic methodology
11.
Describe briefly how the MAT locus switch works. Why is the transposition of HML or HMR to MAT unidirectional?
12.
What is forward genetics and reverse genetics? Describe forward and reverse genetics strategies available for a model organism of your choice.
13.
Make a list of different technologies that allow direct targeting of a gene. What is the difference between these technologies in terms of how DNA and RNA are affected?
14.
Three paralogous genes in the mouse are redundant in terms of gene function. Describe how you could generate a mutant phenotype.
IV Chromosomes and epigenetics
15.
What are telomeres? What is their role?
16.
Describe the components of a nucleosome.
17.
Below are shown four different modified versions of cytosines. Indicate the names of these modified bases. Depict a scheme for active demethylation of 5-methylcytosine in DNA involving a Tet protein and the DNA glycosylase TDG (thymine DNA glycosylase). a b c
18.
Which types of chromatin modifications are recognized by PHD domains? d
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