Genetics

1. Why did Beadle and Tatum want an organism that was able to be grown on a chemically defined "minimal" medium to test their hypothesis that a single mutation affected a single enzyme?

2. What was the purpose of growing potential mutants on complete medium following mutagenesis, before testing them for a mutant phenotype?

3. What is a complementation test? Describe how one would perform a complementation test to determine whether two strains that were tryptophan (an amino acid) auxotrophs had mutations in the same gene? What is a tryptophan auxotroph? What would the results of the test be if the mutations were allelic? If they were not allelic?

4. What is the advantage to using a haploid organism like an ascomycete when trying to isolate mutant strains?

5. What does tetrad mean, in tetrad analysis? Why when working with ascomycetes like Neurospora, is this term a bit misleading?

6. What is an ordered tetrad?

7. What do Mendel's two laws mean? These are the Law of Segregation and The Law of Independent Assortment.

• Under what circumstances is the law of independent assortment violated?

8. What is the difference between the first and second divisions of meiosis?

9. What does first division segregation mean vs. second division segregation? What is the significance of these two events? Draw what different asci would look like if first vs. second division segregation occurred for an ascospore pigment mutation?

10. If one gene is further away from the centromere of a particular chromosome than another, why is its crossing over frequency higher?

11. Define the following terms:

auxotroph

prototroph

temperature sensitive mutant

Molecular Biology

1. What are restriction enzymes (REs) and how are they important to a molecular biologist?

• Why are restriction enzymes produced by bacteria? How do they work in bacteria?
• What are plasmids and why are they important?
• What components must a plasmid have to be functional and useful for Molecular biology?

2. Why are fungi considered good experimental organisms for molecular biologists?

3.  Saccharomyces cerevisiae is a model organism for many molecular biological studies.

a.  What features make it a good organism for use as a model system?

b. Why is it a good organism in which to develop potential anti-cancer drugs?

4.  S. cerevisiae was the first eukaryotic organism to have its full genome sequenced.  Why was it a good choice for this endeavor?

b. Why are fungi in general good choices to study eukaryotic genomes?

c.  Can S. cerevisiae be used as a model to study many human diseases?  Explain.

5. What is a Genome library? What materials do you need to make such a library from a fungus?

6. a. What is fungal transformation? Describe three different methods to transform fungi? Explain their advantages and disadvantages.

b. How does the fate of the transforming DNA differ in fungal transformation compared to bacterial transformation? How has this been used to study fungal gene function?

7. Why are fungi used in industry to produce and purify proteins?

8. How does regulation of gene expression differ between fungi (and other eukaryotes) vs. bacteria? (think about the transcripts and also eukaryotic vs. prokaryotic cells).