HORT 250 Fall 1999 Quiz 2

Select the most appropriate answer for each question from the selections provided.

1. Plasmids are used for transformation of E. coli. Which of the following is not a standard component of a plasmid vector:

1. a selectable marker gene
2. restriction enzyme site(s) for inserting other pieces of DNA
3. a gene to stimulate transformation and transfer of DNA
4. an origin of replication
5. all of the above are found in standard bacterial transformation plasmid vectors

2. In transformation of E. coli:

1. only a small fraction of the bacteria will take up the vector DNA
2. all of the DNA will be taken up by the bacteria
3. the bacteria are naturally able to take up DNA
4. none of the above
5. all of the above

3. An example of a selectable marker gene that is widely used in transformation of bacteria is:

1. a gene that makes the bacteria red
2. a gene that allows the bacteria to make auxins and cytokinins
3. a gene that enables the bacteria to make an amino acid
4. a gene that allows the bacteria to grow without lactose in the medium
5. a gene that allows the bacteria to grow in medium containing an antibiotic

4. Which of the following is not part of a standard procedure to transform E. coli:

1. treatment of the bacteria so they will be able to take up DNA
2. mixing the plasmid DNA with the bacteria
3. heat treatment to kill the bacteria and release DNA
4. selection of transformed bacteria

5. A plasmid that is used to express protein X in bacteria will contain which of the following features: (0.5 points for each correct answer, 2 correct answers)

1. the open reading frame for protein X
2. a promoter to drive transcription
3. a site for chromosome insertion
4. border sequences
5. an RNA splicing site
6. a transcription factor gene

6. An advantage of producing proteins in microbes for treatment of medical conditions in humans is that:

1. it requires less regulatory approval than other drugs
2. they are guaranteed to be more effective than other treatments
3. are free from pathogens that can contaminate products made from blood
4. the proteins will be easier to administer to the patient
5. all of the above

7. Kanamycin resistance genes have been widely used in plant transformation. These genes:

1. are exactly the same as those found in bacteria
2. have had the open reading frame altered to function in plants
3. require addition of introns to function in plants
4. require modification of the promoter to function in plants
5. none of the above

8. Agrobacterium tumefaciens has been used for transformation of plants because:

1. it produces tumors on plants
2. the hormones produced in transformed cells allow these cells to be regenerated into plants
3. the bacterium can transfer proteins into plant cells
4. it uses reverse transcriptase to move genes into the nucleus of plant cells
5. the bacterium can move part of the Ti plasmid into the nucleus of plant cells

9. Particle bombardment is effective in transforming plant cells because:

1. DNA attached to metal particles can penetrate into plant cells
2. mechano-stimulation makes DNA stick to these plant cells
3. bombardment makes plant cells competent to take up DNA
4. it allows viral vectors to transmogrify their essence
5. none of the above

10. Each plant cell that is transformed is unique because:

1. the DNA that is inserted into the plant genome is not the same in every cell
2. the DNA inserts into the genome at a different site in each cell
3. the DNA that is transferred replicates as a plasmid and doesn't integrate into a chromosome
4. the DNA is altered as it moves from the bacterium into the plant cell
5. all of the above

BONUS QUESTION

11. Electroporation is another method used to transfer DNA into plant cells. The electric shock treatment is thought to:

1. depolarize the membrane potential
2. liquify the plasmamebrane
3. dissolve the cell wall
4. make pores in the plasmamembrane
5. hypercharge the DNA