HORT 250 Fall 1999 Quiz 5

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

 

1. Which process in gene expression is blocked by the expression of antisense RNA:

  1. transcription
  2. promoter activity
  3. translation
  4. none of the above
  5. all of the above

 

2. Ethylene is important for tomato fruit ripening because:

  1. it controls the cascade of events that lead to ripening
  2. it improves the flavor of tomatoes
  3. it slows down the rate of fruit ripening
  4. it improves the storage quality of tomatoes
  5. it is an effective pesticide

 

3. Metabolic interference is a term I used to describe a method to metabolize a compound and prevent the synthesis of something that is normally produced. What compound(s) have been targeted for metabolic interference in tomato:

  1. ACC (1-aminocyclopropane-1-carboxylic acid)
  2. AOA (aminooxyacetic acid)
  3. SAM (S-adenosylmethionine)
  4. a & b
  5. a & c

 

4. Increasing the viscosity of juice extracted from tomatoes has been achieved by:

  1. making thicker cell walls
  2. putting less water in the tomato fruit
  3. processing the tomatoes at an earlier stage
  4. reducing the breakdown of cell wall components during ripening

 

5. Which of the following has been widely used to provide resistance against plant viruses:

  1. virus resistance genes from bacteria
  2. expression of virus coat protein genes in transgenic plants
  3. expression of anti-virus genes in vectors that transmit viruses
  4. expression of ribonuclease (RNase) genes in host plants
  5. none of the above

6. Which tropical fruit crop has been successfully engineered to be protected against a lethal virus:

  1. passion fruit
  2. papaya
  3. mango
  4. lychee
  5. kumquat

 

7. What has been the most widely used approach to control plant diseases caused by bacteria:

  1. application of fungicides
  2. application of bactericidal soaps
  3. controlling bacterial vectors
  4. growing varieties with genetic resistance
  5. there are no effective methods to control bacterial diseases

 

8. Pathogenesis-related (PR) proteins are:

  1. expressed when a plant is attacked by a pathogen
  2. expressed only at the site of infection
  3. used for pathogen derived resistance
  4. expressed only in plants that are resistant to the pathogen
  5. only expressed away from the infection site in the systemic acquired resistance response

 

9. In transgenic plants that have been manipulated to express pathogenesis-related (PR) proteins all the time it has been shown that:

  1. these provide no protection at all against pathogens
  2. expression of one PR protein provides high levels of protection against many pathogens
  3. expression of two PR proteins provides some protection against a few pathogens
  4. these proteins trigger the production of other antimicrobial defenses

 

10. Expression of antisense RNA in transgenic plants is a general method used to:

  1. stimulate production of sense RNA to compensate
  2. activate the expression of all genes in a biochemical pathway
  3. eliminate the expression of all genes in a biochemical pathway
  4. block the expression of virus coat protein genes
  5. reduce or eliminate the expression of individual genes

 

BONUS QUESTION

11. Reducing the expression of pectin methylesterase (PME) has resulted in:

  1. plants with resistance to viruses
  2. plants with resistance to bacteria and fungi
  3. tomato juice that has higher viscosity
  4. tomato fruit that last longer before they become rotten
  5. tomato fruit that will not ripen