Competent Host and Transformation - Unsolved Practice Set
Chapter: Biotechnology Principles and Processes | Topic: Competent Host and Transformation
COMPETENT HOST AND TRANSFORMATION - UNSOLVED PRACTICE SET
Topic: Competent Host and Transformation
Multiple Choice Questions
Q1. Bacterial cells do not normally take up foreign DNA easily; to make them capable of doing so, they are first treated to become:
- Sterile
- Competent
- Resistant
- Inert
Q2. A common method used to make bacterial cells competent involves treating them with:
- Sugar solution only
- A specific concentration of divalent cations, such as calcium ions
- Only distilled water
- High concentrations of salt with no other treatment
Q3. The heat shock method used in bacterial transformation typically involves:
- Keeping cells at a constant low temperature throughout
- Briefly exposing competent cells to a higher temperature after incubating them on ice with DNA, to encourage DNA uptake
- Boiling the cells for an extended period
- Freezing the cells permanently
Q4. The "gene gun" or biolistic method of gene transfer is particularly useful for introducing DNA into:
- Bacterial cells only
- Plant cells, by physically shooting DNA-coated microscopic particles into them
- Only animal blood cells
- Viruses
Q5. Agrobacterium tumefaciens is notable in biotechnology because it naturally acts as a vector for transferring DNA into:
- Animal cells
- Plant cells
- Bacterial cells only
- Fungal spores only
Short Answer Questions
Q6. What does it mean for a bacterial cell to be "competent," and why is this state necessary for transformation?
Q7. Briefly describe the heat shock method used to introduce foreign DNA into competent bacterial cells.
Q8. What is the biolistic (gene gun) method, and for which type of cells is it particularly useful?
Q9. Why is Agrobacterium tumefaciens considered a naturally occurring, useful tool in plant genetic engineering?
Long Answer Questions
Q10. Describe the process of making bacterial cells competent and subsequently transforming them with foreign DNA using the heat shock method.
Q11. Discuss alternative methods used to introduce foreign DNA into cells that are not easily transformed by standard chemical methods, such as micro-injection, biolistics, and Agrobacterium-mediated transformation.
APPLICATION / ANALYSIS
Q12. A researcher working with plant cells finds that the standard calcium chloride and heat shock method used for bacteria does not work well for introducing DNA into plant cells due to their thick cell walls. Suggest an alternative method the researcher could use, and explain why it would be more suitable for plant cells.
Q13. A biotechnology lab is trying to genetically modify a crop plant to introduce a beneficial gene, and decides to use Agrobacterium tumefaciens as a natural vector for this purpose. Explain, using your understanding of Agrobacterium-mediated transformation, why this bacterium is particularly well-suited for this specific application.