17 Questions
How are natural plasmids primarily found?
In bacteria and fungi
How are non-transmissible plasmids (like cloning vectors) inserted into cells?
By inducing host cells to take up the plasmid DNA
What type of contact is required for natural transmission of plasmids?
Cell-to-cell contact
How does bacterial transformation differ from bacterial conjugation?
Bacterial transformation involves inserting plasmid DNA into cells, while bacterial conjugation involves naked DNA transmission
Which method requires weakening the host cell wall and/or membrane to allow DNA entry into the cell?
Bacterial transformation
Why do cells without plasmids grow the fastest?
They compete with the host for metabolites.
What determines the replication speed of a plasmid in a host cell?
The type of ori in the plasmid.
Which type of plasmids replicate independently of the host chromosome?
Episomes
What characterizes conjugative plasmids?
They have tra genes.
How do non-conjugative plasmids differ from transmissible plasmids?
They lack tra genes.
What effect does reducing antibiotic use have on the incidence of antibiotic-resistant bacteria?
Decreases antibiotic resistance in bacteria.
What is the primary function of the deg plasmid found in Pseudomonas?
Encodes gene products that can degrade certain hydrocarbons
Which plasmid encodes gene products required for nitrogen fixation?
Nif-nod plasmid
What is the main function of the R factor (RTF factor) plasmid in E.coli and Salmonella?
Encodes enzymes that inactivate certain antibiotics
What is a common trait of transmissible plasmids like R factors?
Carry antibiotic resistance genes
What is the significance of antibiotic resistance genes carried by plasmids?
Allow bacterial populations to become resistant to antibiotics
Where are many antibiotic resistance genes located within when carried by plasmids?
Transposons
Explore the characteristics and transmission methods of natural plasmids primarily found in bacteria and fungi. Learn about species specificity, bacterial conjugation, and the differences between naturally transmissible and non-transmissible plasmids.
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