Question

Identify the state of DNA (just DNA, in a plasmid, or in a virus) that is transferred from one organism to another in transformation. Explain Griffith’s experiment including if rough and smooth strains of S. pneumonia are pathogenic or nonpathogenic and how the rough strain was changed into a smooth strain of the bacteria?

Answer 1

Answer: The correct answer is : The state of the DNA that is transferred from one organism to another is Naked DNA.

Griffith's experiment went like this:

* Rough strain

* do not cap

Smooth strain

* capsule

* virulent (pathogenic) avirulent

Through DNA-mediated transformation, bacteria enter the DNA

Smooth strain (capsule) -> killed the mouse

Rough strain (no capsule) -> no effect on mouse

Heat killed smooth strain -> no effect on mouse

Heat killed smooth strain + living rough strain mixed -> killed the mouse