Microbial Genetics Flashcards
What is the bacterial genome typically?
Singular circular chromosome
Where is the chromosome found in bacteria?
There is no nuclear membrane so it is restricted to a defined region of the bacterial cell known as the nucleoid
What are plasmids?
Other small circular self replicating DNA molecules that are found in the cytosol (separate to the main chromosome)
What is the engine behind horizontal and vertical gene transfer?
Mutation
What is horizontal gene transfer?
Directly from one organism to another
What is vertical gene transfer?
From parent to offspring
What does streptococcus pneumonia cause?
Pneumococcal disease
What is the strains of pneumococcal disease?
Smooth (has a capsule) and rough (no capsule)
What is the deadly strain of pneumococcal disease and why?
Smooth strain because the capsule prevents phagocytosis and being recognised by the immune system
What happened when live smooth cells were injected into the mouse?
The mouse died
What happened when heat treated (dead) smooth cells were injected into the mouse?
The mouse survived
What happened when live rough cells were injected into the mouse?
The mouse survived
What was involved in Griffith’s experiment?
Live rough cells and heat treated (dead) smooth cells injected into the mouse
What were the results of Griffiths experiment?
The mouse died and live smooth cells could be grown on a culture indication that rough cells had been transformed to smooth
What are the types of horizontal gene transfer?
Transformation, conjugation and transduction
