What strain of bacteria that caused pneumonia grew into?
Griffith conducted his experiments with Streptococcus pneumoniae, a bacterium that causes pneumonia. Griffith worked with two strains of this bacterium called rough (R) and smooth (S). (The two cell types were called “rough” and “smooth” after the appearance of their colonies grown on a nutrient agar plate.)
Who proved that the cause of pneumonia was not a chemical poison released by bacteria?
What result from Griffith’s experiment suggested that the cause of pneumonia was not a chemical poison released by the disease-causing bacteria? When he took a culture of these cells, heated the bacteria to kill them, and injected the heat-killed bacteria into mice; the mice survived.
What bacteria causes pneumonia and killed the mice?
Griffith used two strains of pneumococcus (Streptococcus pneumoniae) bacteria which infect mice – a type III-S (smooth) which was virulent, and a type II-R (rough) strain which was nonvirulent.
What did Griffith’s experiment show quizlet?
What did Griffith’s experiment show? Showed genetic material could be passed between bacteria and cause a change. But when they treated the heat-killed LETHAL bacteria with enzymes to destroy DNA there was NO transformation and the mice lived! DNA was the molecule that caused the genetic change.
When one type of bacteria is changed permanently into another it is called what?
replication. The process during which one type of bacteria is permanently transformed into another is known as transformation.
Which bacteria killed the mice in Griffith’s transformation experiment?
Transformation Experiment. Pneumococcus bacteria include two strains, a virulent S strain with a Smooth glycoprotein coat that kills mice (left), and a non-virulent R Rough strain that does not (middle). Heating destroys the virulence of S (right).
What was Griffith’s conclusion?
Conclusion: Based on the observation, Griffith concluded that R strain bacteria had been transformed by S strain bacteria. The R strain inherited some ‘transforming principle’ from the heat-killed S strain bacteria which made them virulent. And he assumed this transforming principle as genetic material.
What was the conclusion of Avery’s experiment?
Avery and his colleagues concluded that protein could not be the transforming factor. Next, they treated the mixture with DNA-destroying enzymes. This time the colonies failed to transform. Avery concluded that DNA is the genetic material of the cell.