What happened to the mice that were injected with the R strain of pneumonia?
In contrast, when Griffith injected the live R strain into mice, they survived. In another experiment, when he injected mice with the heat-killed S strain, they also survived. This experiment showed that the capsule alone was not the cause of death.
What happened when Griffith injected the mice?
In the critical experiment, Frederick Griffith (1928) mixed heat-killed S with live R and injected the combination into mice: the mouse died. The dead mouse's tissues were found to contain live bacteria with smooth coats like S.
What happened when Griffith injected the S strain bacteria into the healthy mouse?
Griffith's Experiments When Griffith injected mice with disease-causing bacteria, the mice developed pneumonia and died.
What happened in Griffith's experiment with pneumonia bacteria?
In this experiment, Griffith mixed the living non-virulent bacteria with a heat inactivated virulent form. He subsequently infected mice with this mixture and much to his surprise, the mice developed pneumonia and died. Furthermore, he was able to isolate colonies of the virulent strain from these mice.
What strain of the bacteria was found in the blood samples of the mice?
After he injected mice with R strain cells and, simultaneously, with heat-killed cells of the S strain, the mice developed pneumonia and died. In their blood, Griffith found live bacteria of the deadly S type. The S strain extract somehow had "transformed" the R strain bacteria to S form.
What did Griffith expect to happen when he injected living R strain and dead S strain together?
Griffith also injected mice with S-strain bacteria that had been killed by heat. As expected, the killed bacteria did not harm the mice. However, when the dead S-strain bacteria were mixed with live R-strain bacteria and injected, the mice died. DID YOU KNOW?
Which result was the surprising result in Griffith'S experiment the mice injected with the?
To Griffith's surprise, however, the injected mice developed pneumonia, and many died. When he examined the lungs of these mice, he found them to be filled not with the harmless bacteria, but with the disease causing bacteria.
What was the most significant conclusion of Griffith'S experiments with pneumonia in mice?
What was the most significant conclusion of Griffith's experiments with pneumonia in mice? There is a substance present in dead bacteria that can cause a heritable change in living bacteria.
What happened when the samples of bacteria were injected into the mice select all that apply?
- When live, harmless bacteria were injected, the mice did not die. - When heat-killed, disease-causing bacteria and harmless bacteria were injected together, the mice were killed.
What was the conclusion of Griffith'S work with Streptococcus pneumoniae?
Griffith concluded that the R-strain bacteria must have taken up what he called a "transforming principle" from the heat-killed S bacteria, which allowed them to "transform" into smooth-coated bacteria and become virulent.
What happened in Griffith'S experiment?
In this experiment, bacteria from the III-S strain were killed by heat, and their remains were added to II-R strain bacteria. While neither harmed the mice on their own, the blend of the two was able to kill mice. Griffith was also able to get both live II-R and live III-S strains of S.
What conclusions can you draw from Griffith'S experiment?
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.
Why was Griffith surprised when the mice injected with both harmless?
By themselves, neither type of bacteria should have made the mice stick. To Griffith's surprise, however, the injected mice developed pneumonia, and many died. When he examined the lungs of these mice, he found them to be filled not with the harmless bacteria, but with the disease-causing bacteria.
Why was Griffith surprised when the mice injected with both harmless and heat killed bacteria?
Why was Griffith surprised when the mice injected with both harmless and heat-killed bacteria developed pneumonia and died? He was surprised because the cells had been rendered inactive due to the heat killing process. He expected the mice to be filled with harmless bacteria.
What part of the bacteriophage gets injected?
Lytic cycle Entry: The phage injects its double-stranded DNA genome into the cytoplasm of the bacterium.