Griffith concluded that
something had passed from the heat-killed S strain into the live R strain and transformed it into the pathogenic S strain
. He called this the transforming principle (Figure 2). These experiments are now known as Griffith’s transformation experiments.
What did Griffith’s experiments prove?
Griffith concluded that the heat-killed bacteria somehow converted live avirulent cells to virulent cells, and he called the component of the dead S-type bacteria the “transforming principle.” Fig. 1.1. Schematic diagram of Griffith’s experiment which demonstrates
bacterial transformation
.
What conclusion did Griffith did Griffith make from his experiments?
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 was the most important conclusion from Griffith’s experiment?
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 result from Griffith’s experiment suggested that the?
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 happened when Griffith injected mice with the harmless R strain bacteria alone?
DNA was the transforming factor. What happened when Griffith injected mice with the harmless, R-strain bacteria alone?
The mouse lived.
… The harmless bacteria would not have been transformed, and the mice would have lived.
What happened when Griffith injected mice with R strain virus?
In Griffith’s next experiment, he
mixed the heat-killed, S-strain bacteria with live, harmless bacteria from the R strain
and injected the mixture into laboratory mice. The injected mice developed pneumonia, and many died. The lungs of these mice were filled with the disease-causing bacteria.
What did Avery conclude caused transformation?
What did Avery conclude caused transformation?
DNA was the transforming factor
. … The harmless bacteria would not have been transformed, and the mice would have lived.
What was the purpose of Griffith’s experiment?
Research question: The original purpose of Griffith’s experiment was
to test whether or not the bacteria synthesized their own polysaccharide capsule
. He eventually answered how non-capsulated strains of Pneumococcus bacteria became virulent by providing them with capsular material from another strain.
Why did Griffith call what he saw transformation?
Griffith called the process he observed transformation
because the mouse had been transformed
. the harmful bacteria had been transformed. the harmless bacteria had been transformed.
What was Griffith’s conclusion?
Griffith concluded that
something in the heat-killed S bacteria ‘transformed’ the hereditary properties of the R bacteria
. The nature of this ‘transforming principle’ was unknown.
What was Avery’s conclusion?
Boivin’s conclusion was explicit: “
we should now look to the nucleic acid component of the giant nucleoprotein molecule that forms a gene, rather than to the protein part, to find the inductive properties of the gene”
[20]. Figure 1. Oswald T. Avery in 1944.
What is the conclusion of Hershey and Chase experiment?
Hershey and Chase concluded that
DNA, not protein, was the genetic material
. They determined that a protective protein coat was formed around the bacteriophage, but that the internal DNA is what conferred its ability to produce progeny inside a bacterium.
How did Griffith determine which strain caused disease?
Griffith concluded that
something had passed from the heat-killed S strain into the live R strain and transformed it into the
pathogenic S strain. He called this the transforming principle (Figure 2). These experiments are now known as Griffith’s transformation experiments.
What did Avery’s experiment results show?
In a very simple experiment, Oswald Avery’s group showed that
DNA was the “transforming principle
.” When isolated from one strain of bacteria, DNA was able to transform another strain and confer characteristics onto that second strain. DNA was carrying hereditary information.
How did Avery determine which molecule was most important for transformation?
Avery, MacLeod and McCarty identified
DNA
as the “transforming principle” while studying Streptococcus pneumoniae, bacteria that can cause pneumonia. … After he injected mice with R strain cells and, simultaneously, with heat-killed cells of the S strain, the mice developed pneumonia and died.
