What process did Griffith discover with his work with pneumonia mice?

What process did Griffith discover with his work with pneumonia mice?

Hear this out loudPauseGriffith had discovered that he could convert the R strain into the virulent S strain. 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.

What was the purpose of the Griffith experiment?

Hear this out loudPauseGriffith’s experiment, reported in 1928 by Frederick Griffith, was the first experiment suggesting that bacteria are capable of transferring genetic information through a process known as transformation.

What was Griffith trying to learn when he set up mice experiment?

Hear this out loudPause12–1 DNA. In 1928, British scientist Fredrick Griffith was trying to learn how certain types of bacteria caused pneumonia. He isolated two different strains of pneumonia bacteria from mice and grew them in his lab.

When Griffith injected a mouse with rough bacteria What happened to the mouse?

Hear this out loudPauseIn 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 did the experiments that Frederick Griffith performed with R and S pneumonia bacteria and mice tell us about heredity in the cell?

Hear this out loudPauseGriffith found that mice inoculated with either the heat-killed virulent bacteria or the living avirulent bacteria remained free of infection, but mice inoculated with a mixture of both became infected and died.

Why did Griffith call what he saw transformation?

Hear this out loudPauseGriffith 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 did Griffith learn from his experiment?

Hear this out loudPauseFrederick Griffith, (born October 3, 1877, Eccleston, Lancashire, England—died 1941, London), British bacteriologist whose 1928 experiment with bacterium was the first to reveal the “transforming principle,” which led to the discovery that DNA acts as the carrier of genetic information.

What did Griffith hope to learn from his experiment?

What question was Griffith trying to answer with his experiments?

Hear this out loudPauseFrederick Griffith: Bacterial transformation. In 1928, British bacteriologist Frederick Griffith conducted a series of experiments using Streptococcus pneumoniae bacteria and mice. Griffith wasn’t trying to identify the genetic material, but rather, trying to develop a vaccine against pneumonia.

What happens when mice are injected with dead smooth bacteria?

Hear this out loudPauseWhen heat-killed smooth cells are injected into a mouse, the mouse lives. Rough strain & heat-killed smooth strain. When these two types of cells are injected into a mouse as a mixture, the mouse gets pneumonia and dies.

Why the mouse dies when the mixture of heat killed S strain and live R strain of Streptococcus pneumonia is injected?

Hear this out loudPauseThe R strain is non-pathogenic (does not cause disease). The S strain is pathogenic (disease-causing), and has a capsule outside its cell wall. The capsule allows the cell to escape the immune responses of the host mouse. When Griffith injected the living S strain into mice, they died from pneumonia.

What did the Hershey-Chase experiment prove?

Hear this out loudPauseThe Hershey-Chase experiment, which demonstrated that the genetic material of phage is DNA, not protein. The experiment uses two sets of T2 bacteriophages. In one set, the protein coat is labeled with radioactive sulfur (35S), not found in DNA.

How did Griffith isolate pneumococcus from dead mice?

Griffith was also able to isolate both live II-R and live III-S strains of pneumococcus from the blood of these dead mice. Griffith concluded that the type II-R had been “transformed” into the lethal III-S strain by a “transforming principle” that was somehow part of the dead III-S strain bacteria.

What kind of bacteria was used in Griffith’s experiment?

In Griffith’s experiment, he mixed heat-killed S-strain bacteria with live, harmless bacteria from the R-strain. When this mixture was injected into mice, the mice developed pneumonia, died.

How did mice get pneumonia and how did they die?

By themselves, neither should have made the mice sick. To his amazement, mice developed pneumonia and many died. When he looked at lungs, he saw they were not filled with harmless bacteria, but with disesase causing bacteria. Somehow the heat-killed bacteria had passed their disease causing ability to the harmless strain.

What did transformation do to make mice sick?

Transformation – mixed his heat-killed, disease-causing bacteria with live, harmless ones and injected the mixture into mice. By themselves, neither should have made the mice sick. To his amazement, mice developed pneumonia and many died.

How did the mice in the Griffith experiment die?

The one which was infected with the S strain developed pneumonia and died while that infected with the R strain stayed alive. In the second stage, Griffith heat-killed the S strain bacteria and injected into mice, but the mice stayed alive.

What was the second stage of the Griffith experiment?

In the second stage, Griffith heat-killed the S strain bacteria and injected into mice, but the mice stayed alive. Then, he mixed the heat-killed S and live R strains. This mixture was injected into mice and they died. In addition, he found living S strain bacteria in dead mice.

What kind of bacteria can be found in dead mice?

In addition, he found living S strain bacteria in dead mice. 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.

How did bacterial pneumonia cause most deaths in 1918?

In most cases, he adds, the predominant disease at the time of death appeared to have been bacterial pneumonia. There also was evidence that the virus destroyed the cells lining the bronchial tubes, including cells with protective hair-like projections, or cilia.