Frederick Griffith's famous experiment was actually done with mice, not rats. It was when he was trying to develop a vaccine during the Spanish influenza pandemic after WWI. He was using 2 different strains (types) of the bacteria Streptococcus pneumoniae- one was "smooth" and was called the S strain, while the other was "rough" and called the R strain.
The S strain killed the mice within about a day, while the R strain did not. This is because the S strain had a capsule (a slimy layer on its surface) that protected it from the immune system, while the R strain didn't have a capsule and therefore was avirulent (not causing bad effects).
The S strain was then heated to kill the bacteria, and the dead strain was injected into mice, where it didn't have any effect. However, when the dead S strain was mixed with alive R strain bacteria, it did kill the mice. When Griffith studied the bacteria from the dead mice's cells, he found that the R bacteria had acquired capsules. Up until then, scientists had thought the two types of bacteria were separate and could not change.
Griffith concluded that a "transforming principle" from the dead S strain had changed the R strain into the same type of it. This was significant as it led to the discovery of how DNA works (since the "transforming principle" turned out to be DNA), and it was the beginning of modern Molecular Biology.
Frederick Griffith discovered Transformation doing lab experiments in the 1930's. He initially based his work of Gregor Mendel, the father of genetics, and discovered more as he experimented of lab mice.
Griffith discovered bacterial transformation in 1928 by conducting experiments with Streptococcus pneumoniae. This groundbreaking experiment showed that genetic material could be transferred between bacteria, leading to the concept of genetic transformation.
DNA. Oswald Avery and his colleagues demonstrated that the transforming agent responsible for the bacterial transformation in Griffith's experiments was DNA, not protein as previously thought. Their work laid the foundation for understanding the role of DNA in heredity.
The term that describes the concept discovered by scientist Frederick Griffith is "transformation." Griffith's experiments with pneumonia-causing bacteria in mice led to the discovery that genetic material can be transferred between different bacterial strains, causing one strain to inherit traits from the other. This laid the groundwork for understanding the process of genetic transformation.
Avery, MacLeod, and McCarty's experiments in 1944 showed that DNA is the hereditary material in bacteria. The Hershey-Chase experiment in 1952 confirmed that DNA, not protein, is the hereditary material in viruses. These experiments laid the foundation for understanding the role of DNA in storing and transmitting genetic information.
Griffith thought that genetic information was passed along by proteins.http://wiki.answers.com/What_hypothesis_did_griffith_form_from_the_result_of_his_experiment#ixzz15y0eyO5L
Frederick Griffith discovered Transformation doing lab experiments in the 1930's. He initially based his work of Gregor Mendel, the father of genetics, and discovered more as he experimented of lab mice.
Griffith discovered bacterial transformation in 1928 by conducting experiments with Streptococcus pneumoniae. This groundbreaking experiment showed that genetic material could be transferred between bacteria, leading to the concept of genetic transformation.
The difference between "walking pneumonia" and "true pneumonia".
Griffith thought that genetic information was passed along by proteins.http://wiki.answers.com/What_hypothesis_did_griffith_form_from_the_result_of_his_experiment#ixzz15y0eyO5L
griffith's experiment
Griffith's Discovery of Transformation Avery's Experiments with nucleic acidsHershey-Chase Experiment
Frederick Griffith introduced the Griffith experiment in 1928. This experiment proved that bacteria can carry genetic information through a process called transformation.
Griffith' experiment in Biology refers to an experiment that tries discover the "transforming principle" in pneumococcus creatures.
Griffith thought that genetic information was passed along by proteins.http://wiki.answers.com/What_hypothesis_did_griffith_form_from_the_result_of_his_experiment#ixzz15y0eyO5L
Griffith, Avery, Hershey, and Chase
The repeated tests done by scientists to discover or demonstrate something is called experiments.