What results from the experiments of Frederick Griffith ...

Question

What results from the experiments of Frederick Griffith provided the strongest support for his conclusion that a transformation factor is responsible for heredity?

Accepted Answer

Hey, everyone. Let's take a look at this question together. Griffith studied streptococcus pneumonia in intending to develop a vaccine, Griffith cultured streptococcus pneumonia in the laboratory and discovered two strains. The R strain and the S strain. These strains varied in their violence or ability to cause disease. Griffith injected both S and R strains into mice based on the results of Griffith's experiments, which of the following is incorrect. Is it answer choice. A S strain injected into mice. The mice died, answer choice B R strain injected into mice. The mice stayed alive. Answer choice C heat killed S strain injected into mice. The mice stayed alive or answer choice. D the mixture of heat killed S and live R strains injected into mice. The mice stayed alive. Let's work this problem out together to try to figure out which of the following statements about the results of Griffith's experiments is incorrect. So we know that in Griffith's experiment involving that streptococcus pneumonia, we have those two strains, the R strain and the S strain which we note that the S strain is the smooth strain, which the smooth strain covers itself with a poly Saar capsule to protect from immune systems. And since this capsule is protecting the S strain from the immune systems of the host, it means that a host injected with the S strain will die since the immune system cannot protect itself from the virus due to that polysaccharide capsule. And we also note that the S strain of streptococcus pneumonia can be killed by beat, which when that S strain is introduced to heat, the remains of the strain will be scattered and joined the R strain. And on the other hand, we know that the, our strain is the rough strain of streptococcus pneumonia in which it does not have the polysaccharide capsule to protect it from the immune systems of the host. So that means that the R strain of streptococcus pneumonia is killed bye the hosts immune system. And so we know that we have that S strain which covers itself with the polysaccharide capsule to protect from the immune systems. And the result is that the host will die. So the S strain kills the host, the R strain that does not have that capsule gets killed by the host's immune system. So the host will live. And when that S strain is introduced to heat, it gets killed by the heat and the remains of the S strain will join the R strain. So we have a combination of the S and the R strain which Griffith learned in his experiment when you have a combination of these two strains, it will kill the host. So now that we know this about the S and R strains of streptococcus pneumonia, we can identify which of the following statements based on the results of Griffith's experiment are incorrect. Answer choice. A says that the S strain injected into the mice results in the mice dying, which we note that the S strain kills the host. So answer choice A is a true statement. Answer choice B says the R strain injected into the mice, the mice will stay live, which we know that when we have that R strain injected into the mice, the host will live. So answer choice B is also a true statement. Answer choice C says that the heat killed S strain. When injected into the mice, the mice will stay alive, which we know is also a true statement. Since the S strain is killed by the heat, it will lead to the host living. So answer choice C is true, which means by process of elimination. Answer choice D, the mixture of heat killed S and live R strains injected into mice will result in the mice staying alive. Is an incorrect statement making it the correct answer. Since we know that this statement is false and that the mixture of the heat killed S and the live R strains will result in the host dying. So the mice will die when injected with the heat killed S and live R strains. So answer choice D is the only statement about the results of Griffith's experiment that is incorrect. So it is the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

What results from the experiments of Frederick Griffith provided the strongest support for his conclusion that a transformation factor is responsible for heredity?

Key Concepts

Griffith's Experiment

Transformation

Avery-MacLeod-McCarty Experiment

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