Podcast
Questions and Answers
What are the two strains of Pneumococci bacteria that Griffith used in his experiment?
What are the two strains of Pneumococci bacteria that Griffith used in his experiment?
- S strain (correct)
- K strain
- T strain
- R strain (correct)
What is the key difference between the S strain and R strain of Pneumococci bacteria?
What is the key difference between the S strain and R strain of Pneumococci bacteria?
- The S strain is smooth and pathogenic, while the R strain is rough and non-pathogenic (correct)
- The S strain has a capsule and is non-pathogenic, while the R strain lacks a capsule and is pathogenic
- The S strain is rough and non-pathogenic, while the R strain is smooth and pathogenic
The S strain is more susceptible to heat treatment than the R strain.
The S strain is more susceptible to heat treatment than the R strain.
False (B)
Avery and his colleagues continued Griffith's experiment to discover the transforming agent.
Avery and his colleagues continued Griffith's experiment to discover the transforming agent.
What was the method used to eliminate the R strain in Avery's experiment before injecting the extracted substances?
What was the method used to eliminate the R strain in Avery's experiment before injecting the extracted substances?
Which of the following components were isolated from the dead S strain?
Which of the following components were isolated from the dead S strain?
What was injected into the mice along with each isolated component?
What was injected into the mice along with each isolated component?
Only DNA injected with the live R strain killed the mice.
Only DNA injected with the live R strain killed the mice.
What did Avery and his colleagues conclude from their experiment?
What did Avery and his colleagues conclude from their experiment?
Avery and his colleagues carried out a second experiment using enzymes.
Avery and his colleagues carried out a second experiment using enzymes.
What were the enzymes used in Avery's second experiment?
What were the enzymes used in Avery's second experiment?
What was the sample used in Avery's second experiment?
What was the sample used in Avery's second experiment?
The experiment using enzymes further solidified the conclusion that DNA is the genetic material.
The experiment using enzymes further solidified the conclusion that DNA is the genetic material.
Flashcards
Griffith's experiment
Griffith's experiment
An experiment showing that a substance from dead bacteria could change other bacteria to become pathogenic.
S strain
S strain
Pathogenic Pneumococci bacteria with a capsule, forming smooth colonies.
R strain
R strain
Non-pathogenic Pneumococci bacteria without a capsule, forming rough colonies.
Transformation agent
Transformation agent
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Avery's experiment
Avery's experiment
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Heat-killed S strain
Heat-killed S strain
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Biochemical component Isolation
Biochemical component Isolation
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DNA
DNA
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RNA
RNA
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Protein
Protein
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Lipids
Lipids
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Polysaccharides
Polysaccharides
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Bacterial Transformation
Bacterial Transformation
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Hydrolyzing enzymes
Hydrolyzing enzymes
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Pathogenic Bacteria
Pathogenic Bacteria
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Non-pathogenic Bacteria
Non-pathogenic Bacteria
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Genetic material
Genetic material
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Transforming Principle
Transforming Principle
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Capsule
Capsule
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Study Notes
Avery's Experiment Proving DNA as Genetic Material
- Avery and colleagues continued Griffith's experiment to identify the transformation agent
- Griffith used two strains of Pneumococcus bacteria:
- S strain (smooth): forms smooth colonies on agar, has a capsule, pathogenic
- R strain (rough): forms rough colonies on agar, lacks a capsule, non-pathogenic
- Both S and R strains are sensitive to heat
- Griffith's experiment showed a heat-resistant transformation agent transforming R strain to S strain
- Avery's experiments identified the transformation agent:
- Heat-killed S strain pathogens were homogenized
- Isolated and purified biochemical components (protein, RNA, DNA, lipids, polysaccharides) from dead S strain
- Each component was injected into mice with live R strain to determine the transforming agent
Experimental Results
- Table of results: The experiment recorded whether mice lived or died when injected with different treatments(DNA from S + live R, Protein from S + live R, RNA from S+ live R, etc)
- Injection with DNA from S strain + live R strain resulted in death of mice
- Injections with other components did not result in death
Conclusion
- DNA was the transforming agent, capable of converting live R strain bacteria to S strain
- Additional experiments using enzymes to break down polysaccharides, DNA, RNA, and proteins further reinforced the role of DNA
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Description
Explore Avery's groundbreaking experiment that proved DNA is the genetic material responsible for transformation in Pneumococcus bacteria. Learn about the S and R strains and the methods used to isolate the transforming agent. This quiz will test your understanding of these key concepts in molecular biology.
