Biology on DNA and Griffith's Transformation

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Questions and Answers

What phenomenon did Frederick Griffith discover during his research?

Replicative learning

Transcription

Transformation (correct)

Translocation

How did Griffith classify the virulent strain of Streptococcus pneumoniae?

P for pathogenic

L for lethal

V for virulent

S for smooth (correct)

What characteristic of the pathogenic strain of S. pneumoniae contributes to its virulence?

Lipid bilayer

Deformed shape

Protective polysaccharide coat (correct)

Ribosomal presence

What term describes the non-virulent strain of S. pneumoniae used by Griffith?

R for rough Signup and view all the answers

What was Griffith's primary goal in studying S. pneumoniae?

To develop a vaccine for pneumonia Signup and view all the answers

How many serotypes of S. pneumoniae have been identified based on their capsular polysaccharides?

Ninety Signup and view all the answers

Which of the following statements is true regarding the smooth strain of S. pneumoniae?

It possesses a protective polysaccharide coat. Signup and view all the answers

In the context of Griffith's experiments, which of the following best describes the term 'transformation'?

The process by which bacteria acquire genetic material from their environment. Signup and view all the answers

What was the result when Dr. Griffith injected live type IIR bacteria into mice?

The mice remained healthy with no bacteria found. Signup and view all the answers

What was observed in mice injected with heat-killed IIIS bacteria?

The mice survived without any symptoms. Signup and view all the answers

What was Griffith's best explanation for the development of pneumonia in mice injected with a mixture of living IIR and heat-killed IIIS bacteria?

The IIIS strain transformed the IIR strain into a pathogenic variant. Signup and view all the answers

What did Griffith observe in the blood of mice that developed pneumonia after injection with the mixed bacteria?

Live type IIIS bacteria were isolated. Signup and view all the answers

Which scenario did Griffith consider to be the least likely explanation for his experimental results?

Poor sterilization of the heat-killed bacteria. Signup and view all the answers

What type of bacteria is the IIR strain classified as?

Non-pathogenic strain. Signup and view all the answers

What role did heat play in Griffith's experiments with the IIIS bacteria?

It killed the pathogenic bacteria. Signup and view all the answers

What did Griffith conclude about the transformation capability of bacteria based on his findings?

Bacteria can genetically alter when exposed to certain conditions. Signup and view all the answers

Study Notes

DNA as the Carrier of Genetic Information

Biologists were studying bacterial transformation
Frederick Griffith, an English physician, conducted experiments in 1928
Griffith studied Streptococcus pneumoniae bacteria
Griffith attempted to develop a vaccine against pneumonia
He observed a phenomenon called "transformation"
He found two strains of S. pneumoniae: virulent (pathogenic) and non-virulent (harmless)
Pathogenic strain looked smooth, non-virulent strain looked rough
Injecting live pathogenic bacteria into mice caused pneumonia and death
Injecting heat-killed pathogenic bacteria into mice did not cause disease
Mixing heat-killed pathogenic bacteria with live non-pathogenic bacteria resulted in pneumonia and death in mice
Live virulent bacteria were found in the blood of the mice.
This suggested that genetic information was transferred from the heat-killed pathogenic bacteria to the live non-pathogenic bacteria.

Transforming Agent

Scientists investigated the mechanism behind this transfer.
The mixture of killed pathogenic bacteria released substances that could transform non-pathogenic to pathogenic bacteria
The mixture contained protein, RNA, DNA, lipids and carbohydrates
The question remained - which molecule was the transforming agent?

DNA: The Genetic Material

DNA is the primary genetic material in organisms
DNA carries inheritable characteristics

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Description

Explore the groundbreaking experiments of Frederick Griffith that revealed DNA as the carrier of genetic information. This quiz delves into the transformation phenomenon observed in Streptococcus pneumoniae bacteria and its implications for understanding genetic inheritance. Test your knowledge on bacterial transformation and the early foundations of molecular biology.