Griffith's Experiment and Genetic Transformation

In 1928, Frederick Griffith conducted an experiment on bacterial transformation, demonstrating that DNA is the hereditary material. He used two strains of bacteria: a virulent smooth strain (S) and a harmless rough strain (R). Injecting S strain into mice caused death, while R strain did not. However, when heat-killed S strain was mixed with live R strain and injected, the mice died, indicating that the R strain had transformed into the virulent S strain. This transformation was due to the transfer of DNA from the dead S strain to the live R strain.

What was the primary focus of Griffith's experiment conducted in 1928?

• To develop a new type of bacteria

• To understand the role of DNA in heredity

• To study the effects of antibiotics

• To discover a cure for pneumonia

Which characteristic distinguished the virulent strain S from the harmless strain R in Griffith's study?

• Strain R was resistant to antibiotics

• Strain S had a rough surface

• Strain S had a smooth polysaccharide coat

• Strain R could not survive in mice

What was the outcome when Griffith injected live R strain bacteria into mice?

• The mice died

• The mice developed immunity

• The mice remained healthy

• The bacteria transformed into strain S

What happened when Griffith mixed heat-killed S strain with live R strain bacteria and injected them into mice?

• The mice developed a mild illness

• The mice died

• The mice remained healthy

• The bacteria were destroyed

What did Griffith's experiment demonstrate about the nature of genetic material?

• Lipids are crucial for genetic transformation

• DNA can transform the properties of bacteria

• Proteins are the genetic material

• RNA is responsible for heredity

What is the term used to describe the process of changing the character of one strain by transferring DNA from another strain?

• Translocation

• Translation

• Transformation

• Transcription

Why was the transformation observed in Griffith's experiment significant for genetics?

• It proved that bacteria can mutate naturally

• It showed that DNA is the molecule responsible for heredity

• It demonstrated that proteins are the carriers of genetic information

• It indicated that environmental factors can alter genetic material