Question

Match the discoveries given under column I with the respective scientists given under column II.

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{1) Discovery of the transforming principle}& \text{A) Avery, Macleod, McCarty}\\ \text{2) Biochemical characterisation of}& \text{B) Hershey and Chase}\\ \text{the transforming principle}& \\ \text{3) Transduction experiment}& \text{C) Griffith}\end{array}$

• A. 1-A, 2-B, 3-C
• B. 1-C, 2-A, 3-B
• C. 1-B, 2-C, 3-A
• D. 1-C, 2-B, 3-A

Answer 1

The correct option is B 1-C, 2-A, 3-B

Transformation is the genetic alteration of a cell that happens as a result of direct uptake and incorporation of genetic material from the surroundings through the cell membrane.

The bacterial transformation was shown by Frederick Griffith in his experiments on Streptococcus pneumoniae. He took two strains of Streptococcus pneumoniae. They were R(non-virulent)and S(virulent) strains.
S-strain was able to cause pneumonia infection in the mouse while R-strain was not. When heat-killed S-strain was mixed with live R-strain, it was able to cause infection in the mouse. He witnessed a miraculous transformation in the bacteria and stated that something was being passed on to the R-strain from the heat-killed S-strain bacteria that transformed it to live S-strain bacteria.

Biochemical characterisation of the transforming principle was performed by Oswald Avery, Colin MacLeod and Maclyn McCarty. They discovered that protein-digesting enzymes and RNA- digesting enzymes did not affect transformation while digestion with DNase inhibited transformation. This is how they concluded that DNA is the hereditary material.

The transduction experiment was done by Alfred Hershey and Martha Chase. They gave unequivocal proof that DNA is the genetic material. They worked with $T_2$ bacteriophages and E.coli bacteria. They discovered that it was the DNA from bacteriophages that was getting transferred into the bacteria by using the radioisotopic technique.

The correct match is

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{1) Discovery of the transforming principle}& \text{C) Griffith}\\ \text{2) Biochemical characterisation of}& \text{A) Avery, Macleod, McCarty}\\ \text{the transforming principle}& \\ \text{3) Transduction experiment}& \text{B) Hershey and Chase}\end{array}$