Question

Avery, MacLeod and Mc. Carty used the S(virulent) and R(avirulent) strains of D.pneumococci. They isolated and purified proteins, DNA, RNA, carbohydrates and lipids from the S strain. They treated the living avirulent R strain with each of these chemicals and Identify the transforming principle (DNA).
R-type + Protein S-type $\to$ A-type
R-type + Carbohydrate S-type $\to$ B-type
R-type + DNA of S-type + DNAase $\to$ C-type
R-type + DNA of S-type $\to$ D-type
Identify the type of bacteria(A to D)

• A. (A-type)R+S, (B-type)R+S, (C-type)R+S, (D-type)S
• B. (A-type)R+S, (B-type)S, (C-type)R+S, (D-type)R
• C. (A-type)S, (B-type)S, (C-type)S, (D-type)R
• D. (A-type)R, (B-type)R, (C-type)R, (D-type)S

Answer 1

Answer: (D)

(A-type)R, (B-type)R, (C-type)R, (D-type)S

Avery, MacLeod and Mc. Carty followed Griffiths work and hen prooved the transformation principle.

They found out that the DNA in the S strand bacteria is making the R strain bacteria virulent.

So, the correct option is '(A-type)R, (B-type)R, (C-type)R, (D-type)S'