Question

Who first identified the transforming principle?

• A. Oswald Avery.
• B. Frederick Griffith.
• C. James Watson.
• D. Rosalind Franklin.

Hint:

The transforming principle was discovered by Frederick Griffith in 1928. However, its identification as DNA was made by Oswald Avery and his team in 1944.

Answer 1

The Correct Option is B

Step 1: Historical background. 
The concept of the "transforming principle" was first proposed by Frederick Griffith in 1928 during his experiments on \textit{Streptococcus pneumoniae}. He demonstrated that genetic material from heat-killed virulent bacteria could transform non-virulent bacteria into virulent ones. Step 2: Role of other scientists. 

Oswald Avery: Later identified the transforming principle as DNA in 1944 through experiments with Avery, MacLeod, and McCarty. 
James Watson: Contributed to the discovery of the structure of DNA alongside Francis Crick. 
Rosalind Franklin: Provided critical X-ray diffraction data that aided in understanding the structure of DNA. 

Step 3: Conclusion. 
Frederick Griffith was the first to propose and demonstrate the existence of a transforming principle, though its identity as DNA was confirmed later by Avery and his colleagues. The correct answer is: Frederick Griffith.