Question

Match List-I with List-II

List-I: Microorganism & List-II: Genetic principles established
(A). Streptococcus pneumoniae & (I). One gene-one enzyme
(B). Neurospora crassa & (II). RNA is the genetic material
(C). T4 Bacteriophage & (III). DNA is the genetic material
(D). TMV & (IV). Fine structure of gene
Choose the correct answer from the options given below:

• (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
• (A) - (III), (B) - (I), (C) - (II), (D) - (IV)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)

Hint:

Remember these key historical experiments:
- DNA is genetic material: Griffith Avery et al. using Streptococcus.
- One gene-one enzyme: Beadle and Tatum using Neurospora.
- Fine structure of gene: Benzer using T4 phage rII mutants.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Historically, geneticists utilized simple model organisms—such as bacteria, fungi, and viruses—to conduct experiments that established the fundamental principles of molecular genetics.

Step 3: Detailed Explanation:
Let us match each microorganism with the genetic principle it helped establish:
- (A). {Streptococcus pneumoniae: In 1928, Frederick Griffith discovered the "transforming principle" using this bacterium.
In 1944, Avery, MacLeod, and McCarty demonstrated that this transforming substance was DNA, proving that DNA is the genetic material, matching (III).
- (B). {Neurospora crassa: In 1941, George Beadle and Edward Tatum used metabolic mutants of this red bread mold to show that mutations in specific genes cause deficiencies in specific enzymes.
This led to the "One gene-one enzyme" hypothesis, matching (I).
- (C). T4 Bacteriophage (rII locus): In the 1950s, Seymour Benzer used rII mutants of T4 phage to map genetic loci at the nucleotide level.
His work defined the cistron, recon, and muton, establishing the fine structure of the gene, matching (IV).
- (D). TMV (Tobacco Mosaic Virus): In 1956, Gierer and Schramm, along with Fraenkel-Conrat and Singer, demonstrated that the RNA genome of TMV was sufficient to cause viral infection.
This established that RNA can act as genetic material, matching (II).
This gives the matching: (A) - (III), (B) - (I), (C) - (IV), (D) - (II).

Step 4: Final Answer:
The correct match is Option (A).