Question

Match the scientists of Column I with their contributions in Column II :

Column I		Column II
i.	Griffith	p.	Lac operon
ii.	Jacob & Monad	q.	DNA is the genetic material
iii.	Meselson & Stahl	r.	Transforming principle
iv.	Hershey and Chase	s.	DNA replicates semi-conservatively

• A. i-p, ii-q, iii-r, iv-s
• B. i-p, ii-s, iii-q, iv-r
• C. i-r, ii-p, iii-s, iv-q
• D. i-r, ii-q, iii-p, iv-s

Answer 1

The Correct Option is C

Let's match the scientists listed in Column I with their significant contributions listed in Column II:

• i. Griffith: Frederick Griffith conducted experiments in 1928 with *Streptococcus pneumoniae*, demonstrating that genetic material could be transferred from heat-killed virulent bacteria to live non-virulent bacteria, making them virulent. This phenomenon was termed the Transforming principle (r).  
  So, i → r.
• ii. Jacob & Monad: François Jacob and Jacques Monod proposed the operon model in 1961 to explain the regulation of gene expression in prokaryotes, based largely on their studies of the lactose metabolism system in *E. coli*, known as the Lac operon (p). 
  So, ii → p.
• iii. Meselson & Stahl: In 1958, Matthew Meselson and Franklin Stahl conducted an experiment using density gradient centrifugation and isotopes of nitrogen (¹⁴N and ¹⁵N) to demonstrate that DNA replicates semi-conservatively (s), where each new DNA molecule consists of one old strand and one newly synthesized strand. 
  So, iii → s.
• iv. Hershey and Chase: Alfred Hershey and Martha Chase performed experiments in 1952 using bacteriophages labeled with radioactive isotopes (³²P for DNA and ³⁵S for protein). Their results showed that phage DNA, not protein, entered the bacterial host cell during infection, providing strong evidence that DNA is the genetic material (q). 
  So, iv → q.

The correct matching is:

• i → r
• ii → p
• iii → s
• iv → q

Comparing this to the options provided:

• i-p, ii-q, iii-r, iv-s
• i-p, ii-s, iii-q, iv-r
• i-r, ii-p, iii-s, iv-q
• i-r, ii-q, iii-p, iv-s

The correct option is i-r, ii-p, iii-s, iv-q.

Answer 2

To match the scientists in Column I with their contributions in Column II:

• Gregor Mendel: Mendel is known as the father of modern genetics. He discovered the basic laws of inheritance through his experiments on pea plants. His work led to the formulation of the laws of inheritance of traits.
• Charles Darwin: Darwin is known for his theory of natural selection and is regarded as the father of evolutionary biology. He proposed the theory that species evolve over time due to the process of natural selection.
• James Watson and Francis Crick: These two scientists, along with Maurice Wilkins, are credited with discovering the structure of DNA. They elucidated the double-helix structure of DNA in 1953.
• Louis Pasteur: Pasteur is famous for his work on the germ theory of disease and for developing the process of pasteurization. He demonstrated that microorganisms cause fermentation and disease.

Correct matching:

a. Gregor Mendel → iv. Laws of inheritance

b. Charles Darwin → ii. Theory of natural selection

c. James Watson and Francis Crick → i. Structure of DNA

d. Louis Pasteur → iii. Germ theory of disease

The correct answer is (C) : i-r, ii-p, iii-s, iv-q.