Match Column 1 with Column 2:
| Column 1 | Column 2 |
| 1) Restriction endonuclease | a) Extrachromosomal DNA |
| 2) Agrobacterium tumefaciens | b) Hind II |
| 3) Plasmids | c) Viruses that infect bacteria |
| 4) Bacteriophages | d) Tumour-inducing (Ti) plasmid |
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 1-b,2-d,3-a,4-c.
(1) Restriction endonuclease — this matches (b) Hind II. Hind II was the first restriction endonuclease to be isolated. It cuts DNA at a particular six base pair sequence.
(2) Agrobacterium tumefaciens — this matches (d) Tumour-inducing (Ti) plasmid. This bacterium carries the Ti plasmid, which has been changed into a cloning vector for plants.
(3) Plasmids — this matches (a) Extrachromosomal DNA. A plasmid is a small circular DNA outside the chromosome that replicates on its own.
(4) Bacteriophages — this matches (c) Viruses that infect bacteria. The name means “bacteria eaters”; these are the viruses Hershey and Chase used.
NCERT Extract:
Principles of Biotechnology – “… The construction of the first recombinant DNA emerged from the possibility of linking a gene encoding antibiotic resistance with a native plasmid (autonomously replicating circular extra-chromosomal DNA) of Salmonella typhimurium.”
Restriction Enzymes – “… The first restriction endonuclease–Hind II, whose functioning depended on a specific DNA nucleotide sequence was isolated and characterised five years later.”
Cloning Vectors – “… The tumor inducing (Ti) plasmid of Agrobacterium tumifaciens has now been modified into a cloning vector which is no more pathogenic to the plants …”
The Genetic Material is DNA – “… They worked with viruses that infect bacteria called bacteriophages.”