Match Column I with Column II: Column I Column II A. Tumour-inducing…

The correct answer is Option (3) → A-4,B-3,C-2,D-1

(A) Tumour-inducing (Ti) plasmid — this matches (4) Agrobacterium tumefaciens. The Ti plasmid belongs to this bacterium, which causes tumours in dicot plants. It has been changed into a cloning vector that carries genes into plants without causing disease.

(B) Restriction endonuclease — this matches (3) Makes cuts at specific positions within the DNA. “Endo” means inside. These enzymes cut inside the DNA at a particular base sequence.

(C) Exonuclease — this matches (2) Removes nucleotides from the ends of DNA. “Exo” means outside. These enzymes work only at the ends of a DNA strand.

(D) Isolation of purified DNA — this matches (1) Chilled ethanol. After RNA, proteins and other molecules are removed, chilled ethanol makes the purified DNA come out as fine threads.

NCERT Extract:
Restriction Enzymes – “… Restriction enzymes belong to a larger class of enzymes called nucleases. These are of two kinds; exonucleases and endonucleases. Exonucleases remove nucleotides from the ends of the DNA whereas, endonucleases make cuts at specific positions within the DNA.”
Isolation of the Genetic Material (DNA) – “… Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol. This can be seen as collection of fine threads in the suspension (Figure 9.5).”
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 but is still able to use the mechanisms to deliver genes of our interest into a variety of plants.”

Figure 9.5 DNA that separates out can be removed by spooling