Match List-I with List-II.
| List-I | List-II |
| (A) Micro-injection | (I) Infects the cell and transfers the recombinant DNA into the host |
| (B) Biolistics (gene gun) | (II) Increases the efficiency with which DNA enters the bacterium through pores in its cell wall |
| (C) Treatment with calcium ions | (III) Recombinant DNA is delivered directly into the nucleus of an animal cell |
| (D) Disarmed pathogen vector | (IV) Plant cells are bombarded with high velocity micro-particles coated with DNA |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-III, B-IV, C-II, D-I
(A) Micro-injection — this matches (III) Recombinant DNA is delivered directly into the nucleus of an animal cell. A fine needle injects the DNA straight into the nucleus.
(B) Biolistics (gene gun) — this matches (IV) Plant cells are bombarded with high velocity micro-particles coated with DNA. The particles are of gold or tungsten, and the method suits plants.
(C) Treatment with calcium ions — this matches (II) Increases the efficiency with which DNA enters the bacterium through pores in its cell wall. Calcium is a divalent cation, and this treatment makes the bacterial cells competent.
(D) Disarmed pathogen vector — this matches (I) Infects the cell and transfers the recombinant DNA into the host. The pathogen can no longer cause disease, but it still delivers the DNA.
NCERT Extract:
Competent Host (For Transformation with Recombinant DNA) – “… This is done by treating them with a specific concentration of a divalent cation, such as calcium, which increases the efficiency with which DNA enters the bacterium through pores in its cell wall. … This is not the only way to introduce alien DNA into host cells. In a method known as micro-injection, recombinant DNA is directly injected into the nucleus of an animal cell. In another method, suitable for plants, cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA in a method known as biolistics or gene gun. And the last method uses ‘disarmed pathogen’ vectors, which when allowed to infect the cell, transfer the recombinant DNA into the host.”