Arrange the following events in the correct order involved in prepartion of rDNA.
I. Detergent lysis
II. Elution .
III. Restriction enzyme digestion
IV Cell wall degradtion
V. DNA spooling .
VI. Gel electro phoresis .
VII . Ligation with plasmid vector .

Options

A. IV,I,V,III,VI,II,VII
B. IV,I,V,VI,III,II,VIII
C. IV,I,III,V,VI,II,VII
D. I,II,III,IV,VI,V,VII

Answer

To arrange the events involved in the preparation of recombinant DNA (rDNA) in the correct order, we can follow these steps:

1. **Cell Wall Degradation (IV)**: The first step is to degrade the cell wall of the organism from which we want to extract DNA. This is done using specific enzymes depending on the type of cell (e.g., chitinase for fungi, lysozyme for bacteria).

2. **Detergent Lysis (I)**: After the cell wall is degraded, we need to break down the cell membrane. This is achieved through detergent lysis, which disrupts the lipid bilayer of the cell membrane.

3. **DNA Spooling (V)**: Once the cell membrane is lysed, the DNA can be extracted. This is done by adding chilled ethanol, which causes the DNA to precipitate out of the solution. The visible strands of DNA can then be spooled out.

4. **Restriction Enzyme Digestion (III)**: The extracted DNA is then cut at specific sites using restriction enzymes. This allows us to isolate the desired gene or DNA fragment.

5. **Gel Electrophoresis (VI)**: After digestion, the DNA fragments are separated based on size using gel electrophoresis. This technique allows us to visualize and isolate the specific DNA fragments we want.

6. **Elution (II)**: The desired DNA fragment is then extracted from the gel using a process called elution, which allows us to recover the specific DNA we need for further manipulation.

7. **Ligation with Plasmid Vector (VII)**: Finally, the isolated DNA fragment is ligated into a plasmid vector. This step is crucial for transferring the DNA into a host organism for cloning or expression.

### Final Order:
IV → I → V → III → VI → II → VII