When we ligate a foreign DNA at the sa/l site of pBR322, the …....a…....plasmid will lose tetracycline resistance due to the insertion of foreign DNA but can still be selected out from …..b….. ones by plating the …...c…..... on ampicillin containing medium.

Options

A. A = Non - recombinant , B = Recombinant, C = Transgormant
B. A = Recombinant , B = Non - recombinant, C = Transgormant
C. A = Transgormant , B = Non - recombinant, C =Recombinant ,
D. A = Recombinant , B = Transgormant C = Non - recombinant,

Answer

To solve the question, we need to fill in the blanks based on the information provided about the pBR322 plasmid and its use in molecular cloning.

### Step-by-Step Solution:

1. **Understanding pBR322**:
- pBR322 is a plasmid vector that contains genes for antibiotic resistance, specifically to ampicillin and tetracycline. It has multiple cloning sites (MCS) where foreign DNA can be inserted.

2. **Insertion of Foreign DNA**:
- When foreign DNA is ligated into the SalI site of pBR322, it interrupts the tetracycline resistance gene. This means that the plasmid will lose its ability to confer resistance to tetracycline.

3. **Identifying the Plasmid Type**:
- After the insertion of foreign DNA, the plasmid is now a recombinant plasmid. Therefore, for blank (a), we can conclude it should be "recombinant".

4. **Selection of Recombinant vs Non-Recombinant Plasmids**:
- To select for the recombinant plasmids (which have lost tetracycline resistance), we need to use a medium that allows us to differentiate between the recombinant and non-recombinant cells. Since the recombinant plasmids can still confer resistance to ampicillin, we can use ampicillin-containing medium for selection.

5. **Plating on Specific Medium**:
- By plating the transformed cells on ampicillin-containing medium, only those cells that have taken up the recombinant plasmid (which are resistant to ampicillin) will grow. Non-recombinant cells (which still have tetracycline resistance but no ampicillin resistance) will not survive on this medium.

6. **Filling in the Blanks**:
- Therefore, the answers to the blanks are:
- (a) recombinant
- (b) non-recombinant
- (c) transformants

### Final Answer:
When we ligate a foreign DNA at the SalI site of pBR322, the **recombinant** plasmid will lose tetracycline resistance due to the insertion of foreign DNA but can still be selected out from **non-recombinant** ones by plating the **transformants** on ampicillin-containing medium.