Which of the following is correctly matched?

Options

A. Agrobacterium tumefaciens - Tumour
B. Thermus aquaticus - Bt - gene
C. pBR322 - Enzyme
D. Ligase - Molecular scissors

Answer

To determine which of the following options is correctly matched, let's analyze each option provided in the question:

1. **Agrobacterium tumefaciens with the tumor**:
- Agrobacterium tumefaciens is a bacterium that causes crown gall disease in plants. It transfers a part of its DNA (T-DNA) into the plant cells, leading to tumor formation. This is a correct match.

2. **Thermus aquaticus with the Bt gene**:
- Thermus aquaticus is a bacterium from which Taq polymerase is derived, used in PCR (Polymerase Chain Reaction). The Bt gene, which provides pest resistance, is actually derived from Bacillus thuringiensis, not Thermus aquaticus. This is an incorrect match.

3. **PBR 322 with the enzyme**:
- PBR 322 is a plasmid vector used in molecular cloning. It is not an enzyme; rather, it is a tool used to carry DNA into a host cell. This is also an incorrect match.

4. **Ligases with the molecular scissors**:
- Ligases are enzymes that join DNA fragments together, while molecular scissors refer to restriction endonucleases, which cut DNA at specific sequences. Therefore, this is another incorrect match.

Based on the analysis, the only correct match is **Agrobacterium tumefaciens with the tumor**.

### Final Answer:
The correctly matched option is **Agrobacterium tumefaciens with the tumor**.