Which of the following is correctly matched ?

Options

A. Agrobacterium tumefacines - tumour
B. Thermus aquaticus -Bt-gene
C. pBR 322 -enzyme
D. Ligase- molecular scissors

Answer

To determine which of the following options is correctly matched, let's analyze each option step by step:

### Step 1: Analyze Agrobacterium tumefaciens
- **Agrobacterium tumefaciens** is a bacterium known for causing tumors in plants. It is often used in genetic engineering because it can transfer DNA to plant cells.
- The plasmid associated with Agrobacterium tumefaciens is called the **Ti plasmid** (tumor-inducing plasmid), which can be used to incorporate genes of interest into plants.

**Hint:** Remember that Agrobacterium tumefaciens is key in plant genetic engineering due to its Ti plasmid.

### Step 2: Analyze Thermus Aquaticus
- **Thermus Aquaticus** is a thermophilic bacterium from which the enzyme **Taq polymerase** is derived. Taq polymerase is stable at high temperatures (up to 100°C) and is crucial for the **Polymerase Chain Reaction (PCR)**.
- It is not related to Bt (Bacillus thuringiensis) but is important for DNA amplification techniques.

**Hint:** Taq polymerase from Thermus Aquaticus is essential for PCR due to its heat stability.

### Step 3: Analyze the BT gene
- The **Bt gene** is derived from **Bacillus thuringiensis**, which is used in agriculture to create pest-resistant plants, such as **Bt cotton**. This gene produces a toxin that is harmful to certain insects.

**Hint:** The Bt gene is specifically used for pest resistance in crops.

### Step 4: Analyze PBR322
- **PBR322** is not an enzyme; it is a **plasmid vector** used in genetic engineering, particularly in E. coli, to transfer genes of interest between organisms.

**Hint:** PBR322 is a vector, not an enzyme, and is used for cloning purposes.

### Step 5: Analyze ligase
- **Ligases** are enzymes that join two DNA strands together, often referred to as "molecular glue." They are not referred to as "molecular seizures." The term "molecular scissors" refers to **restriction enzymes**, which cut DNA at specific sites.

**Hint:** Ligases join DNA, while restriction enzymes cut DNA.

### Conclusion
After analyzing all the options, the only correctly matched pair is:
- **Agrobacterium tumefaciens - Tumor (Ti plasmid)**

Thus, the correct answer is the first option.

**Final Answer:** The correctly matched option is **Agrobacterium tumefaciens - Tumor (Ti plasmid)**.