Which of the following microorganisms is best suited as a cloning vector to introduce nematode specific genes in plants ?

Options

A. Phage `lamda`
B. Retrovirus
C. E. Coil
D. Agrobacterium tumefaceins

Answer

To determine which microorganism is best suited as a cloning vector to introduce nematode-specific genes in plants, we can analyze the options provided:

### Step 1: Understand the Role of Cloning Vectors
Cloning vectors are tools used to introduce foreign DNA into host cells. They must be able to replicate within the host and facilitate the expression of the inserted gene.

**Hint:** Cloning vectors should have the ability to integrate and express foreign DNA in the target organism.

### Step 2: Evaluate the Options
1. **Phage Lambda**: This is a bacteriophage that can be used as a vector in E. coli but is not typically used for plant transformation.

**Hint:** Consider whether the vector is suitable for plant cells or primarily for bacterial cells.

2. **Retrovirus**: These are used in gene therapy for animal cells, allowing stable integration of genes into the host genome. However, they are not suitable for plants.

**Hint:** Think about the type of cells the vector is designed to target.

3. **E. coli**: This bacterium is commonly used in molecular biology for cloning and protein expression but does not have the capability to introduce genes into plant cells.

**Hint:** Recall that E. coli is not a plant pathogen and cannot effectively transfer genes into plant cells.

4. **Agrobacterium tumefaciens**: This bacterium is known for its natural ability to transfer DNA to plant cells. It is used extensively in plant biotechnology to introduce foreign genes into plants.

**Hint:** Identify which option is specifically known for its role in plant genetic engineering.

### Step 3: Conclusion
Based on the analysis, **Agrobacterium tumefaciens** is the best-suited microorganism as a cloning vector to introduce nematode-specific genes into plants. It can facilitate the transfer of DNA into plant cells, leading to the expression of the desired genes and potentially providing resistance to nematodes.

**Final Answer:** Agrobacterium tumefaciens