Which of the following is used as genetic vector in plants?

Options

A. Bacillus thuringiensis
B. Agrobacterium tumefaciens
C. E.coli
D. Yest

Answer

To determine which of the following is used as a genetic vector in plants, we will analyze each option provided:

1. **Bacillus thuringiensis**: This bacterium is known for producing the Bt toxin, which is used in genetically modified organisms (GMOs) like Bt cotton for pest resistance. However, it does not serve as a genetic vector for transferring genes into plants.

2. **Agrobacterium tumefaciens**: This is a soil bacterium that is well-known for its role in plant genetic engineering. It contains a plasmid known as the Ti plasmid (tumor-inducing plasmid), which has a specific region called the T-DNA (transfer DNA). This T-DNA can integrate into the plant genome, making Agrobacterium tumefaciens a suitable genetic vector for transferring genes into plants.

3. **Dermifacient**: This term generally refers to agents used in skin treatments and is not related to genetic engineering or plant biotechnology.

4. **E. coli**: While E. coli is a common bacterium used in molecular biology and genetic engineering, it is primarily used as a host organism for cloning and does not serve as a genetic vector for plants.

5. **Yeast**: Yeast is a unicellular eukaryote used mainly in fermentation processes and does not function as a genetic vector for plants.

Based on this analysis, the correct answer is **Agrobacterium tumefaciens**, as it is the only option that acts as a genetic vector in plants.

### Step-by-Step Solution:
1. **Identify the options**: Bacillus thuringiensis, Agrobacterium tumefaciens, Dermifacient, E. coli, Yeast.
2. **Analyze Bacillus thuringiensis**: Understand its role in pest resistance but note it is not a vector.
3. **Examine Agrobacterium tumefaciens**: Recognize its Ti plasmid and T-DNA's role in gene transfer to plants.
4. **Consider Dermifacient**: Identify it as unrelated to genetic vectors.
5. **Review E. coli**: Acknowledge its use in cloning but not as a plant vector.
6. **Look at Yeast**: Note its fermentation role, not related to genetic vectors.
7. **Conclude**: Determine that Agrobacterium tumefaciens is the correct answer.