The choice of Bt-gene for experiment depends upon

Options

A. The host plant/crop
B. Targeted pest/insect
C. Bacillus strain
D. 1 & 2 both

Answer

To answer the question "The choice of Bt-gene for experiment depends upon", we will evaluate the options provided and understand the role of the Bt-gene in pest control.

### Step-by-Step Solution:

1. **Understanding Bt-gene**: The Bt-gene refers to the gene derived from the bacterium *Bacillus thuringiensis*. This gene produces a protein that is toxic to certain insects, making it useful in agriculture as a biological pesticide.

2. **Evaluating Option A - Host Plant Crop**: The choice of the Bt-gene does depend on the host plant crop. If the crop is not resistant to the effects of the Bt-toxin, it could be negatively affected. Therefore, it is crucial to select a crop that can withstand the application of the Bt-gene.

3. **Evaluating Option B - Targeted Pest or Insect**: This option is also significant. The effectiveness of the Bt-gene is contingent upon the targeted pest being susceptible to the Bt-toxin. If the pest has developed resistance to the specific Bt-strain, the application would be ineffective.

4. **Evaluating Option C - Bacillus Strain**: While different strains of *Bacillus thuringiensis* may produce different toxins, the choice of the specific strain is less critical than the host plant and the targeted pest. Therefore, this option is not as crucial in determining the choice of the Bt-gene for an experiment.

5. **Conclusion**: Based on the evaluations, the choice of the Bt-gene for an experiment depends on both the host plant crop and the targeted pest or insect. Thus, the correct answer is option D, which states that the choice depends on both 1 (host plant crop) and 2 (targeted pest or insect).

### Final Answer:
The choice of Bt-gene for experiment depends upon **option D: both the host plant crop and the targeted pest or insect**.

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