Bt-cotton is a GM crop when released for cultivation it will help in :-

Options

A. Pest resistance
B. Herbicide tolerance
C. Increase soil fertility
D. Reduce post-harvest losses

Answer

### Step-by-Step Solution:

1. **Understanding Bt-Cotton**: Bt-cotton is a genetically modified (GM) crop that has been engineered to express a specific protein that acts as an insecticide.

2. **Mechanism of Action**: The protein produced by Bt-cotton comes from the bacterium Bacillus thuringiensis (Bt). This bacterium produces a toxin that is harmful to certain pests, particularly the cotton bollworm.

3. **Genetic Modification Process**: The genetic modification involves inserting the gene that codes for the Bt toxin into the cotton plant's genome. This process is done using transgenic technology.

4. **Effect on Pests**: When pests such as the cotton bollworm feed on the Bt-cotton plant, they ingest the toxin. The toxin binds to the gut wall of the insect, creating pores that lead to cell damage, gut blockage, and ultimately, the death of the insect.

5. **Benefits of Bt-Cotton**: The primary benefit of Bt-cotton is its pest resistance. This means that the crop can withstand attacks from certain insects, reducing the need for chemical pesticides.

6. **Conclusion**: Therefore, when Bt-cotton is released for cultivation, it will primarily help in providing pest resistance, making it an effective tool for farmers to manage pest-related losses.