Question

Write a short note on BT cotton.

Hint:

Bt cotton contains a bacterial gene producing Cry protein that kills pests like bollworms, reducing pesticide use and improving yield.

Answer 1

Bt cotton is a genetically modified (GM) variety of cotton that has been developed to resist insect pests, especially the bollworm, which causes severe damage to cotton crops.

Step 1: Development.
The gene for Cry protein was taken from the bacterium Bacillus thuringiensis (Bt). This gene was inserted into cotton plants through genetic engineering.

Step 2: Mode of Action.
The Cry protein, when ingested by insect larvae, gets activated in their alkaline gut. The protein binds to the gut lining, creating pores, which ultimately leads to the death of the pest.

Step 3: Benefits.
\[\begin{array}{rl} \bullet & \text{Provides resistance against bollworm and other insect pests.} \\ \bullet & \text{Reduces dependence on chemical pesticides, making cultivation more eco-friendly.} \\ \bullet & \text{Increases cotton yield and reduces crop losses.} \\ \end{array}\]

Step 4: Limitations.
Excessive and continuous use of Bt cotton may lead to the development of resistance in pests. It also raises concerns about biodiversity and ecological balance.