Question

The protein encoded by cry 1Ab controls
A. Tobacco budworm
B. Corn borer
C. Bollworm
D. Armyworm

Answer 1

Hint: The cry gene family is responsible for coding various proteins that help in the eradication of insects and pests.

Complete answer:
The protein encoded by cry 1Ab gene controls ‘Corn borer'.
- Cry proteins are a large family of crystalline toxins produced by the bacteria Bacillus thuringiensis.
- They produce a variety of proteins encoded by the subtypes of the cry gene. Each cry protein is specific to a distinct insect or pest.
- The protein remains in the inactivated stage. Activation of cry protein takes when ingested by insects, due to the alkaline pH of their guts.
- It results in the lysis of epithelial cells of the gut and penetration into the gut wall that leads to the death of insects.
- Humans are taking advantage by incorporating the BT toxin gene in crops to form transgenic crops that are insect resistant e.g., BT cotton.
- The cotton bollworm is controlled by the gene cry IIAb gene.
- Tobacco budworm is controlled by the cry 1Ac gene.
- Armyworm is controlled by the cry 1F gene.

So, the correct answer is Corn borer.

Note: Bacillus thuringiensis, is a naturally occurring Gram-positive bacterium. The cry proteins are produced as an endotoxin in this bacteria. These toxins are harmless to the gut of birds, animals, and human beings as they have an acidic pH in their gut.