Question

Source organism of cry genes is -

• A. Bacillus thuringiensis
• B. Agrobacterium tumefacien
• C. Rhizobium
• D. Staphylococcus

Hint:

Remember the link: {cry} genes produce insecticidal {cry}stals. They come from {B}acillus {t}huringiensis, the source of the famous {Bt} toxin.

Answer 1

The Correct Option is A

Step 1: Concept Overview:
The question concerns the origin of 'cry genes', crucial for developing insect-resistant transgenic crops.
Step 2: In-Depth Analysis:
cry genes code for Cry proteins, insecticidal crystalline toxins produced by the soil bacterium Bacillus thuringiensis (Bt). These proteins are toxic to specific insect larvae (e.g., caterpillars, beetles, fly larvae).
The abbreviation Bt in crops like Bt-cotton and Bt-brinjal represents Bacillus thuringiensis. The cry genes from this bacterium are isolated and inserted into plants, enabling them to produce the insecticidal protein for pest protection.
Agrobacterium tumefaciens serves as a gene transfer vector but isn't the cry gene source.
Rhizobium is a nitrogen-fixing bacterium.
Staphylococcus is a bacterial genus commonly linked to human infections.
Step 3: Conclusion:
The origin of cry genes is Bacillus thuringiensis.