What is a unique feature of Bt crops regarding pest control?

Bt crops, or Bacillus thuringiensis crops, have a distinctive feature that sets them apart in pest management: they produce a bacterial protein that is toxic to specific pests. This protein is derived from the bacterium Bacillus thuringiensis, which is a naturally occurring soil bacterium known for its insecticidal properties.

When certain pests, such as caterpillars of moths and butterflies, consume parts of a Bt crop, the bacterial protein is activated in their gut, leading to their mortality. The specificity of this protein means that it primarily affects targeted pest species while being harmless to many beneficial insects, wildlife, and humans. This targeted approach minimizes the unintended impacts on non-target organisms and reduces the overall reliance on broad-spectrum chemical insecticides, fostering a more sustainable approach to pest management.

In contrast, the other options presented do not accurately reflect the characteristics of Bt crops. For instance, they do not contain synthetic pesticides, are not toxic to all insects, and do not require continuous application of herbicides to manage pests effectively. The unique mechanism of action in Bt crops plays a crucial role in integrated pest management strategies, promoting both crop health and environmental sustainability.