A common herbicide-resistance mechanism is altered herbicide site of action. Is this statement true or false?

The statement is true because altered herbicide site of action is a well-documented mechanism by which some weeds develop resistance to herbicides. When a weed develops a genetic mutation or modification that changes the site where a herbicide binds, the herbicide can no longer effectively disrupt the target process in the plant. This means that even if the herbicide is applied, it will not have the expected effect of inhibiting growth or causing death to the weed.

This mechanism of resistance highlights the importance of understanding the biological pathways involved in herbicide action. Many herbicides are designed to target specific enzymes or proteins that are critical for plant growth and survival. If the site of action is altered—whether through genetic change or other means—the herbicide may become ineffective, leading to challenges in weed management.

While the statement addresses a general mechanism applicable across various herbicide types, it's essential to consider that not all weeds or herbicides exhibit this resistance mechanism. However, the statement remains true as it correctly identifies a common and significant mechanism of resistance among different weed species.