Add _____ to soil to prevent chlorosis in plants.

• A. Zinc
• B. Nitrogen
• C. Potassium
• D. Phosphorus

Answer: (A)

Chlorosis happens when leaves yellow because not enough chlorophyll is being made. Zinc acts as a critical cofactor for enzymes involved in chlorophyll synthesis, so when soil zinc is low, these enzymes don’t work well and chlorophyll production drops. Adding zinc supplies what the plant needs for that chlorophyll-building step, helping prevent chlorosis. While nitrogen, potassium, and phosphorus are important for overall plant health, they don’t address this specific chlorophyll-formation bottleneck the way zinc does.