Which nutrient category includes only micronutrients?

The nutrient category that includes only micronutrients is correctly identified as boron, zinc, copper, molybdenum, iron, manganese, and chlorine. Micronutrients are essential elements that plants require in smaller amounts compared to macronutrients. These specific elements play vital roles in various physiological functions, including enzyme activation, chlorophyll synthesis, and overall plant health.

Macronutrients, on the other hand, are elements such as nitrogen, potassium, and phosphorus, which are involved in growth processes and are needed in larger quantities. Calcium, magnesium, and sulfur also fall into the category of macronutrients, as they contribute to structural functions and metabolic processes in the plant.

Sodium, while it can play a role in some plant processes, is not typically classified as an essential nutrient for most plants, and chlorine, although it is included in the list of micronutrients, is not typically grouped with those essential trace elements. Cobalt, while it does have some importance in certain plants (especially legumes), is likewise not universally classified as a necessary micronutrient.

Thus, boron, zinc, copper, molybdenum, iron, manganese, and chlorine comprise the complete group of micronutrients, emphasizing their role in plant development and nutrition.