The correct option is 3: Zn As students of plant physiology, you must understand that the plant hormone auxin, specifically Indole-3-acetic acid (IAA), is the master regulator of plant growth, controlling processes like cell elongation, root initiation, and phototropism. The question asks for the specific mineral required for the biosynthesis of this critical hormone. The correct answer is Zinc (Zn), a vital micronutrient. Its requirement stems from its role as…Read More