Chlorosis in older leaves occurs due to the deficiency of?

Review the verified answer and explanation for this SPSC – Sindh Public Service Commission past-paper question on CampusFin.

Chlorosis in older leaves occurs due to the deficiency of? Answer: Magnesium

Chlorosis in older leaves is often due to a deficiency in nitrogen, magnesium, or manganese, as these nutrients are essential for chlorophyll formation and are either immobile or mobile in a way that affects older tissues first when deficient. In contrast, iron deficiency typically affects younger leaves first.

Question context

This question is part of 🔬 General Science within the broader 🌐 Current Affairs & GK subject and appears in the SPSC – Sindh Public Service Commission preparation collection. Reviewing the answer together with nearby questions helps reinforce the underlying concept and identify how it may appear in competitive exams.