- A It forms the primary structural protein backbone found within the rigid plant cell wall in most cases
- B It activates enzymes and is essential for water splitting in photosynthesis (oxygen-evolving complex)
- C It functions mainly as a long-term storage molecule for excess plant carbohydrate reserves under typical conditions
- D It is sometimes thought to directly control the overall rate of root cell elongation alone according to standard textbooks
Correct answer: B. It activates enzymes and is essential for water splitting in photosynthesis (oxygen-evolving complex)
Explanation: Manganese activates many enzymes (decarboxylases, dehydrogenases) and is essential for the oxygen-evolving complex (OEC) of Photosystem II that splits water, releasing O2. Deficiency causes interveinal chlorosis similar to iron deficiency.
Concept context
Essential mineral elements, their roles and deficiency symptoms. Nitrogen fixation and soil nutrition.