Examkin

Question

Difficulty: MediumPlant Nutrition and Photosynthesis

Match each essential plant mineral nutrient listed on the left with its corresponding physiological role or deficiency symptom on the right. Which set of alignments correctly matches each mineral element with its specific function in plant metabolism?

  • Magnesium (Mg2+Mg^{2+})Forms the central atom of the chlorophyll porphyrin ring; deficiency causes interveinal chlorosis in mature leaves.
  • Phosphorus (PP)Constituent of nucleic acids and ATP; deficiency results in poor root growth and purplish leaf pigmentation.
  • Potassium (K+K^+)Regulates stomatal opening via guard cell turgor and activates respiratory enzymes; deficiency causes marginal leaf scorch.
  • Nitrogen (NN)Essential component of amino acids, proteins, and nucleic acids; deficiency causes uniform chlorosis of older leaves and stunted growth.

Answer

Magnesium aligns with chlorophyll structure and interveinal chlorosis; Phosphorus aligns with ATP/nucleic acids and purplish leaf pigmentation; Potassium aligns with stomatal turgor regulation and marginal leaf scorch; Nitrogen aligns with amino acid/protein synthesis and general chlorosis.
Magnesium is the structural core of chlorophyll, so its deficiency specifically causes interveinal chlorosis in older leaves. Phosphorus is a fundamental component of nucleic acids and energy-rich ATP molecules; its deficiency impairs root development and promotes purple leaf coloration due to sugar accumulation. Potassium serves as an osmotic agent regulating guard cell turgidity for stomatal movement, and its deficiency manifests as marginal leaf necrosis or scorching. Nitrogen is required for all peptide bonds in proteins and nucleic acids, so its deficiency causes widespread yellowing (chlorosis) and severe stunting.

Step-by-Step Solution

1
Determine the biochemical role and deficiency symptom for Magnesium.
Magnesium occupies the central position in the porphyrin head of chlorophyll molecules.
Deficiency prevents green pigment synthesis specifically between leaf veins, producing interveinal chlorosis.
2
Determine the biochemical role and deficiency symptom for Phosphorus.
Phosphorus forms the sugar-phosphate backbone of DNA/RNA and energy carriers such as ATP.
A lack of phosphorus limits root growth and energy metabolism, accumulating excess carbohydrates that trigger purple anthocyanin pigment synthesis.
3
Determine the physiological role and deficiency symptom for Potassium.
Potassium acts as an inorganic osmotic solute driving water influx into guard cells for stomatal control.
Deficiency disrupts osmotic regulation, causing dehydration of leaf margins and localized tissue death (scorch).
4
Determine the biochemical role and deficiency symptom for Nitrogen.
Nitrogen is the primary structural constituent of amino acids, enzymes, nucleic acids, and chlorophyll.
Deficiency restricts vegetative growth and causes yellowing (chlorosis) as existing nitrogen compounds are broken down and retranslocated.

Key Concept

Essential Plant Mineral Nutrients and Physiological Deficiency Symptoms
Rate this question

Topics

Plant Nutrition and Photosynthesis

More questions from this topic