Minerals in Plant Metabolism Practice Questions
17 free Minerals in Plant Metabolism practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
The element required by plants for the synthesis of the two amino acids, Methionine and Cysteine, is:
- A Phosphorus
- B Nitrogen
- C Sulfur
- D Iron
Correct answer: Sulfur
Sulfur is a vital constituent of amino acids like cysteine and methionine. It is also found in several coenzymes, vitamins (thiamine, biotin), and ferredoxin.
Which mineral element is required for the photolysis of water during photosynthesis to liberate oxygen?
- A Magnesium and Iron
- B Copper and Zinc ions
- C Boron and Molybdenum only
- D Manganese and Chlorine
Correct answer: Manganese and Chlorine
Manganese (Mn2+) and Chlorine (Cl-) are essential for the water-splitting reaction in Photosystem II. This process is necessary to provide electrons for the light reaction and release oxygen.
Which of the following elements is responsible for maintaining the turgidity of cells and the opening and closing of stomata?
- A Calcium
- B Sodium
- C Potassium
- D Phosphorus
Correct answer: Potassium
Potassium (K+) is the major osmoticum in plant cells. It regulates stomatal movement by changing the turgor pressure of guard cells and acts as an activator for many enzymes.
The micronutrient required for the synthesis of Auxin (IAA) is:
- A Copper (Cu)
- B Boron (B)
- C Zinc (Zn)
- D Manganese (Mn)
Correct answer: Zinc (Zn)
Zinc (Zn2+) is an essential activator for the enzyme carboxylase and is specifically involved in the biosynthesis of the plant hormone auxin.
Which element is a critical component of the enzyme Nitrogenase and Nitrate reductase?
- A Molybdenum
- B Boron (B)
- C Iron (Fe2+)
- D Zinc (Zn2+)
Correct answer: Molybdenum
Molybdenum (Mo) is a component of several enzymes involved in nitrogen metabolism. It is indispensable for the function of nitrogenase in nitrogen fixation and nitrate reductase in nitrate assimilation.
Calcium is required by plants for which of the following physiological processes?
- A Structural component of the middle lamella
- B Regulation of stomatal opening and closing
- C Synthesis of chlorophyll pigments in leaves
- D Fixation of atmospheric nitrogen in roots
Correct answer: Structural component of the middle lamella
Calcium ions bind with pectin to form calcium pectate, a key structural component of the middle lamella that cements adjacent plant cell walls together. Stomatal regulation depends on potassium, and chlorophyll synthesis depends on magnesium and nitrogen, not calcium, so those options are incorrect for this element.
Which element is involved in the translocation of carbohydrates (sugars) through the phloem?
- A Boron
- B Molybdenum
- C Manganese
- D Iron
Correct answer: Boron
Boron is necessary for pollen germination, cell elongation, and the translocation of sugars. It is absorbed as borate ions and is relatively immobile in plants.
Iron (Fe) is absorbed by plants primarily in which form?
- A Ferrous (Fe2+)
- B Ferric (Fe3+)
- C Elemental Iron
- D Iron Oxide
Correct answer: Ferrous (Fe2+)
Plants absorb iron mainly in the ferrous (Fe2+) form. Although iron exists in soil predominantly as insoluble ferric (Fe3+) compounds, root cells reduce Fe3+ to the more soluble Fe2+ form using ferric chelate reductase before it is taken up by iron transporters.
Which essential element is a constituent of all nucleic acids, proteins, and chlorophyll?
- A Nitrogen
- B Phosphorus
- C Sulfur
- D Magnesium
Correct answer: Nitrogen
Nitrogen is the essential element required in the greatest amount by plants. It is a fundamental constituent of amino acids, proteins, nucleic acids, vitamins, and hormones.
Copper (Cu) plays an essential role in plant metabolism as a component of:
- A Enzymes involved in redox reactions
- B Cell wall structure formation
- C Nitrogen fixation processes exclusively
- D Starch storage in plastids
Correct answer: Enzymes involved in redox reactions
Copper is essential for the overall metabolism of plants. It is a component of enzymes like plastocyanin and cytochrome oxidase, which are involved in redox (oxidation-reduction) reactions.
Phosphorus is a constituent of which of the following?
- A Cell membranes and proteins
- B Nucleic acids and nucleotides
- C ATP and phosphorylation reactions
- D All of the above are correct
Correct answer: All of the above are correct
Phosphorus is absorbed as phosphate ions. It is a structural component of phospholipids in membranes, nucleic acids (DNA/RNA), and energy carriers like ATP.
The deficiency symptom 'Chlorosis' (yellowing of leaves) is caused by the lack of:
- A Nitrogen, Potassium, Magnesium
- B Sulfur, Iron, Manganese
- C Zinc, Molybdenum
- D All of the above are correct
Correct answer: All of the above are correct
Chlorosis is the loss of chlorophyll leading to yellowing. It is caused by the deficiency of several elements, including Nitrogen, Potassium, Magnesium, Sulfur, Iron, Manganese, Zinc, and Molybdenum.
Necrosis, or the death of tissue (particularly leaf tissue), is a characteristic deficiency symptom of:
- A Ca, Mg, Cu, K
- B N, S, Mo
- C Fe, Mn, Zn
- D P, B, Cl
Correct answer: Ca, Mg, Cu, K
Necrosis is specifically associated with the deficiency of Calcium, Magnesium, Copper, and Potassium. These elements are vital for maintaining cellular structural integrity and metabolic activity.
Deficiency of which elements leads to the inhibition of cell division in plants?
- A N, K, S, Mo
- B Ca, Mg, Cu
- C Fe, Mn, B
- D P, Zn, Cl
Correct answer: N, K, S, Mo
Low levels of Nitrogen, Potassium, Sulfur, and Molybdenum can cause a significant decrease in the rate of cell division, leading to stunted plant growth.
Which of the following elements is considered a 'Beneficial Element' required by some higher plants but not necessarily all plants?
- A Boron
- B Silicon
- C Phosphorus
- D Magnesium
Correct answer: Silicon
Sodium, Silicon, Cobalt, and Selenium are termed 'beneficial elements.' They are required by some higher plants (e.g., silicon for grasses) but are not part of the standard 17 essential elements.
Elements that are actively mobilized within the plant and exported to young developing tissues show deficiency symptoms first in:
- A Younger leaves
- B Older leaves
- C Roots
- D Flowers
Correct answer: Older leaves
For mobile elements like Nitrogen, Potassium, and Magnesium, the plant breaks down molecules in older leaves to export nutrients to the growing tip. Thus, older leaves show deficiency symptoms first.
Which element is relatively immobile in plants, causing its deficiency symptoms to appear first in young tissues?
- A Nitrogen
- B Magnesium
- C Calcium
- D Potassium
Correct answer: Calcium
Calcium and Sulfur are structural components (like the cell wall) and are not easily mobilized. Therefore, they cannot be moved to new leaves, and deficiency symptoms appear in young tissues first.