Chapter 12: Mineral Nutrition
NCERT Solutions for CBSE Class 10 Biology — 17 solved questions with detailed explanations.
Solved Questions
Q1. An essential micronutrient for plants is:
- Nitrogen
- Phosphorus
- Zinc
- Potassium
Difficulty: Easy · Topic: Essential Elements
Solution
Zinc is a micronutrient (needed in small amounts). N, P, K are macronutrients.
Q2. Nitrogen fixation in legumes is done by:
- Azotobacter
- Rhizobium
- Nitrosomonas
- Nostoc
Difficulty: Easy · Topic: Nitrogen Fixation
Solution
Rhizobium forms root nodules in legumes and fixes atmospheric N₂ to NH₃ (symbiotic nitrogen fixation).
Q3. Macronutrients needed in large amounts include:
- only N and P
- B, Mo, Cl
- Fe, Mn, Cu, Zn
- N, P, K, Ca, Mg, S
Difficulty: Easy · Topic: Mineral Nutrition
Solution
N, P, K, Ca, Mg, S.
Q4. Micronutrients needed in trace amounts include:
- N, P, K
- Ca, Mg, S
- Fe, Mn, Cu, Zn, B, Mo, Cl
- only Fe
Difficulty: Easy · Topic: Mineral Nutrition
Solution
Fe, Mn, Cu, Zn, B, Mo, Cl.
Q5. Nitrogen deficiency causes:
- no symptoms
- root growth
- chlorosis of younger leaves
- chlorosis of older leaves first
Difficulty: Easy · Topic: Mineral Nutrition
Solution
chlorosis of older leaves first.
Q6. Phosphorus deficiency causes:
- no symptoms
- wilting
- yellow leaves
- purple/dark green leaves
Difficulty: Easy · Topic: Mineral Nutrition
Solution
purple/dark green leaves.
Q7. Potassium deficiency causes:
- no effect
- marginal necrosis of leaves
- wilting
- purple leaves
Difficulty: Easy · Topic: Mineral Nutrition
Solution
marginal necrosis of leaves.
Q8. Nitrification converts:
- N₂ to NH₃
- NO₃⁻ to N₂
- NH₃ to NO₂⁻ then NO₃⁻
- NH₃ to N₂
Difficulty: Easy · Topic: Mineral Nutrition
Solution
NH₃ to NO₂⁻ then NO₃⁻.
Q9. Denitrification converts:
- NO₂⁻ to NH₃
- NO₃⁻ to N₂
- NH₃ to NO₃⁻
- N₂ to NH₃
Difficulty: Easy · Topic: Mineral Nutrition
Q10. Nitrogen cycle involves:
- fixation, nitrification, denitrification, ammonification
- only denitrification
- only fixation
- only nitrification
Difficulty: Easy · Topic: Mineral Nutrition
Solution
fixation, nitrification, denitrification, ammonification.
Q11. Essential element criterion: must be:
- available in soil
- needed for completing life cycle, irreplaceable, directly involved in metabolism
- just present in plant
- absorbed by roots
Difficulty: Easy · Topic: Mineral Nutrition
Solution
needed for completing life cycle, irreplaceable, directly involved in metabolism.
Q12. Hydroponics is growing plants in:
- sand only
- nutrient solution without soil
- air only
- soil only
Difficulty: Easy · Topic: Mineral Nutrition
Solution
nutrient solution without soil.
Q13. Nitrogen is a macronutrient needed for:
- cell wall only
- lipid only
- protein and nucleic acid synthesis
- water transport
Difficulty: Easy-Medium · Topic: Mineral Nutrition
Solution
protein and nucleic acid synthesis.
Q14. Iron deficiency causes:
- chlorosis (yellowing of leaves)
- root rot
- wilting
- leaf drop
Difficulty: Easy-Medium · Topic: Mineral Nutrition
Solution
chlorosis (yellowing of leaves).
Q15. Biological nitrogen fixation is catalyzed by:
- nitrogenase
- rubisco
- amylase
- lipase
Difficulty: Easy-Medium · Topic: Mineral Nutrition
Q16. Carnivorous plants trap insects to obtain:
- oxygen
- water
- nitrogen
- carbon
Difficulty: Easy-Medium · Topic: Mineral Nutrition
Q17. Mycorrhiza helps plants absorb:
- phosphorus
- nitrogen
- oxygen
- carbon
Difficulty: Easy-Medium · Topic: Mineral Nutrition
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