Mineral Nutrition
Macro and micronutrients, deficiency symptoms, toxicity and nitrogen fixation. (Biology › Transport in Plants and Mineral Nutrition, NEET UG syllabus.)
What is Mineral Nutrition?
An element absolutely necessary for normal growth and reproduction of a plant, whose absence causes specific deficiency symptoms.
Key points
- Define essential mineral elements and state the criteria for essentiality.
- Classify essential elements into macronutrients and micronutrients with examples.
- Describe the major roles of each essential mineral element in plants.
- Identify and explain common deficiency symptoms of essential elements.
Common exam trap
Confusing deficiency symptoms of different elements, especially between mobile and immobile elements.
Definitions
- Term
Essential Element
- Meaning
An element absolutely necessary for normal growth and reproduction of a plant, whose absence causes specific deficiency symptoms.
- Term
Macronutrients
- Meaning
Essential elements required by plants in relatively large quantities (>10 mmol/kg of dry matter).
- Term
Micronutrients
- Meaning
Essential elements required by plants in very small quantities (<10 mmol/kg of dry matter), also known as trace elements.
- Term
Chlorosis
- Meaning
Yellowing of leaves due to loss of chlorophyll, a common deficiency symptom.
- Term
Necrosis
- Meaning
Death of plant tissue, particularly leaf tissue, often appearing as brown spots.
- Term
Nitrogen Fixation
- Meaning
The process by which atmospheric nitrogen (N2) is converted into ammonia (NH3) by certain microorganisms.
- Term
Nitrogenase
- Meaning
An enzyme complex found in nitrogen-fixing microorganisms that catalyzes the reduction of atmospheric nitrogen to ammonia.
- Term
Leg-haemoglobin
- Meaning
An oxygen-binding protein found in the root nodules of leguminous plants, which protects the oxygen-sensitive nitrogenase enzyme.
Learning objectives
Define essential mineral elements and state the criteria for essentiality.
Classify essential elements into macronutrients and micronutrients with examples.
Describe the major roles of each essential mineral element in plants.
Identify and explain common deficiency symptoms of essential elements.
Understand the concept of mineral toxicity.
Explain the process of biological nitrogen fixation, including the organisms and enzymes involved.
Describe the formation of root nodules in legumes.
Prerequisites
Basic understanding of plant cell structure and functions.
Knowledge of photosynthesis and respiration.
General understanding of biological molecules (proteins, carbohydrates, lipids).
Common mistakes
Confusing deficiency symptoms of different elements, especially between mobile and immobile elements.
Misidentifying macronutrients and micronutrients.
Not understanding the specific roles of each element (e.g., Mg in chlorophyll, K in stomatal movement).
Forgetting the anaerobic requirement for nitrogenase activity.
Mixing up the organisms involved in nitrogen fixation (e.g., Rhizobium vs. Azotobacter).
Keywords
Essential elements
Macronutrients
Micronutrients
Deficiency symptoms
Chlorosis
Necrosis
Toxicity
Nitrogen fixation
Nitrogenase
Leg-haemoglobin
Rhizobium
Nodule
Mineral absorption
Practice preview
Which of the following elements is considered a macronutrient for plants?…
easy
Which of the following is an example of a free-living aerobic nitrogen-fixing bacterium?…
easy
Which mineral element is a constituent of chlorophyll, activates enzymes of respiration and photosynthesis, and helps maintain the ribosome structure?…
medium