Mineral Nutrition

Mineral Nutrition in Plants

Mineral Nutrients in plants refer to the absorption of essential mineral nutrients by plants from soil, water, and air. These nutrients are essential for plant growth and development. Mineral uptake in plants ensures proper distribution and metabolism of nutrients. They play a major role in physiological functions within the plant, like enzyme activation, energy transfer, and cell structure formation.

• Mineral - An inorganic element.

• Nutrient - A substance that provides nourishment essential for the maintenance of life and for growth.

Also Read:

• Hydroponics

• Mineral Toxicity

• Symbiotic and Non-Symbiotic Nitrogen Fixation

Plant Nutrients: Macronutrients and Micronutrients

The plants need both non-mineral and mineral nutrients to grow. Non-mineral elements like carbon, hydrogen, and oxygen come from air and water. Mineral nutrients in plants are absorbed from the soil and are classified as macronutrients and micronutrients. Both are essential for plant growth and development. For NEET Biology, mastering plant nutrients is essential. Understanding the difference between macronutrients and micronutrients helps explain nutrient deficiency symptoms and the importance of mineral uptake in plants.

Essential Mineral Nutrients: Criteria in Mineral Nutrition

Mineral Nutrition in Plants is based on the essentials of mineral nutrients. To be considered as an essential mineral nutrient, an element must:

1. Necessary for normal growth: The element must be necessary for the plant to grow and complete its life cycle properly.

2. Cannot be replaced by other elements: The element’s requirement must be specific and cannot be covered by any other element's function.

3. Direct role in metabolism: The element should directly participate in the plant’s metabolic processes.

Example: Magnesium (Mg) is an essential mineral element that cannot be replaced by any other element, as it is a basic component of chlorophyll essential for photosynthesis and necessary as a cofactor for multiple enzymes participating in cellular respiration and various metabolic pathways.

Mineral Uptake in Plants: Absorption Process

Mineral Nutrition in Plants involves the process of mineral uptake and absorption. Mineral uptake involves both passive (apoplast) and active processes (symplast).

1. Initial phase:

• Ions move passively from soil into spaces outside root cells as an apoplast pathway.

• This rapid uptake requires no energy.

2. Metabolic phase:

• Ions enter root cell cytoplasm and vacuoles as symplast pathways via active transport.

• This phase requires metabolic energy.

After absorption, minerals and water move through the xylem vessels. The xylem acts as a tube for transporting nutrients and water to all plant parts. Understanding the mineral uptake process is crucial for NEET Biology. It explains how essential mineral nutrients reach plant tissues and support photosynthesis, growth, and metabolism.

Nutrient Deficiency Symptoms in Plants

The deficiency symptoms of essential elements can be visible in plants, such as direct results of a lack of essential mineral nutrients, such as magnesium and iron. These symptoms are important for NEET Biology as they connect directly to plant physiology NEET notes. Common nutrient deficiency symptoms include:

1. Chlorosis - yellowing of leaves due to lack of chlorophyll (seen in magnesium or iron deficiency)

2. Necrosis - dead patches or spots on leaves (caused by lack of calcium, potassium, etc.)

3. Stunted growth - the plant becomes smaller and weaker

4. Delayed flowering - flowers take longer to form or may not form at all

5. Poor root and fruit development - due to a lack of phosphorus or potassium

6. Falling of leaves or buds - often due to a deficiency of nutrients like zinc or boron

Nitrogen Fixation in Plants: Nitrogen Cycle

Mineral Nutrition in Plants requires nitrogen to grow and metabolise. However, plants can't use atmospheric nitrogen directly. The nitrogen cycle helps convert nitrogen into an absorbable form through a process called nitrogen fixation. This process is vital for plant nutrients and is a key topic in NEET Biology. There are two main ways this happens:

1. Symbiotic Nitrogen Fixation: Plants like legumes (peas, beans) have a relationship with bacteria called Rhizobium. These bacteria live in small swellings on the roots called nodules. They take nitrogen from the air and convert it into ammonia, which the plant can use. In return, the plant gives the bacteria food and shelter.

2. Non-Symbiotic Nitrogen Fixation: Some free-living bacteria in the soil, like Azotobacter and Clostridium, undergo nitrogen metabolism on their own, without needing a plant partner.

Mineral Nutrition in Plants MCQs: NEET Biology

Practising Mineral Nutrition in Plants MCQs is essential for NEET Biology. These questions cover plant nutrients, mineral uptake, nutrient deficiency symptoms, and the nitrogen cycle. Regular practice improves speed, accuracy, and strengthens concepts in plant physiology NEET notes.

Q1. Minerals are absorbed by plants in

1. Colloidal form

2. Ionic form

3. Precipitated form

4. None of these

Correct answer: 2) Ionic form

Explanation:

Minerals in the plant are taken up as ions from the soil into the roots. This is a result of both passive absorption when ions move through concentration gradients without utilizing energy, and active absorption, which requires using energy to force ions against their gradients. Ions of special importance are K⁺ (potassium), Ca²⁺ (calcium), and NO₃⁻ (nitrate). Root hairs increase the absorption efficiency, whereas mycorrhizal fungi also increase mineral absorption, which facilitates essential physiological processes and the neural well-being of plants.

Hence, the correct answer is option 2) Ionic form.

Q2. Which of the following is not a criteria of essentiality of mineral nutrients?

1. Which of the following is not a criteria of essentiality of mineral nutrients?

2. The element must be directly involved in the metabolism

3. In the absence of element, no disorder or malformation in plant should occur

4. The requirement of element must be specific

Correct answer: 3) In the absence of element, no disorder or malformation in plant should occur

Explanation:

The criteria of essentiality are as follows.

1. The element must be necessary for supporting normal growth and reproduction. In the absence of the element, the plants do not complete their life cycle or set the seeds.

2. The requirement of the element must be specific and not replaceable by another element. In

other words, deficiency of any one element cannot be met by supplying some other element.

3. The element must be directly involved in the metabolism of the plant.

4. In the absence of an element a disorder or malformation in plants occur

Hence, the correct answer is option 3) In the absence of an element, no disorder or malformation in the plant should occur.

Q3. The technique of growing plants in a liquid nutrient solution is called

1. Mineral nutrition

2. Hydroponics

3. Aeroponics

4. Both a and b

Correct answer: 2) Hydroponics

Explanation:

Hydroponics is a method of growing plants without soil, using a nutrient-rich water solution to supply the essential nutrients required for plant growth. The roots of the plants are submerged in this nutrient solution, allowing them to absorb water and nutrients directly. Hydroponics can be used to grow a wide variety of plants, including vegetables, herbs, and even fruits, in environments where soil may not be available or suitable for traditional farming. This method offers several benefits, such as faster plant growth, efficient use of water, and the ability to grow in controlled environments like greenhouses or indoors.

Hence, the correct answer is option 2) Hydroponics.

Also Read:

• MCQs on Essential Mineral Nutrients in Plants

• Uptake and Transport of Mineral Nutrients

• Difference between Macronutrients And Micronutrients

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