Micronutrients: Definition, Function, Types, Examples

What Are Micronutrients?

Micronutrients are essential elements that are needed by the organism in traces for proper growth, development, and good health. The nutrients play their roles coupled with vitamins and minerals, playing a crucial role in several physiological processes. These activities range from metabolic to immune functions and cellular repair. Although only needed in trace quantities, micronutrients are vital to achieving optimum health in both humans and plants.

Importance Of Micronutrients

Micronutrients are those nutrients that are needed in very small amounts to ensure proper functioning. Micronutrients help in the regulation of biochemical reactions, maintenance of the immune system, and formation of hormones and enzymes. Deficiencies in their levels could result in quite several health complications, such as impaired cognitive function, weakened immune response, and developmental disorders.

Classification Of Micronutrients

The micronutrients can generally be classified under two heads: vitamins and minerals.

Vitamins – Classification And Functions

Vitamins are organic compounds, essential to various activities of the human body. They may be broadly classified into two categories:

Water-Soluble Vitamins

Water soluble vitamins dissolve in water and are never stored by the body. They include Vitamin C and the B-complex vitamins like B1, B2, B3, B6, B12, folate, and biotin. Excess amounts are removed through urine. Hence, regular intake is necessary.

Fat-Soluble Vitamins

Fat soluble vitamins are soluble in fats and deposited in the liver as well as in adipose tissues. Fat-soluble vitamins form some of the most vital vitamins, including A, D, E, and K, which provide activities in vision, the health of bones, and immune response.

Microminerals (Trace Elements) – Functions & Deficiency

Minerals are the inorganic elements. However, they play an important role in various physiological processes. They can be further divided into:

Major Minerals: These are needed in higher quantities and they include calcium, phosphorus, magnesium, sodium, potassium, and sulfur. They are involved in the development of good bone health, have muscle functions, and maintain fluid balance.

Trace Minerals: These make up trace minerals, which are also needed in very small quantities: iron, zinc, copper, manganese, selenium, and iodine. They play key roles in the functioning of enzymes, the formation of hormones, and in immune function.

Micronutrients In Plants

Micronutrients are of equal importance for the health and growth of plants. The most essential micronutrients for plants are boron, zinc, manganese, iron, copper, molybdenum, and chlorine. All these nutrients have a specialized nature of function in plant physiology.

Effects Of Micronutrient Deficiency

Deficiency in micronutrients causes severe health problems in both human beings and plants. In human beings, deficiencies cause conditions such as anaemia—iron deficiency, goitre—iodine deficiency, rickets—vitamin D, and impaired vision due to the deficiency of vitamin A. In plants, deficiencies cause stunted growth, chlorosis, poor flowering and reduced yield.

Sources Of Micronutrients

Humans can consume a good balanced diet varied in fruits, vegetables, whole grains, lean proteins, and dairy products. It is an excellent source of adequate vitamins and minerals. Plants absorb micronutrients from soil solution and fertilizers like FeSO₄, ZnSO₄, Borax. Supplements may sometimes be required, but a supplement regime is always to be undertaken with caution and under professional supervision.

Prevention Of Micronutrient Deficiency

In order to stay healthy and prevent from micronutrient deficiency following steps can be taken:

• Consumption of a balanced diet including a variety of food sources

• Use of biofortified crops i.e., plants that have higher levels of vitamins and minerals like Zn, Fe and vitamin A.

• Soil testing and fertiliser supplementation in agricultural practices.

Micronutrients NEET MCQs (With Answers & Explanations)

The key concepts to be covered under this topic for different exams are:

• Classification of Micronutrients

• Vitamins, its type and role

• Micronutrients in plants

Practice Questions for NEET

Q1. Plants deficient in zinc, show reduced biosynthesis of growth hormone

1. Cytokinin

2. Auxin

3. Ethylene

4. Abscisic acid

Correct answer: 2) Auxin

Explanation:

• Zinc-deficient plants produce less auxin, a growth hormone.

• Auxin requires tryptophan, which zinc aids in producing. Insufficient zinc causes plants to develop slowly, and have yellow areas, short stems, and little leaves.

• Alkaline soils frequently have zinc deficiencies, which can be remedied with zinc fertilizers.

Hence, the correct answer is option 2)Auxin.

Q2. Which one of the following is not a micronutrient?

1. Boron

2. Molybdenum

3. Magnesium

4. Zinc

Correct answer: 3) Magnesium

Explanation:

Micronutrients are essential elements required by organisms in small quantities for proper growth and development. In plants, they are needed in amounts equal to or less than 0.1 mg per gram of dry weight. Iron, Magnesium, Zinc, Copper, and bd are micronutrients.

Hence, the correct answer is option 3) Magnesium

Q3. Which micronutrient is required for splitting of water molecules during photosynthesis?

1. Manganese

2. Molybdenum

3. Magnesium

4. Copper

Correct answer: 1) Manganese

Explanation:

Manganese (Mn) is an essential micronutrient for plants, absorbed primarily as Mn²⁺ ions. It serves several important functions, including the activation of enzymes involved in respiration, nitrogen metabolism, and photosynthesis. Its primary role is in the process of photosynthesis, where manganese is a key component of the water-splitting system (specifically in the oxygen-evolving complex of photosystem II). Here, it helps catalyze the splitting of water molecules, releasing oxygen as a byproduct. This makes manganese crucial for maintaining the overall efficiency of photosynthesis and supporting plant growth.

Hence, the correct answer is option 1) Manganese.

Also Read:

• MCQs on Role of Micronutrients

• Difference between Macronutrients And Micronutrients

• Fate of Ammonia

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