Content Curator
Micronutrients are nutrients that are required in lesser amounts for the growth & development of the body and play a major role in the metabolic activities of the body e.g. vitamins and minerals. Micronutrients are required in less quantity in our bodies than macronutrients and this is how the differentiation between micromineral and macromineral is made. The macronutrients form an integral part of the metabolism whereas most micronutrients aid metabolism.
| Table of Content |
Key Terms: Micronutrients, micronutrients in plants, deficiency of micronutrients, minerals, vitamins, nutrients, macrominerals
Micronutrients in Plants
[Click Here for Sample Questions]
There are seven main micronutrients required by plants, some nutrients control the permeability of a cell membrane, and some other control the osmotic pressure, etc.
Boron (B), Zinc (Zn), Manganese (Mn), Iron (Fe), Copper (Cu), Molybdenum (Mo), and Chlorine (Cl) are some of the important micronutrients required by the plants, lack of any of these nutrients affects growth and development.
Micronutrients in Plants
Boron (B)
Boron plays an important role in blossoming, ripening, cell division, and pollen germination. Boron is found in tourmaline and is a highly insoluble mineral. It is essential for the proper development and strengthening of the cell wall. A deficiency that results in reduced seed and grain production. Boron deficiencies generally occur during drought periods, whereas, excess supply or availability of boron is also harmful to the plant.
Zinc (Zn)
Zinc is an essential element that helps in photosynthesis, producing energy, and regulating growth. Its deficiency may cause slower maturity and reduction in the size of the leaf and these deficiencies often occur during the cold, wet spring season.
Manganese (Mn)
Manganese is crucial for photosynthesis and nitrogen metabolism. Early leaf drop and delayed maturity are the symptoms of its deficiency. Manganese is ample in wet soils, whereas dry soil has limited manganese.
Iron (Fe)
Iron is essential for energy transmission, nitrogen fixation, and reduction. Iron, along with sulfur, acts as a catalyst in the formation of various reactions. Yellow colored leaves are the symptom of Iron deficiency.
Copper (Cu)
Copper is vital for proper functioning, photosynthesis, grain production, and the strengthening of a cell wall. Stunted growth and yellow-colored leaves are the symptoms of copper deficiency.
Molybdenum (Mo)
Molybdenum is required for pollen formation and nitrogen fixation. Reduced fruit or grain growth are the symptoms of Molybdenum deficiency. Sandy soils in humid region are the places where zinc deficiencies are found.
Chlorine (Cl)
Chlorine is the nutrient that helps in osmosis and ionic equilibrium. It also plays a key role in the process of photosynthesis. Decreased resistance and, reduced plant growth are the symptoms of chlorine deficiency.
Also check:
| Important Concepts | ||
|---|---|---|
| Osmotic Pressure Equation | Seed Germination | Nodule Formation |
| Rhizobium | Sulphur Cycle | Mineral Nutrition |
| Nitrogen Cycle | Denitrification | Ammonification |
Deficiency of Micronutrients in Plants
[Click Here for Previous Year Questions]
Following are the symptoms that mark the deficiency of micronutrients in plants:
| Micronutrient | Deficiency Symptoms |
|---|---|
| Boron | Chlorosis, leaf deformation with patches of discoloration |
| Chlorine | Chlorosis, wilting of leaves |
| Copper | Overall chlorosis, twisting of leaf tips, turgor loss in young leaves |
| Iron | Chlorosis between the veins of the new leaves |
| Molybdenum | Chlorosis of oldest leaves |
| Manganese | Chlorosis between the veins of the new leaves |
| Zinc | Reduced growth of young leaves than normal |
Trace Minerals
[Click Here for Sample Questions]
These are required in very small amounts but perform various vital functions in our body. Iron, manganese, copper, zinc, iodine, fluoride, and selenium are a few of the important trace minerals required by the body.
Macrominerals
[Click Here for Previous Year Questions]
These are required in higher amounts as compared to trace minerals, important macrominerals and their functions include:
- Calcium- For the proper structure and function of bones.
- Phosphorus – Cell membrane structure
- Magnesium- Enzyme reactions
- Sodium- Fluid balance and maintenance of blood pressure
- Chloride- Maintains fluid balance and formation of digestive juices.
- Potassium- Nerve impulse transmission and muscle function.
- Sulphur- present in all the living tissues
Previous Year Questions
- Mg is a component of… [NEET 2000]
- A plant requires magnesium for… [NEET 2007]
- A prokaryotic autotrophic nitrogen fixing symbiont is found in… [NEET 2011]
- A system of rotating crops with legume or grass pasture to improve soil… [NEET 2016]
- Best defined function of manganese in green plants is… [NEET 2012]
- Boron in green plants assists in… [NEET 2003]
- Deficiency symptoms of nitrogen and potassium are visible first in… [NEET 2014]
- For its activity, carboxypeptidase requires… [NEET 2012]
- Gray spots of oat are caused by deficiency of… [NEET 2003]
- If by radiation all nitrogenase enzyme is inactivated… [NEET 2004]
- In which of the following forms is iron absorbed by plants… [NEET 2018]
- Leguminous plants are able to fix atmospheric nitrogen through… [NEET 2010]
- The deficiencies of micronutrients, not only affects growth of plants but also… [NEET 2005]
- What is true for cyanobacteria… [NEET 2001]
- Which is essential for the growth of root tip… [NEET 2016]
- Which of the following can fix atmospheric nitrogen… [NEET 1995]
- Which of the following elements is responsible for maintaining turgor in cells… [NEET 2018]
- Which one of the following elements is not an essential micro-nutrient for… [NEET 2007]
- Which one of the following elements is almost… [NEET 1996]
- Which one of the following is a micronutrient for plants… [NEET 1996]
Things to Remember
- Micronutrients are the elements required by us in small quantities.
- Iron, cobalt, chromium, iodine, copper, zinc, and molybdenum are some of the micronutrients.
- Deficiency of any of the nutrients affects growth and development.
- Micronutrients in plants are beneficial for the balanced nutrition of crops. These support all the biological functions of a plant.
- Their deficiency leads to stunted growth, chlorosis, necrosis, delayed maturity, and senescence.
- The micronutrients in plants bind actively to the soil particles and are highly soluble under acidic conditions.
Also check:
Sample Questions
Ques. Do plants need vitamins? (3 Marks)
Ans. Plants do not have any requirements for vitamins like animals. Their only requirement of micronutrients is minerals like boron, zinc, manganese, sulfur, iron, copper, and calcium. These minerals help in the necessary activities of the plants like cell division, cell wall strengthening, reproduction, flowering, fruiting, etc. Plants produce vitamins for secondary functions like making the fruit more nutritious; this helps the plant in acquiring an important place in the food chain and assures survival for itself.
Ques. What is the source of micronutrients for plants? (2 Marks)
Ans. In relatively large amounts, the soil supplies nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur; these are often called macronutrients. In relatively small amounts, the soil supplies iron, manganese, boron, molybdenum, copper, zinc, chlorine, and cobalt, the so-called micronutrients.
Ques. How are micronutrients absorbed in plants? (2 Marks)
Ans. This process is mediated by root hairs, which are extensions of the root epidermal tissue that increase the surface area of the root, greatly contributing to the absorption of water and minerals. Root hairs absorb ions that are dissolved in the water in the soil.
Ques. How many micronutrients are required by plants? (2 Marks)
Ans. By comparison, corn and soybeans remove about 50 to 100 lbs/acre of P and K in the grain, so it is apparent that micronutrient needs are only about 0.1% to 1% of macronutrient needs (except for iron, which is higher.)
Ques. What is the difference between macronutrients and micronutrients? (2 Marks)
Ans. Macronutrients are the nutrients required by our body in large amounts. Examples include carbohydrates, proteins, fats, antioxidants, fiber, and water. On the contrary, micronutrients are the nutrients required by our body in small amounts. Vitamins and minerals are considered micronutrients.
Ques. Why do plants need only a small amount of micronutrients? (2 Marks)
Ans. Micronutrients are essential elements needed for crop growth that are required in relatively small quantities. Even though demands for micronutrients are small in quantity, these nutrients directly affect crop growth and development.
Ques. How are micronutrients used? (2 Marks)
Ans. Micronutrients can be tank mixed with liquid fertilizers and pesticides to increase efficacy and reduce chemical reactions between nutrients and other components in the tank. Typically, both root and foliar uptake is strong. After spraying with chelated micronutrients, crops can take them up quite quickly.
Ques. How do micronutrients affect plant growth? (2 Marks)
Ans. Micronutrients are essential to plant nutrients that are found in trace amounts in tissue, but play an imperative role in plant growth and development. Without these nutrients, plant nutrition would be compromised leading to potential declines in plant productivity.
Ques. What is the source of micronutrients for plants? (2 Marks)
Ans. In relatively large amounts, the soil supplies nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur; these are often called macronutrients. In relatively small amounts, the soil supplies iron, manganese, boron, molybdenum, copper, zinc, chlorine, and cobalt, the so-called micronutrients.
Ques. What Are The Common Forms Of Micronutrient Deficiency In Humans? (3 Marks)
Ans. Micronutrients are an important form of our daily consumption; their deficiency can lead to many types of adverse effects on the body. Anemia is caused by iron deficiency. Similarly, goiter and mental retardation are caused by a lack of iodine. Vitamin D hypovitaminosis lead to loss of bone density and rickets. Lacking B complex vitamins can lead to muscle weakness. A deficiency of calcium can cause osteoporosis. Lack of vitamin A can cause night blindness. And magnesium deficiency is known to cause muscles cramp and fatigue.
Also check:
Comments