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10/25/2018----Biology Class 11 NCERT Solutions: Chapter 12 Mineral Nutrition Part 1- Translation in Hindi, Kannada, Malayalam, Marathi, Punjabi,, Sindhi, Sindhi, Tamil, Telgu - FlexiPrep----Downloaded from flexiprep.com, Visit examrace.com for free study material, doorsteptutor.com for questions with detailed explanations, and "Examrace" YouTube channel for free, videos lectures, , Flexiprep, ▶, , Examrace 339K, , Biology Class 11 NCERT Solutions: Chapter 12 Mineral Nutrition, Part 1, Q: 1. 'All elements that are present in a plant need not be essential to its survival'. Comment., Answer:, Plants tend to absorb different kinds of nutrients from soil. However, a nutrient is inessential for, a plant if it is not involved in the plant's physiology and metabolism. For example, plants, growing near radioactive sites tend to accumulate radioactive metals. Similarly, gold and, selenium get accumulated in plants growing near mining sites. However, this does not mean that, radioactive metals, gold, or selenium are essential nutrients for the survival of these plants., Q: 2. Why is purification of water and nutrient salts so important in studies involving mineral, nutrition using hydroponics?, Answer:, Hydroponics is the art of growing plants in a nutrient solution in the absence of soil. Since the, plant roots are exposed to a limited amount of the solution, there are chances that the, concentrations of oxygen and other minerals in the plant roots would reduce. Therefore, in, studies involving mineral nutrition using hydroponics, purification of water and nutrient salts is, essential so as to maintain an optimum growth of the plants., , Image Shows the Hydroponics, , Q: 3. Explain with examples: macronutrients, micronutrients, beneficial nutrients, toxic, elements and essential elements., Answer:, 1 of 4
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10/25/2018----Biology Class 11 NCERT Solutions: Chapter 12 Mineral Nutrition Part 1- Translation in Hindi, Kannada, Malayalam, Marathi, Punjabi,, Sindhi, Sindhi, Tamil, Telgu - FlexiPrep----Downloaded from flexiprep.com, Visit examrace.com for free study material, doorsteptutor.com for questions with detailed explanations, and "Examrace" YouTube channel for free, videos lectures, , Macronutrients: They are the nutrients required by plants in large amounts. They are present in, plant tissues in amounts more than, of dry matter. Examples include hydrogen,, oxygen, and nitrogen., Micronutrients: They are also called trace elements and are present in plant bodies in very small, amounts, i.e., amounts less than, of dry matter. Examples include cobalt,, manganese, zinc, etc., , Image of the Macronutrients and Micronutrients, , Beneficial nutrients: They are plant nutrients that may not be essential, but are beneficial to, plants. Sodium, silicon, cobalt, and selenium are beneficial to higher plants., Toxic elements: Micronutrients are required by plants in small quantities. An excess of these, nutrients may induce toxicity in plants. For example, when manganese is present in large, amounts, it induces deficiencies of iron, magnesium, and calcium by interfering with their, metabolism., Essential elements: These elements are absolutely necessary for plant growth and reproduction., The requirement of these elements is specific and non-replaceable. They are further classified as, macro and micronutrients., , 2 of 4
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10/25/2018----Biology Class 11 NCERT Solutions: Chapter 12 Mineral Nutrition Part 1- Translation in Hindi, Kannada, Malayalam, Marathi, Punjabi,, Sindhi, Sindhi, Tamil, Telgu - FlexiPrep----Downloaded from flexiprep.com, Visit examrace.com for free study material, doorsteptutor.com for questions with detailed explanations, and "Examrace" YouTube channel for free, videos lectures, , Q: 4. Name at least five different deficiency symptoms in plants. Describe them and correlate, them with the concerned mineral deficiency., Answer:, The five main deficiency symptoms arising in plants are:, , Five Main Deficiency Symptoms Arising in Plants, , Chlorosis or loss of chlorophyll leads to the yellowing of leaves. It is caused by the deficiencies of, nitrogen, potassium, magnesium, sulphur, iron, manganese, zinc, and molybdenum., Necrosis is the death of plant tissues as a result of the deficiencies of calcium, magnesium,, copper, and potassium., Inhibition of cell division is caused by the deficiencies of nitrogen, potassium, sulphur, and, molybdenum., Delayed flowering is caused by the deficiencies of nitrogen, sulphur, and molybdenum., Stunted plant growth is a result of the deficiencies of copper and sulphur., Q: 5. If a plant shows a symptom which could develop due to deficiency of more than one, nutrient, how would you find out experimentally, the real deficient mineral element?, Answer:, In plants, the deficiency of a nutrient can cause multiple symptoms. For example, the deficiency, of nitrogen causes chlorosis and delayed flowering. In a similar way, the deficiency of a nutrient, can cause the same symptom as that caused by the deficiency of another nutrient. For example,, necrosis is caused by the deficiency of calcium, magnesium, copper, and potassium., , 3 of 4
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10/25/2018----Biology Class 11 NCERT Solutions: Chapter 12 Mineral Nutrition Part 1- Translation in Hindi, Kannada, Malayalam, Marathi, Punjabi,, Sindhi, Sindhi, Tamil, Telgu - FlexiPrep----Downloaded from flexiprep.com, Visit examrace.com for free study material, doorsteptutor.com for questions with detailed explanations, and "Examrace" YouTube channel for free, videos lectures, , Another point to be considered is that different plants respond in different ways to the deficiency, of the same nutrient., Hence, to identify the nutrient deficient in a plant, all the symptoms developed in its different, parts must be studied and compared with the available standard tables., Q: 6. Why is that in certain plants deficiency symptoms appear first in younger parts of the plant, while in others they do so in mature organs?, Answer:, Deficiency symptoms are morphological changes in plants, indicating nutrient deficiency., Deficiency symptoms vary from one element to another. The plant part in which a deficiency, symptom occurs depends on the mobility of the deficient element in the plant. Elements such as, nitrogen, potassium, and magnesium are highly mobile. These elements move from the mature, organs to the younger parts of a plant. Therefore, the symptoms for the deficiencies of these, elements first appear in the older parts of the plant. Elements such as calcium and sulphur are, relatively immobile. These elements are not transported out of the older parts of a plant., Therefore, the symptoms for the deficiencies of these elements first appear in the younger parts, of the plant., Q: 7. How are the minerals absorbed by the plants?, Answer:, The absorption of soil nutrients by the roots of plants occurs in two main phases - apoplast and, symplast., During the initial phase or apoplast, there is a rapid uptake of nutrients from the soil into the, free spaces of plant cells. This process is passive and it usually occurs through trans-membrane, proteins and ion-channels., In the second phase or symplast, the ions are taken slowly into the inner spaces of the cells. This, pathway generally involves the expenditure of energy in the form of ATP., , 4 of 4
