{"id":120258,"date":"2022-05-09T15:57:10","date_gmt":"2022-05-09T10:27:10","guid":{"rendered":"https:\/\/www.mapsofindia.com\/my-india\/?p=120258"},"modified":"2022-05-09T15:57:10","modified_gmt":"2022-05-09T10:27:10","slug":"chapter-12-mineral-nutrition-questions-and-answers-ncert-solutions-for-class-11-biology","status":"publish","type":"post","link":"https:\/\/www.mapsofindia.com\/my-india\/education\/chapter-12-mineral-nutrition-questions-and-answers-ncert-solutions-for-class-11-biology","title":{"rendered":"Chapter 12 – Mineral Nutrition Questions and Answers: NCERT Solutions for Class 11 Biology"},"content":{"rendered":"

1. \u2018All elements that are present in a plant need not be essential to its survival\u2019. Comment<\/h2>\n

Solution:
\nNo, out of 105 elements absorbed by plants only about 17 elements are essential for plant growth and survival.<\/h3>\n

2. Why is purification of water and nutrient salts so important in studies involving mineral nutrition using hydroponics?<\/h2>\n

Solution:
\nHydroponics is a method of growing plants in the nutrition solution in the absence of soil. There are plenty of impurities in impure water in the form of soluble minerals that are dissolved in it. If this water is used as a solution culture to grow plants in hydroponics, these impurities will interfere with the experimental procesdure used to detect the elements. Hence, pure water and purified nutrient salts are utilized in studies involving mineral nutrition using hydroponics.<\/h3>\n

3. Explain with examples: macronutrients, micronutrients, beneficial nutrients, toxic elements and essential elements.<\/h2>\n

Solution:
\nMacronutrients \u2013 Nutrients present in more than 10mmole kg-1of dry matter in plant tissues are known as macronutrients. They are required in large amounts for plant growth. Ex: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulphur, Potassium, calcium and magnesium.
\nMicronutrients \u2013 are the trace elements present in less than 10mmole kg-1of dry matter in plant. Example \u2013 manganese, copper, zinc, boron, nickel
\nBeneficial elements \u2013 In addition to 17essential nutrients there are some beneficial elements required by higher plants in addition to micro and macronutrients. Ex: Sodium, Silicon, Cobalt and selenium.
\nToxic elements are those which are required in trace amount. Their deficiency causes diseases in plants and excess in such nutrients are toxic to plants. Ex: Sodium, Potassium, Magnesium .
\nEssential elements \u2013 It is an element that directly interferes in the metabolism of the plant causing a specific deficiency symptom if not available to plants from an external source.<\/h3>\n

4. Name at least five different deficiency symptoms in plants. Describe them and correlate them with the concerned mineral deficiency.<\/h2>\n

Solution:
\nChlorosis: Loss of chlorophyll leading to the yellow colouration of the leaves. It is caused by the deficiency of N,
\nK, Mg, S, Fe, Mn, Zn and Mo.
\nNecrosis: It is the death of leaf tissue due to deficiency of Ca, Mag, Cu,K. It is the killing of cells expressed in the form of leaf spots, rots and blights.
\nInhibition of cell division: deficiency in Mo, N, K and S causes inhibition of Cell division. They are expressed in stunted growth
\nDelay in flowering: In some plants it is caused due to low concentration of N, S and Mo.
\nDeformation \u2013 It is caused due to deficiency of boron. Deformation, disorganization, discolouration of the meristematic tissue and ultimately death of a growing plant.<\/h3>\n

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?<\/h2>\n

Solution:
\nPlants which show symptoms of multiple nutrient deficieny grown in different sets in water culture. Set 1 , 2 and 3 are given three different nutrients and are grown in hydroponics by supplementing one of the different nutrients showing deficiency. If real deficient element is supplemented then the plant will grow normally without showing deficiency symptoms.<\/h3>\n

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?<\/h2>\n

Solution:
\nMobility of a deficient element decides the appearance of symptoms. If the element is relatively immobile then symptoms appear in young parts and if the deficient element is mobile, then symptoms appear in older parts of the plant.<\/h3>\n

7. How are the minerals absorbed by the plants?<\/h2>\n

Solution:
\nThe process of absorption can be established in two main phases. In the first phase, an initial rapid uptake of ions occurs passively into the \u2018free space\u2019 or \u2018outer space\u2019 of cells \u2013 the apoplast. In the second phase of uptake, the ions are taken in slowly into the symplast of the cells -\u2018inner space\u2019 . The passive movement of ions into the apoplast usually takes place through ion-channels, the trans-membrane proteins that function as selective pores. The entry or exit of ions to and from the symplast requires the expenditure of metabolic energy and that is an active process. The movement of ions is usually called flux; the inward movement into the cells is influx and the outward movement, efflux.<\/h3>\n

8. What are the conditions necessary for fixation of atmospheric nitrogen by Rhizobium? What is their role in N2 -fixation?<\/h2>\n

Solution:
\nFollowing conditions are necessary for fixation of Nitrogen by Rhizobium.
\nSymbiotic relationship between Rhizobium and roots- necessary for the formation of root nodules.
\nNecessity of a reducing environment
\nNitrogenase enzyme \u2013 synthesizes ammonia
\nATP- is required for the synthesis of ammonia
\nNAD(P) H2 or FMNH2 is a source of reducing power
\nFerredoxin \u2013 acts as an electron donor
\nKeto acids picks up amino group.
\nnitrate as a substrate \u2013 creates reduced availability of nitrate
\nRole of Rhizobium in N2 fixation:
\nThey fix atmospheric nitrogen in a form that can be used by plants i.e., ammonia, using the nitrogenase enzyme.
\nPlant, in turn, deliveries bacteria with proteins, carbohydrates and enough oxygen so that they do not disturb the fixation process.
\nA plant protein \u2013 Leghaemoglobin assists in providing oxygen for respiration process while free oxygen concentration level is still low enough to not hinder the nitrogenase activity.<\/h3>\n

\"\"<\/p>\n

9. What are the steps involved in formation of a root nodule?<\/h2>\n

Solution:
\nFormation of nodules involves following steps:
\nRhizobia colonise the roots and get attached to epidermal and root hair cells.
\nBacteria invade the root hair and make it curled.
\nCurling produces an infection thread which carries bacteria into the cortex of the root.
\nRoots nodules are formed at the cortex of the root.
\nWhen infected thread carries the bacteris to the inner cortex, it modifies the bacteria into rod-shaped bacteroids . It causes inner cortical and pericycle cells to undergo division. The division and growth of cortical and pericycle cells result in nodule formation
\nThe vascular tissue continues with that of the root, then a mature nodule is complete<\/h3>\n

\"\"<\/p>\n

10. Which of the following statements are true? If false, correct them:
\n(a) Boron deficiency leads to stout axis.
\n(b) Every mineral element that is present in a cell is needed by the cell.
\n(c) Nitrogen as a nutrient element is highly immobile in the plants.
\n(d) It is very easy to establish the essentiality of micronutrients because they are required only in trace quantities.<\/h2>\n

Solution:
\na) True
\nb) False- Every mineral element that is present in a cell is not needed by the cell.
\nc) False- Nitrogen as a nutrient is highly mobile in plants.
\nd) False- It is challenging to establish the essentiality of micronutrients because they are required only in trace quantities.<\/h3>\n","protected":false},"excerpt":{"rendered":"

Class 11 Biology NCERT book solutions for Chapter 12 – Mineral Nutrition Questions and Answers.<\/p>\n","protected":false},"author":21830,"featured_media":120091,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":{"0":"post-120258","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-education"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts\/120258","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/users\/21830"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/comments?post=120258"}],"version-history":[{"count":1,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts\/120258\/revisions"}],"predecessor-version":[{"id":120261,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts\/120258\/revisions\/120261"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/media\/120091"}],"wp:attachment":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/media?parent=120258"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/categories?post=120258"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/tags?post=120258"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}