CBSE Quick Revision Notes (Class-11 Biology)
CHAPTER-12 MINERAL NUTRITION
Mineral nutrition is the study of source, mode of absorption, distribution and metabolism of
various inorganic substances (minerals) by plants for their growth, development, structure,
physiology and reproduction.
Methods to study the Mineral Requirement of Plants
• Hydroponics is the technique of growing plants in nutrient solution in complete absence
of soil. This method is used to determine the nutrients essential for plants.
• In this method plant is cultured in soil-free, defined mineral solution. These methods
require purified water and mineral nutrients.
• Essential elements are identified and their deficiency symptoms are discovered by
hydroponics methods. It is also used to commercial
production of vegetables, like tomato and cucumber.
Essential mineral nutrients- About 65 elements are found
in different plants. Following criteria is used to
determine the essentiality of an element.
a. Element must be absolutely necessary for the normal
growth and reproduction to complete their life cycle.
b. The requirement of element must be specific and not
replaceable.
c. Element must be directly involved in the metabolism of
plants.
• Macronutrients are present in plants
tissues in larger quantity. C,H and O
is obtained from water and rest are
absorbed from soil.
• Micronutrients or trace nutrients are
required in vary small quantity.
On the basis of diverse functions, essential elements are divided into following categories-
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, Role of Macro and Micro nutrients-
(i) Essential elements participate in various metabolic processes in plants such as
permeability of cell membrane, maintenance of osmotic potential, ETS. Etc.
(ii) Act as major constituents of macromolecules and co-enzymes.
Various forms and function of essential nutrients-
a. Nitrogen- required by plants in greatest amount, it is absorbed by plants as NO2-,NO3-and
NH4+ . It is one of the major constituent of proteins, nucleic acids and vitamins.
b. Phosphorus- Absorbed by plants from soil in form of phosphate ions. It is the constituent
of cell membrane, all nucleic acids and nucleotides require phosphorus.
c. Potassium – absorbed as potassium ions (K+). Help to maintain cation-anion balance in
cells. It is involved in protein synthesis, opening and closing of stomata.
d. Calcium – absorbed by plants from soil in form of Calcium ions (Ca2+). Used in synthesis of
cell wall. It activates certain enzymes.
e. Magnesium- absorbed by plants in form of Mg2+ ions. It activates the enzymes for
respiration, photosynthesis, and involved in DNA and RNA. Constituent of chlorophyll.
f. Sulphur- plants obtain sulphur in form of sulphate (SO42-). Present in amino acids
(cysteine, methionine) and is main constituent of coenzymes and vitamins.
g. Iron- obtains in form of ferric iron (Fe3+). It is important constituents of protein involved in
transport system.
h. Manganese- absorbed in form of Mn2+ ions. Main function is splitting of water to liberate
Hydrogen and Oxygen during photosynthesis.
i. Zinc- obtained as Zn2+ ions. Activate enzymes like carboxylases. Needed in formation of
Auxin.
j. Copper – absorbed as cupric ions(Cu2+). Involved in various metabolic activities and redox
reactions.
k. Boron- absorbed as BO33- or B4O7- ions. Required for uptake of calcium, cell elongation and
pollen germination.
l. Chlorine – it is absorbed in form of Cl- ions. Determine the solute concentration and
splitting of water during photosynthesis.
Deficiency Symptoms of Essential elements
When supply of essential elements becomes limited, plant growth is retarded. The
concentration of essential elements below which plant growth is retarded is called critical
concentration.
In absence of any particular element shows certain morphological changes. These
morphological changes are called deficiency symptoms.
The parts of plant that show deficiency symptoms depend upon mobility of elements in the
plants. Elements that are actively mobilized (N,Mg,K) shows deficiency in older regions. On
the other hand, symptoms appear first in young region if the elements are relatively
immobile (Ca) and not transported out of mature tissues.
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CHAPTER-12 MINERAL NUTRITION
Mineral nutrition is the study of source, mode of absorption, distribution and metabolism of
various inorganic substances (minerals) by plants for their growth, development, structure,
physiology and reproduction.
Methods to study the Mineral Requirement of Plants
• Hydroponics is the technique of growing plants in nutrient solution in complete absence
of soil. This method is used to determine the nutrients essential for plants.
• In this method plant is cultured in soil-free, defined mineral solution. These methods
require purified water and mineral nutrients.
• Essential elements are identified and their deficiency symptoms are discovered by
hydroponics methods. It is also used to commercial
production of vegetables, like tomato and cucumber.
Essential mineral nutrients- About 65 elements are found
in different plants. Following criteria is used to
determine the essentiality of an element.
a. Element must be absolutely necessary for the normal
growth and reproduction to complete their life cycle.
b. The requirement of element must be specific and not
replaceable.
c. Element must be directly involved in the metabolism of
plants.
• Macronutrients are present in plants
tissues in larger quantity. C,H and O
is obtained from water and rest are
absorbed from soil.
• Micronutrients or trace nutrients are
required in vary small quantity.
On the basis of diverse functions, essential elements are divided into following categories-
Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks
, Role of Macro and Micro nutrients-
(i) Essential elements participate in various metabolic processes in plants such as
permeability of cell membrane, maintenance of osmotic potential, ETS. Etc.
(ii) Act as major constituents of macromolecules and co-enzymes.
Various forms and function of essential nutrients-
a. Nitrogen- required by plants in greatest amount, it is absorbed by plants as NO2-,NO3-and
NH4+ . It is one of the major constituent of proteins, nucleic acids and vitamins.
b. Phosphorus- Absorbed by plants from soil in form of phosphate ions. It is the constituent
of cell membrane, all nucleic acids and nucleotides require phosphorus.
c. Potassium – absorbed as potassium ions (K+). Help to maintain cation-anion balance in
cells. It is involved in protein synthesis, opening and closing of stomata.
d. Calcium – absorbed by plants from soil in form of Calcium ions (Ca2+). Used in synthesis of
cell wall. It activates certain enzymes.
e. Magnesium- absorbed by plants in form of Mg2+ ions. It activates the enzymes for
respiration, photosynthesis, and involved in DNA and RNA. Constituent of chlorophyll.
f. Sulphur- plants obtain sulphur in form of sulphate (SO42-). Present in amino acids
(cysteine, methionine) and is main constituent of coenzymes and vitamins.
g. Iron- obtains in form of ferric iron (Fe3+). It is important constituents of protein involved in
transport system.
h. Manganese- absorbed in form of Mn2+ ions. Main function is splitting of water to liberate
Hydrogen and Oxygen during photosynthesis.
i. Zinc- obtained as Zn2+ ions. Activate enzymes like carboxylases. Needed in formation of
Auxin.
j. Copper – absorbed as cupric ions(Cu2+). Involved in various metabolic activities and redox
reactions.
k. Boron- absorbed as BO33- or B4O7- ions. Required for uptake of calcium, cell elongation and
pollen germination.
l. Chlorine – it is absorbed in form of Cl- ions. Determine the solute concentration and
splitting of water during photosynthesis.
Deficiency Symptoms of Essential elements
When supply of essential elements becomes limited, plant growth is retarded. The
concentration of essential elements below which plant growth is retarded is called critical
concentration.
In absence of any particular element shows certain morphological changes. These
morphological changes are called deficiency symptoms.
The parts of plant that show deficiency symptoms depend upon mobility of elements in the
plants. Elements that are actively mobilized (N,Mg,K) shows deficiency in older regions. On
the other hand, symptoms appear first in young region if the elements are relatively
immobile (Ca) and not transported out of mature tissues.
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