Deficiency Symptoms of Essential Elements Questions in English

(A) The deficiency of certain mineral elements can lead to a delay in the flowering process in plants.
Specifically,the deficiency of $N$ (Nitrogen),$S$ (Sulphur),and $Mo$ (Molybdenum) is known to inhibit or delay flowering.
$N$ is a major component of proteins and nucleic acids,$S$ is essential for amino acids like cysteine and methionine,and $Mo$ is a cofactor for enzymes like nitrate reductase.
Therefore,the correct group of elements is Nitrogen,Sulphur,and Molybdenum.

(D) The deficiency of certain essential mineral elements can lead to physiological changes in plants,including the delay of flowering.
Specifically,the deficiency of $N$ (Nitrogen),$S$ (Sulphur),and $Mo$ (Molybdenum) is known to cause a delay in the flowering process in many plant species.
Therefore,all the given options are correct as they all contribute to this specific deficiency symptom.

(A) Necrosis is the localized death of plant tissue,especially in leaves.
It is primarily caused by the deficiency of mineral elements such as $Ca$,$Mg$,$Cu$,and $K$.
Among the given options,$Ca$,$Mg$,and $K$ are well-known elements whose deficiency leads to necrosis in leaves.
Therefore,the correct set of elements is $Ca, Mg, K$.

(C) The root system in plants is highly plastic and responds to the availability of nutrients in the soil. When there is a deficiency of mineral salts (nutrients) in the soil,the plant directs more resources toward root growth to explore a larger volume of soil for nutrient uptake. This is a physiological adaptation to ensure survival under nutrient-limited conditions.

(C) The deficiency symptoms of essential elements in plants include:
$1$. Chlorosis: Loss of chlorophyll leading to yellowing of leaves.
$2$. Necrosis: Death of tissue,particularly leaf tissue.
$3$. Inhibition of cell division: Leading to stunted growth.
$4$. Delay in flowering: If the concentration of essential elements is low.
$5$. Shortening of internodes.
All options $A$,$B$,$C$,and $D$ are recognized deficiency symptoms in $NCERT$ Biology. However,if the question implies selecting the most general term or if there is a discrepancy in the provided options,'Stunting' is a result of the inhibition of cell division. Given the standard $NCERT$ list,all these are valid symptoms. If this is a multiple-choice question where one must be excluded,please note that all listed options are standard deficiency symptoms.

(C) Magnesium is a central component of the chlorophyll molecule. Its deficiency leads to chlorosis,where leaves turn yellow because chlorophyll cannot be synthesized.
Urea is a nitrogen-rich fertilizer. When urea is added to the soil,it provides nitrogen,which promotes vegetative growth and increases chlorophyll synthesis.
However,if the soil remains deficient in magnesium,the plant cannot form functional chlorophyll despite the presence of nitrogen. In many cases,the rapid growth induced by nitrogen without sufficient magnesium exacerbates the chlorosis,causing the leaves to turn yellow more prominently or fail to green up.

(D) The grey spot disease of oats is a well-known physiological disorder caused by the deficiency of Manganese $(Mn)$.
This element is essential for the activation of various enzymes involved in photosynthesis,respiration,and nitrogen metabolism.
When $Mn$ is deficient,the leaves develop characteristic greyish-brown spots,which eventually lead to the necrosis of leaf tissue.

(A) Nitrogen $(N)$ and potassium $(K)$ are mobile elements within the plant.
When a plant experiences a deficiency of these mobile nutrients,they are translocated from older,senescent tissues to younger,actively growing tissues.
Therefore,the deficiency symptoms of mobile elements like $N$,$K$,and $Mg$ first appear in older or senescent leaves.

(A) Vitamin $D$ is essential for the absorption of calcium from the gastrointestinal tract.
In the absence of vitamin $D$,the body cannot effectively absorb calcium from the diet,even if calcium intake is sufficient.
This leads to a deficiency of calcium in the blood and tissues,which can cause conditions like rickets in children and osteomalacia in adults.

(C) The Assertion is correct because sulphur deficiency leads to chlorosis (yellowing of leaves) in plants,particularly in younger leaves.
However,the Reason is incorrect because sulphur is not a constituent of chlorophyll. The central atom of the chlorophyll molecule is magnesium $(Mg^{2+})$.
Sulphur is a component of certain amino acids (like cysteine and methionine),vitamins (like biotin and thiamine),and coenzymes,but it is not part of the chlorophyll structure.

(N/A) The five main deficiency symptoms observed in plants are:
$1$. Chlorosis: This is the loss of chlorophyll leading to the yellowing of leaves. It is caused by the deficiency of $N, K, Mg, S, Fe, Mn, Zn,$ and $Mo$.
$2$. Necrosis: This refers to the death of plant tissues,particularly leaves. It is caused by the deficiency of $Ca, Mg, Cu,$ and $K$.
$3$. Inhibition of cell division: This leads to reduced growth and is caused by the deficiency of $N, K, S,$ and $Mo$.
$4$. Delayed flowering: This occurs when the concentration of essential nutrients is low,specifically due to the deficiency of $N, S,$ and $Mo$.
$5$. Stunted plant growth: This is a general symptom of poor development caused by the deficiency of $Cu$ and $S$.

(B) In plants,the deficiency of a nutrient can cause multiple symptoms. For example,the deficiency of $N$ (nitrogen) causes chlorosis and delayed flowering.
In a similar way,the deficiency of one nutrient can cause the same symptom as that caused by the deficiency of another nutrient. For example,necrosis is caused by the deficiency of $Ca$,$Mg$,$Cu$,and $K$.
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.

(N/A) Deficiency symptoms are morphological changes in plants that indicate nutrient deficiency. The appearance of these symptoms depends on the mobility of the deficient element within the plant.
$1$. Elements that are actively mobilized: Elements such as $N$,$K$,and $Mg$ are highly mobile. They are transported from mature (older) tissues to younger,developing parts of the plant. Consequently,deficiency symptoms for these elements appear first in the older parts.
$2$. Elements that are relatively immobile: Elements such as $Ca$ and $S$ are structural components and are not easily transported out of mature tissues. Therefore,when these elements are deficient,the younger parts of the plant,which are actively growing,show the symptoms first.

(N/A) $\Rightarrow$ Whenever the supply of an essential element becomes limited,plant growth is retarded.
$\Rightarrow$ The concentration of the essential element below which plant growth is retarded is termed as critical concentration.
$\Rightarrow$ The element is said to be deficient when present below the critical concentration.
$\Rightarrow$ Deficiency symptoms: Each element has one or more specific structural or functional roles in plants. In the absence of any particular element,plants show certain morphological changes.
$\Rightarrow$ These morphological changes are indicative of certain element deficiencies and are called deficiency symptoms. The deficiency symptoms vary from element to element and they disappear when the deficient mineral nutrient is provided to the plant.
$\Rightarrow$ However,if deprivation continues,it may eventually lead to the death of the plant.
$\Rightarrow$ The parts of the plant that show the deficiency symptoms also depend on the mobility of the element in the plant.
$\Rightarrow$ Mobilized elements: For elements that are actively mobilized within the plants and exported to young developing tissues,the deficiency symptoms tend to appear first in the older tissues. In older leaves,biomolecules containing these elements are broken down,making these elements available for mobilizing to younger leaves.
$\Rightarrow$ Immobilized elements: The deficiency symptoms tend to appear first in the young tissues whenever the elements are relatively immobile and are not transported out of the mature organs. For example,elements like sulphur and calcium are a part of the structural component of the cell and hence are not easily released.
$\Rightarrow$ This aspect of mineral nutrition of plants is of great significance and importance to agriculture and horticulture.

(N/A) $\Rightarrow$ Chlorosis: It is the loss of chlorophyll leading to the yellowing of leaves. It is caused by the deficiency of $N, K, Mg, S, Fe, Mn, Zn$ and $Mo$.
$\Rightarrow$ Necrosis: It is the death of tissues,particularly leaf tissue. It is caused by the deficiency of $Ca, Mg, Cu$ and $K$.
$\Rightarrow$ Retarded growth of plant: It involves the inhibition of cell division. It is caused by the deficiency of $N, K, S$ and $Mo$.
$\Rightarrow$ Delayed flowering: $A$ low level or lack of $N, S$ and $Mo$ causes delayed flowering in plants.
$\Rightarrow$ Inhibition of cell division: It is caused by the deficiency of $N, K, S, Mo$ and $Cl$.

(N/A) $\Rightarrow$ Chlorosis is the loss of chlorophyll,which leads to the yellowing of leaves.
$\Rightarrow$ This symptom is caused by the deficiency of elements $N, K, Mg, S, Fe, Mn, Zn$,and $Mo$.
$\Rightarrow$ Necrosis refers to the death of tissues,particularly leaf tissue.
$\Rightarrow$ It is caused by the deficiency of $Ca, Mg, Cu$,and $K$.

(A-B) The toxicity of any mineral ion is defined as the concentration of the mineral ion in tissues that reduces the dry weight of tissues by about $10\%$.
Two examples of toxic elements are:
$1$. Manganese $(Mn)$: Its toxicity leads to the appearance of brown spots surrounded by chlorotic veins. It competes with iron $(Fe)$ and magnesium $(Mg)$ for uptake and also inhibits calcium $(Ca)$ translocation to the shoot apex.
$2$. Aluminum $(Al)$: Its toxicity primarily affects root growth by inhibiting cell division in the root tips,leading to a stunted root system and reduced nutrient uptake.

(N/A) $(1)$ Chlorosis: It is the loss of chlorophyll in leaves,which leads to the yellowing of leaf tissue. It is caused by the deficiency of elements like $N, K, Mg, S, Fe, Mn, Zn$ and $Mo$.
$(2)$ Necrosis: It is the localized death of plant tissues,particularly leaf tissue. It is caused by the deficiency of $Ca, Mg, Cu$ and $K$.

(N/A)

Term	Definition
Critical Concentration	The concentration of an essential element in plant tissues below which plant growth is retarded.
Deficient	The concentration of an essential element which is lower than the critical concentration, resulting in specific morphological symptoms and reduced growth.

Regarding the values for $Fe$ and $Zn$ (as per standard plant physiology data):
$1$. Critical concentration for $Zn$ is approximately $20 \text{ } \mu g \text{ } g^{-1}$ of dry weight. Below this, the plant is considered deficient.
$2$. Critical concentration for $Fe$ is approximately $100 \text{ } \mu g \text{ } g^{-1}$ of dry weight. Below this, the plant is considered deficient.
Note: The values provided in the original prompt were incorrect; standard physiological values are measured in $\mu g \text{ } g^{-1}$ (ppm), not percentages.

(A) The deficiency symptoms of elements that are actively mobilized within the plants appear first in the older tissues.
When an element is actively mobilized,the plant transports it from older,mature leaves to younger,developing leaves to support their growth.
As a result,the older leaves become deficient in that specific element,and symptoms manifest there first.
Examples of such mobile elements include nitrogen,potassium,and magnesium.

(A) Elements that are actively mobilized within the plants show deficiency symptoms first in older tissues because they are transported to younger,developing tissues.
$1$. Highly mobile elements: These include $N$,$K$,and $Mg$. Deficiency symptoms appear first in older leaves.
$2$. Relatively immobile elements: These include $Ca$ and $S$. These are structural components and are not released from older tissues,so deficiency symptoms appear first in younger leaves.

(A) The mobility of elements is a crucial concept in plant nutrition. Elements that are actively mobilized within the plant,such as $N$,$P$,$K$,and $Mg$,are transported from older,senescing leaves to younger,developing leaves when their supply is deficient. Consequently,deficiency symptoms for these mobile elements appear first in older leaves. Conversely,elements that are relatively immobile,such as $Ca$ and $S$,do not move from older to younger tissues,so their deficiency symptoms appear first in younger leaves. In agriculture and horticulture,this knowledge allows farmers and gardeners to diagnose nutrient deficiencies by observing which leaves (older vs. younger) are affected,enabling them to apply the correct fertilizers specifically tailored to the plant's needs.

(B) Chlorosis is the loss of chlorophyll,which results in the yellowing of leaves. It is a condition where leaves produce insufficient chlorophyll,often caused by nutrient deficiencies such as $N$,$K$,$Mg$,$Fe$,$S$,$Mn$,$Zn$,and $Mo$.

(D) The deficiency of $Potassium$ $(K)$ in plants leads to a characteristic symptom known as chlorosis or necrosis at the leaf margins.
Specifically,the edges of the leaves turn yellowish and eventually brown or necrotic.
This occurs because $Potassium$ is a mobile element and is translocated from older leaves to younger,growing parts,causing the deficiency symptoms to appear first in older leaves.

(B) The deficiency of $Zinc$ $(Zn)$ leads to the inhibition of plant growth and development. Specifically,it causes the leaves to become distorted,sickle-shaped,and clustered together to form a rosette-like appearance. This characteristic symptom is commonly known as the little leaf disease.

(A) Phosphorus is a vital constituent of nucleic acids,proteins,$NADP^+$,and cell membranes.
Its deficiency leads to poor plant growth,chlorosis (mottled appearance),necrosis,and the premature falling of leaves and flowers.

(A) The deficiency of the micronutrient manganese $(Mn)$ leads to the physiological disorder known as 'grey spots of oat'. This condition is characterized by the appearance of greyish-brown spots on the leaves,which eventually leads to necrosis and reduced crop yield.

(C) Necrosis is a physiological disorder in plants characterized by the localized death of cells or tissues. It is often caused by nutrient deficiencies (such as $Ca$,$Mg$,$Cu$,or $K$),pathogens,or environmental stress. Therefore,the term necrosis refers to the death of plant tissues.

(C) The deficiency of zinc $(Zn)$ is responsible for several physiological disorders in plants,including little leaf,leaf rosettes,interveinal chlorosis,and the specific 'Khaira disease of rice'.
In contrast,the deficiency of molybdenum $(Mo)$ is known to cause 'whiptail disease' and the loosening of inflorescence in cauliflower.

(D) Boron is essential for the translocation of sugars from source to sink in plants.
It plays a critical role in the movement of carbohydrates through the phloem.
$A$ deficiency of boron leads to poor fruit development and a reduction in fruit size.
Therefore,adding boron to the soil helps in improving the translocation of sugars,which in turn increases the size of the fruits.

(A) $Magnesium$ is a central component of the chlorophyll molecule,which is essential for photosynthesis.
It also acts as an important binding substance for ribosomal sub-units.
Its deficiency leads to inter-veinal chlorosis (yellowing of leaves between veins),the development of anthocyanin pigments,and the depression of internal phloem.

(C) Potassium is a macroelement for plants.
Deficiency symptoms of potassium include:
$1$. Mottled inter-veinal chlorosis,which appears first in older leaves.
$2$. Marginal or apical yellowing,scorching,and curling of leaves.
$3$. Die-back,bushy habit,shorter internodes,and loss of apical dominance.
$4$. In cereals,it may lead to lodging.
$5$. Other effects include loss of cambial activity,plastid disintegration,and an increase in the rate of respiration.

(B) Etiolation is a condition that develops in plants when they are grown in the dark,characterized by a lack of chlorophyll,pale yellow or white color,long internodes,small rudimentary leaves,and poor development of lignified tissues. It is caused by the absence of light,not by mineral deficiency. In contrast,chlorosis,necrosis,and the shortening of internodes are classic symptoms of mineral deficiency in plants.

(B) Calcium is involved in the selective permeability of cell membranes.
It activates certain enzymes required for the development of the stem and root apex and is present as calcium pectate in the middle lamella of the cell wall.
The deficiency of calcium causes stunted growth,degeneration of meristems,especially the root apex,chlorosis,necrosis,and curling of leaves.

(A) Nitrogen is a mobile element in plants. When nitrogen is deficient,the plant translocates nitrogen from older,mature leaves to younger,actively growing tissues. Consequently,the deficiency symptoms,such as chlorosis (yellowing),appear first in the older leaves.

(B) Elements that are actively mobilized within the plant show deficiency symptoms first in older tissues because they are transported to younger,developing parts. These include $N, K,$ and $Mg$.
Elements that are structurally immobile (e.g.,$Ca$ and $S$) do not move easily from older tissues to younger ones. Therefore,their deficiency symptoms first appear in young tissues.
Thus,$Calcium$ is the exception.

(A) In plants,mineral elements are classified based on their mobility. Elements that are actively mobilized within the plant move from older tissues to younger developing tissues. Therefore,their deficiency symptoms appear first in older leaves. These include $N$,$P$,$K$,and $Mg$.
Conversely,elements that are relatively immobile,such as $Ca$ and $S$,are structural components of cell walls or proteins and cannot be easily transported from older tissues to younger ones. Consequently,the deficiency symptoms of these immobile elements appear first in the young leaves.

(A) The death of plant tissues,particularly leaf tissues,is known as necrosis.
Necrosis is primarily caused by the deficiency of mineral elements such as $Ca$,$Mg$,$Cu$,and $K$.
Among the given options,$Ca$ and $Mg$ are the elements whose deficiency leads to the death of leaf tissues.
Therefore,the correct option is $A$.

(A) The deficiency of elements such as Nitrogen $(N)$,Potassium $(K)$,Sulfur $(S)$,and Molybdenum $(Mo)$ is known to cause inhibition of cell division in plants.
This leads to stunted growth and chlorosis in the affected plant tissues.

(A) Molybdenum $(Mo)$ is a crucial component of the enzyme nitrate reductase,which is responsible for the reduction of nitrate to ammonia in plants. If nitrate is the primary source of nitrogen,a deficiency in $Mo$ prevents this conversion,leading to nitrogen deficiency symptoms. Additionally,$Mo$ is a component of nitrogenase,an enzyme essential for symbiotic nitrogen fixation in legumes. Therefore,$Mo$ deficiency indirectly causes nitrogen deficiency.

(C) The term 'hunger signs' in plants refers to the visible morphological changes or symptoms that appear due to the deficiency of essential mineral nutrients.
When a plant does not receive adequate amounts of specific minerals,it exhibits characteristic symptoms such as chlorosis,necrosis,stunted growth,or premature leaf fall,which are collectively known as hunger signs.

(A) Manganese toxicity symptoms include the appearance of brown spots surrounded by chlorotic veins.
It also inhibits the translocation of calcium to the shoot apex.
This occurs because manganese competes with iron and magnesium for uptake and with calcium for translocation.
Therefore,manganese toxicity induces the deficiency of $Fe$,$Mg$,and $Ca$.
Both the Assertion and the Reason are correct,and the Reason provides the correct explanation for the symptoms described in the Assertion.

(B) The deficiency of nitrogen $(N)$ in plants leads to chlorosis,which is the yellowing of leaves.
Nitrogen is a major component of chlorophyll,amino acids,and nucleic acids.
Its deficiency results in stunted growth,delayed flowering,and reduced protein synthesis.
While magnesium deficiency also causes chlorosis,the specific symptom of yellowish edges (marginal chlorosis) is most characteristically associated with potassium $(K)$ deficiency,though nitrogen deficiency causes general yellowing of older leaves.

(B) The concentration of an essential element below which plant growth is retarded is known as the $Critical$ $concentration$. If the concentration of an essential element falls below this level,the plant exhibits specific deficiency symptoms.

(A) When an essential element is absent or present in a concentration below the critical concentration,the plant exhibits certain morphological changes. These changes are known as deficiency symptoms. These symptoms vary from element to element and disappear when the deficient mineral nutrient is provided to the plant. Therefore,the correct term is deficiency symptoms.

(D) The deficiency of certain mineral elements like $Nitrogen$, $Sulphur$, and $Molybdenum$ is known to delay the process of flowering in plants.
$Nitrogen$ is a major component of proteins and nucleic acids, essential for growth.
$Sulphur$ is a component of amino acids like $Cysteine$ and $Methionine$.
$Molybdenum$ is essential for nitrogen metabolism.
Therefore, the deficiency of any of these elements can lead to a delay in the transition from vegetative to reproductive phase, resulting in delayed flowering.

(A) Elements that are actively mobilized within the plants,such as Nitrogen $(N)$,Potassium $(K)$,and Magnesium $(Mg)$,show deficiency symptoms first in older (senescent) leaves because they are transported to younger,developing parts.
Elements that are relatively immobile,such as Sulfur $(S)$ and Calcium $(Ca)$,do not get transported out of mature organs; therefore,their deficiency symptoms appear first in young leaves.
Thus,$P$ (young leaves) corresponds to $S$ and $Ca$,and $Q$ (older leaves) corresponds to $N$,$K$,and $Mg$.

(D) The correct matches based on mineral deficiency symptoms are:
$P$. Chlorosis (loss of chlorophyll leading to yellowing of leaves) is caused by the deficiency of $N, K, Mg, S, Fe, Mn, Zn, Mo$. Thus, $P-III$.
$Q$. Necrosis (death of tissue, particularly leaf tissue) is caused by the deficiency of $Ca, Mg, Cu, K$. Thus, $Q-I$.
$R$. Inhibition of cell division is caused by the deficiency of $N, K, S, Mo$. Thus, $R-IV$.
$S$. Delay in flowering is caused by the deficiency of $N, S, Mo$. Thus, $S-II$.
Therefore, the correct sequence is $(P-III), (Q-I), (R-IV), (S-II)$.

(D) In plant physiology, the concentration of essential mineral elements is critical for growth.
$1$. When the concentration of a mineral element falls below a certain level, it is termed as the critical concentration, and the plant shows specific morphological changes known as $\text{Deficiency symptoms}$.
$2$. When the concentration of a mineral element exceeds a certain level, it interferes with the uptake or metabolism of other nutrients, leading to $\text{Toxicity}$.