Deficiency Symptoms of Essential Elements Questions in English

(B) $Necrosis$ is the localized death of cells or tissues in a living organism,which often leads to discoloration and decomposition of the affected area. It is a common symptom of mineral deficiency in plants.

(C) $Etiolation$ is a phenomenon observed in plants grown in the absence of light (darkness). It is characterized by long, weak stems, smaller leaves, and a pale yellow or white appearance due to the lack of chlorophyll. It is not caused by mineral deficiency, whereas $Necrosis$, $Chlorosis$, and $Shortening$ \text{ of internodes} are well-known symptoms of mineral nutrient deficiencies.

(B) $Calcium$ is essential for the formation of the middle lamella in the form of $Calcium$ pectate, which is necessary for cell wall synthesis. It is also involved in the selective permeability of cell membranes and the activation of various enzymes. Since $Calcium$ is relatively immobile in plants, its deficiency first affects the meristematic tissues, leading to the death of stem and root tips.

(D) The correct answer is $(d)$.
Necrosis,or the death of plant tissues,is a common symptom caused by the deficiency of mineral elements such as $P, K, Ca$ and $Mg$.
This condition typically manifests as the appearance of dead necrotic areas on leaves,often starting at the tips or margins.
Necrosis usually occurs following chlorosis (the loss of chlorophyll) and is a clear indicator of nutrient stress in the plant.

(D) Chlorosis is the loss of chlorophyll leading to the yellowing of leaves.
It is primarily caused by the deficiency of essential mineral elements such as $Mg, Fe, N, Ca,$ and $S$.
Therefore,when plants are grown in a medium lacking these essential nutrients,particularly iron $(Fe)$ or magnesium $(Mg)$,they exhibit chlorosis.

(D) The deficiency of $Calcium$ $(Ca^{2+})$ leads to the weakening of the pedicel and petiole. $Calcium$ is essential for the formation of the middle lamella in the cell wall, which acts as a cementing material between adjacent cells. When $Calcium$ is deficient, the cell walls become weak, leading to the structural instability of plant parts like the pedicel (flower stalk) and petiole (leaf stalk).

(D) The yellowing of tea leaves,often referred to as 'tea yellows',is primarily caused by a deficiency of sulphur. Sulphur is an essential component of amino acids like cysteine and methionine,and it is crucial for the synthesis of chlorophyll. $A$ deficiency leads to reduced meristematic activity and chlorosis (yellowing) of the leaves.

(C) $Mg^{++}$ ions are a central component of the porphyrin ring in the chlorophyll molecule.
When magnesium is deficient,the synthesis of chlorophyll is inhibited,leading to the yellowing of leaves,a condition known as chlorosis.
Therefore,the absence of $Mg^{++}$ ions primarily results in chlorosis.

(D) The correct answer is $D$.
Phosphorus is an essential macronutrient for plants.
Its deficiency leads to several symptoms,including the premature fall of leaves.
Additionally,leaves affected by phosphorus deficiency often exhibit a dark green or blue-green coloration.

(A) $Calcium$ is required by meristematic and differentiating tissues. During cell division, it is used in the synthesis of the cell wall, particularly as $calcium$ $pectate$ in the middle lamella. It is also needed for the normal functioning of the cell membranes. Because $calcium$ is not re-translocated from older tissues to younger, actively growing regions (like root and shoot tips), its deficiency leads to the rapid deterioration and death of these meristematic tips, thereby halting the growth of the plant.

(D) Interveinal chlorosis is a condition where the leaf tissue between the veins turns yellow while the veins remain green.
Magnesium $(Mg^{2+})$ is a central component of the chlorophyll molecule,which is essential for photosynthesis.
When magnesium is deficient,the plant cannot synthesize sufficient chlorophyll,leading to chlorosis,particularly in older leaves where magnesium is mobile and translocated to younger tissues.
Therefore,the deficiency of magnesium is the primary cause of interveinal chlorosis.

(C) The deficiency of $Potassium$ $(K)$ primarily affects the leaves of the plant.
In the early stages of $Potassium$ deficiency,the tips of the leaves become scorched (brown/necrotic).
As the deficiency progresses,the margins (edges) of the leaves turn a dull yellow color,a condition often referred to as marginal chlorosis.
Therefore,the appearance of yellow edges to leaves is a characteristic symptom of $Potassium$ deficiency.

(D) The deficiency of molybdenum $(Mo)$ leads to mottled chlorosis,which is characterized by the yellowing of leaves in patches.
This is accompanied by marginal necrosis (death of leaf tissue) and the infolding of leaves.
In many plants,such as cauliflower,it causes the 'whiptail' disease,where the leaf lamina becomes narrow and twisted due to the failure of the leaf blade to develop properly.

(C) The deficiency of the micronutrient $Boron$ leads to the death of actively dividing cells in plants.
This deficiency causes the breakdown of internal tissues and necrosis of various plant parts.
In cauliflowers,this manifests as the browning of the curd,while in other plants,it may cause symptoms like stem cracking in celery.

(D) The physiological disorder known as internal cork in apple fruit is caused by the deficiency of the micronutrient Boron $(B)$.
Boron deficiency leads to the breakdown of cell walls and the death of internal tissues,resulting in corky spots within the fruit flesh.
Other symptoms of Boron deficiency include top rot of tobacco and heart rot of sugar beet.
These conditions can be corrected by applying small doses of sodium tetraborate (borax) to the soil.

(D) The 'top rot' or 'die-back' of tobacco is a characteristic symptom caused by the deficiency of the micronutrient $Boron$.
Boron is essential for cell division,cell elongation,and the translocation of sugars.
When $Boron$ is deficient,the terminal buds or the apical meristematic tissues die,leading to the 'top rot' condition.

(C) Mottle leaf,also known as little leaf disease,is a characteristic deficiency symptom in citrus plants.
It is caused by the deficiency of the micronutrient $Zinc$ $(Zn)$.
$Zinc$ is essential for the synthesis of the plant hormone auxin,which regulates leaf growth.
When $Zinc$ is deficient,the leaves become smaller,mottled,and show chlorosis,leading to the characteristic 'mottle leaf' appearance.

(C) The deficiency of molybdenum $(Mo)$ causes 'whiptail disease' in cauliflower and cabbage.
In this condition,the leaves first show interveinal mottling,and the leaf margins may become gray and flaccid,eventually turning brown and necrotic.

(A) Manganese is an essential micronutrient for plants.
When plants suffer from manganese deficiency,it is typically corrected by applying manganese in a soluble form that the plant roots can easily absorb.
Manganese sulphate $(MnSO_4)$ is the most commonly used fertilizer to treat manganese deficiency because it is highly soluble in water and provides manganese in the $Mn^{2+}$ ion form,which is the form readily taken up by plants.

(B) The 'petiole crack' or 'cracked stem' disorder in plants,particularly in celery,is a well-documented physiological disorder caused by the deficiency of the micronutrient $Boron$.
Boron plays a crucial role in cell wall synthesis,cell division,and the structural integrity of plant tissues.
$A$ deficiency in $Boron$ leads to the breakdown of cell walls in the petiole,resulting in the characteristic cracking or splitting of the stem.

(D) The browning of cauliflower is a physiological disorder caused by the deficiency of the micronutrient $Boron$.
Boron is essential for cell wall formation,membrane function,and reproductive growth in plants.
In cauliflower,a lack of $Boron$ leads to the development of water-soaked,brown areas on the curd,which is commonly referred to as 'browning' or 'hollow stem'.

(D) The deficiency of $Zinc$ $(Zn)$ in plants leads to the inhibition of the synthesis of auxin (indole$-3-$acetic acid),which is a growth hormone.
This deficiency causes the leaves to become distorted,sickle-shaped,and clustered together to form rosettes.
This specific physiological disorder is known as $little leaf disease$.

(B) The deficiency of $Phosphorus$ $(P)$ in plants leads to several physiological symptoms,including the premature fall of leaves. $Phosphorus$ is a mobile element in plants,and its deficiency often results in stunted growth,dark green or purple discoloration of leaves,and the shedding of immature leaves.

(B) Iron $(Fe)$ is an essential micronutrient required for the synthesis of chlorophyll and the functioning of various enzymes.
Because iron is relatively immobile within the plant,its deficiency symptoms appear first on younger leaves.
Iron deficiency leads to interveinal chlorosis,where the tissue between the veins turns yellow or white while the veins remain green.
This condition is distinct from magnesium deficiency,which typically affects older leaves first.

(C) Heart rot in marigold is a physiological disorder caused by the deficiency of the micronutrient Boron $(B)$.
Boron plays a crucial role in cell wall formation,cell division,and the translocation of sugars within the plant.
Symptoms of boron deficiency often include the death of the growing point (meristem) and the development of necrotic tissues in the center of the plant,commonly referred to as 'heart rot'.
This condition can be effectively corrected or prevented by the application of small doses of sodium tetraborate (borax) to the soil.

(A) The die-back disease in $Citrus$ plants is a classic symptom of Copper $(Cu)$ deficiency.
Copper is an essential micronutrient that plays a vital role in various physiological processes,including photosynthesis and respiration.
Deficiency of Copper leads to the necrosis of the tips of young leaves and the dying back of branches,a condition commonly referred to as 'die-back'.
Since this is a nutritional deficiency and not a fungal infection,the application of fungicides is ineffective.

(D) The "Gray speck disease" in oats is caused by the deficiency of the micronutrient manganese $(Mn)$.
This deficiency leads to the development of gray-brown spots on the leaves, which can eventually cause the total failure of the crop.

(A) Nitrogen is a primary macronutrient essential for plant growth. It is a major component of amino acids,proteins,nucleic acids,and chlorophyll. $A$ deficiency of nitrogen leads to chlorosis (yellowing of leaves),stunted growth,and a significant reduction in the overall growth and size of leaves.

(D) Boron is an essential micronutrient required by plants in very small quantities.
Its primary physiological role involves carbohydrate translocation,pollen germination,and cell wall development.
Specifically,a deficiency of Boron inhibits the cell division of the cambium tissue.
However,despite the cessation of cell division,the process of cell elongation continues,which often leads to abnormal growth patterns in the plant.

(C) The correct answer is $C$.
In these regions,the deficiency of $Zn$ (Zinc) is primarily due to the presence of black soil,which naturally lacks sufficient $Zn$ compounds.
Zinc is an essential micronutrient for plant growth,and its deficiency is a widespread agricultural issue in these states.

(B) Chlorosis is the loss of chlorophyll leading to the yellowing of leaves,which is a primary symptom of nitrogen deficiency.
Nitrogen is a mobile element within the plant.
When nitrogen is deficient,the plant translocates nitrogen from older tissues to younger,actively growing tissues to support their development.
Consequently,the deficiency symptoms,such as yellowing,first manifest in the older leaves before spreading to the younger ones.

(A) The deficiency of $Sulphur$ leads to chlorosis in young leaves.
Leaf tips and margins roll downwards and inwards due to the inhibition of protein synthesis and structural instability.
Examples include $Tomato$ and $Tea$ plants.

(D) Magnesium is an essential mineral required for various physiological processes in the human body.
$1$. It plays a crucial role in the structural integrity of bones,and its deficiency leads to the weakening of bones.
$2$. It is vital for the proper functioning of muscles and nerves,as it acts as a cofactor for many enzymes and regulates ion channels.
$3$. Magnesium deficiency is also associated with various metabolic disturbances,including those that can contribute to anaemia.
Therefore,all the listed conditions can be caused by magnesium deficiency.

(B) Copper is an essential trace element that plays a crucial role in the synthesis of hemoglobin and the formation of red blood cells.
Its deficiency leads to anemia because the body cannot effectively utilize iron for hemoglobin production.
Additionally,copper is vital for the maintenance of the myelin sheath in the nervous system,and its deficiency can lead to damage to the $CNS$ (Central Nervous System).

(C) Magnesium deficiency leads to chlorosis because magnesium is a central component of the chlorophyll molecule. Chlorosis is a condition in which the leaves produce insufficient chlorophyll. When this happens,the leaves do not have their normal green color; instead,they appear pale green,yellow,or yellowish-white. Adding urea (a nitrogen source) to the soil does not compensate for the lack of magnesium,which is essential for chlorophyll synthesis. Therefore,the plant will continue to exhibit symptoms of chlorosis,and the leaves will turn yellow.

(A) Stunted growth is a common symptom of mineral deficiency in plants.
According to $NCERT$,the deficiency of $N$,$K$,$S$,$Ca$,$Mg$,$Cu$,$Mo$,and $Cl$ leads to stunted growth in plants.
Among the given options,option $A$ contains the elements Nitrogen $(N)$,Calcium $(Ca)$,Sulfur $(S)$,and Molybdenum $(Mo)$,which are all known to cause stunted growth when deficient in the plant body.

(D) The grey spot disease in oats is a well-known physiological disorder caused by the deficiency of Manganese $(Mn)$.
Manganese is essential for the activation of various enzymes involved in photosynthesis,respiration,and nitrogen metabolism.
When $Mn$ levels are insufficient,the leaves develop characteristic greyish-brown spots,leading to reduced growth and yield.

(A) The deficiency of $Nitrogen$ $(N)$ leads to the dormancy of lateral buds. $Nitrogen$ is a vital component of amino acids,proteins,nucleic acids,and chlorophyll. When $N$ is deficient,the plant exhibits stunted growth and chlorosis,and the apical dominance is often affected,leading to the inhibition or dormancy of lateral buds.

(C) Nitrogen is an essential macronutrient for plants. The most common symptom of nitrogen deficiency is 'chlorosis',where leaves turn yellow due to a reduction in chlorophyll content. This symptom typically appears first in older leaves because nitrogen is a mobile element in the plant and is translocated from older leaves to younger,developing leaves. Therefore,the correct answer is $C$.

(D) Magnesium is a mobile element in plants. When a deficiency occurs,the plant translocates magnesium from older,mature tissues to younger,developing tissues to support their growth. Consequently,the deficiency symptoms,such as chlorosis (yellowing of leaves due to loss of chlorophyll),appear first in the older,mature leaves before affecting the younger ones.

(D) Molybdenum is an essential micronutrient for plants. It is a vital component of enzymes like nitrogenase and nitrate reductase,which are involved in nitrogen metabolism. $A$ deficiency of Molybdenum primarily leads to symptoms similar to Nitrogen deficiency,such as chlorosis (yellowing of leaves) and stunted growth,because the plant cannot effectively utilize nitrogen. Therefore,the correct answer is that it leads to Nitrogen deficiency symptoms.

(C) The 'Exanthema' disease in citrus plants is caused by the deficiency of $Copper$ $(Cu)$.
$Copper$ is an essential micronutrient that acts as a cofactor for many enzymes involved in redox reactions and lignin synthesis.
Its deficiency leads to the formation of gum pockets in the bark of twigs and branches,a condition known as 'Exanthema' or 'dieback'.

(B) Rickets is a condition that affects bone development in children. It is primarily caused by a severe deficiency of $Vitamin \ D$,calcium,or phosphate. Since it results from the lack of essential nutrients in the body,it is classified as a deficiency disease.

(A) Anemia is a condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body's tissues.
Iron $(Fe)$ is a crucial component of hemoglobin,the protein in red blood cells that carries oxygen.
$A$ deficiency of iron leads to decreased hemoglobin production,resulting in iron-deficiency anemia.
Therefore,the correct option is $A$.

(C) Fluoride toxicity in plants is a common environmental issue. When plants are exposed to high concentrations of fluoride,it accumulates in the tissues. The accumulation of fluoride typically occurs at the sites of transpiration,which are the leaf tips and leaf margins. This accumulation leads to the breakdown of chlorophyll (chlorosis) and the death of tissue (necrosis) in these specific areas.

(D) The deficiency of the trace element $Selenium$ $(Se)$ is known to cause liver necrosis and muscular dystrophy in animals. $Selenium$ is a vital component of the enzyme glutathione peroxidase, which protects cells from oxidative damage. A lack of this element leads to the breakdown of cellular membranes, resulting in tissue damage such as liver necrosis and the degeneration of muscle fibers (muscular dystrophy).

(D) The deficiency of certain mineral nutrients significantly affects the reproductive phase of plants.
$1$. $Boron$ is essential for pollen germination,pollen tube growth,and fertilization; its deficiency leads to poor fruit set and flower drop.
$2$. $Zinc$ is required for the synthesis of $Auxin$ (indole$-3-$acetic acid),which is crucial for fruit development; its deficiency results in stunted growth and poor fruit formation.
$3$. $Calcium$ is vital for cell wall structure and membrane stability; its deficiency can lead to the abortion of flowers and fruits.
Therefore,the deficiency of all these elements can cause a delay or inhibition in flowering and fruit formation.

(D) The correct answer is $Zinc$ $(Zn^{2+})$.
$Zinc$ is an essential micronutrient that acts as a cofactor for numerous enzymes, including carbonic anhydrase and various dehydrogenases.
It plays a critical role in protein synthesis, nucleic acid metabolism, and cell division.
Specifically, $Zinc$ is required for the structural integrity of many proteins and is vital for the repair and regeneration of aging or damaged cells.
Its deficiency leads to stunted growth and the inhibition of essential metabolic processes, including cellular repair mechanisms.

(A) The deficiency symptoms of elements that are actively mobilized within the plants,such as $N$,$K$,and $Mg$,appear first in the older,senescent leaves. This occurs because these elements are transported from the older,senescing tissues to the younger,developing tissues to support their growth. Conversely,elements that are relatively immobile,such as $Ca$ and $S$,show deficiency symptoms first in young leaves.

(A) Calcium $(Ca)$ is an element in plants that is not remobilized.
This is because it is a structural component of the cell wall (as calcium pectate) and hence needs to be localized.
In contrast,elements like Nitrogen $(N)$,Phosphorus $(P)$,and Potassium $(K)$ are not structural components and can be remobilized from older,senescing parts to younger,developing parts of the plant based on their physiological needs.