Deficiency Symptoms of Essential Elements Questions in English

(A) Manganese toxicity in plants often leads to the appearance of symptoms associated with deficiencies of other mineral elements. This occurs because excess manganese competes with iron and magnesium for uptake and translocation,and it also inhibits calcium translocation to the shoot apex. Therefore,the symptoms of manganese toxicity are often characterized by the appearance of deficiencies of $Fe$,$Mg$,and $Ca$.

(D) Manganese toxicity in plants leads to several physiological disturbances.
$1$. It competes with iron and magnesium for uptake by the roots.
$2$. It competes with magnesium for binding with enzymes involved in photosynthesis and respiration.
$3$. It also inhibits the translocation of calcium to the shoot apex.
Therefore,all these effects are observed due to manganese toxicity.

(C) The correct matches for mineral deficiency symptoms are as follows:
$i$. Chlorosis: This is the loss of chlorophyll leading to the yellowing of leaves $(i-c)$.
$ii$. Necrosis: This refers to the death of tissues,particularly in leaves,often due to deficiency of $Ca, Mg, Cu, K$ $(ii-a)$.
$iii$. Mottling: This is the appearance of green and non-green patches on leaves $(iii-d)$.
$iv$. Abscission: This refers to the premature fall of flowers,fruits,and leaves due to inhibition of cell division $(iv-b)$.
Therefore,the correct sequence is $i-c, ii-a, iii-d, iv-b$.

(C) The correct matches are as follows:
$1$. Chlorosis (loss of chlorophyll) is primarily caused by the deficiency of Magnesium $(Mg)$, which is a central component of the chlorophyll molecule $(A-III)$.
$2$. Brown heart disease in plants (like sugar beet) is caused by the deficiency of Boron $(B-I)$.
$3$. Die-back of shoots is a characteristic symptom of Copper $(Cu)$ deficiency $(C-IV)$.
$4$. Malformed leaves (or little leaf) is a common symptom of Zinc $(Zn)$ deficiency $(D-II)$.
Therefore, the correct matching is $A-III, B-I, C-IV, D-II$.

(C) The die-back disease in $Citrus$ plants is a physiological disorder caused by the deficiency of the micronutrient $Copper$ $(Cu)$.
Symptoms include the yellowing of leaves,death of terminal shoots,and the formation of gum pockets in the bark.
Therefore,the correct option is $C$.

(C) Boron is an essential micronutrient for plants. It is required for pollen germination,cell elongation,cell differentiation,and carbohydrate translocation. $A$ characteristic symptom of boron deficiency is the death of shoot and root tips (meristematic tissues) because boron is essential for cell division and cell wall formation.