Deficiency Symptoms Practice Questions
19 free Deficiency Symptoms practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following elements, when deficient, causes the yellowing of leaves due to the loss of chlorophyll (chlorosis)?
- A Ca, B, Cu
- B N, K, Mg
- C P, Si, Al
- D C, H, O
Correct answer: N, K, Mg
Chlorosis is primarily caused by the deficiency of Nitrogen, Potassium, Magnesium, Iron, Manganese, Zinc, and Molybdenum. These elements are vital for chlorophyll synthesis or its structural maintenance.
Why do deficiency symptoms of nitrogen and magnesium appear first in older leaves?
- A They are structural components of the cell wall.
- B They are immobile elements.
- C They are mobile and exported to younger tissues.
- D Older leaves have faster metabolic rates and consume them faster.
Correct answer: They are mobile and exported to younger tissues.
Nitrogen and Magnesium are mobile elements. They are broken down in senescing older leaves and exported to younger, actively growing parts. Consequently, older tissues show deficiency symptoms first as their nutrients are reallocated for new growth.
Deficiency symptoms of which of the following elements appear first in young tissues/leaves?
- A Nitrogen
- B Magnesium
- C Calcium (Ca)
- D Potassium
Correct answer: Calcium (Ca)
Calcium and Sulfur are relatively immobile because they form structural components of the cell (e.g., calcium pectinate in the middle lamella). Since they cannot be easily remobilized from older parts, deficiency symptoms appear first in new, growing tissues.
The death of leaf tissue, particularly at the margins and tips, is called ______ and is caused by the deficiency of ______.
- A Chlorosis; N, S, Mo, Fe
- B Necrosis; Ca, Mg, Cu, K
- C Etiolation; Fe, Mn, Zn, Mo
- D Dwarfism; B, Si, Na, Cl
Correct answer: Necrosis; Ca, Mg, Cu, K
Necrosis is the localized death of tissue. It is specifically associated with the deficiency of Calcium, Magnesium, Copper, and Potassium.
A deficiency of which set of elements inhibits cell division in plants?
- A Fe, Mn, Zn, Cu
- B N, K, S, Mo
- C Ca, Mg, P
- D Na, Si, Co
Correct answer: N, K, S, Mo
Standard plant-nutrition texts list nitrogen, potassium, sulfur, and molybdenum as the elements whose deficiency inhibits cell division, since all four are needed for the nucleic acid and protein synthesis that dividing tissue depends on. Shortages of the other sets listed show up first as chlorosis, necrosis, or poor energy transfer rather than as a block on mitosis.
Delay in flowering in some plants is observed due to the low concentration of:
- A Ca, Mg, K
- B N, S, Mo
- C Fe, Mn, B
- D Zn, Cu, P
Correct answer: N, S, Mo
Nitrogen, Sulfur, and Molybdenum are required for the timely transition of a plant into the reproductive phase. Their deficiency can significantly postpone the onset of flowering.
The appearance of brown spots surrounded by chlorotic veins is a prominent toxicity symptom of:
- A Iron (Fe)
- B Manganese
- C Zinc (Zn)
- D Boron (B)
Correct answer: Manganese
Manganese toxicity manifests as brown spots on leaves. It induces deficiencies of Iron, Magnesium, and Calcium by competing for uptake and binding sites.
Manganese toxicity actually induces the deficiency of which elements by inhibiting their translocation to the shoot apex?
- A Nitrogen and Phosphorus
- B Calcium (Ca)
- C Potassium and Sodium
- D Molybdenum (Mo)
Correct answer: Calcium (Ca)
Manganese competes with Iron and Magnesium for uptake and with Magnesium for enzyme binding. Crucially, it inhibits the translocation of Calcium to the shoot apex, leading to stunted apical growth.
Which of the following is a common method used to correct mineral deficiencies in field crops?
- A Increasing the rate of transpiration
- B Applying mineral fertilizers to the soil
- C Reducing the light intensity
- D Harvesting the plant earlier
Correct answer: Applying mineral fertilizers to the soil
Mineral deficiencies are corrected by supplying the missing element via fertilizers, which can be applied to the soil or as a foliar spray. This restores the nutrient level above the critical concentration.
A farmer notices that the young leaves of his crops are distorted and the growing tips are dying. This is likely a deficiency of:
- A Nitrogen
- B Potassium
- C Calcium (Ca)
- D Magnesium
Correct answer: Calcium (Ca)
Calcium is essential for the stability of the cell wall and the functioning of the mitotic spindle. Because it is immobile, its absence immediately impacts the youngest, most active growing regions like the shoot apex.
To correct chlorosis caused by iron deficiency in an alkaline soil, one should:
- A Add more lime to the soil
- B Use chelated iron or acidify the soil
- C Stop watering the plants
- D Add more sodium chloride
Correct answer: Use chelated iron or acidify the soil
In alkaline soils, iron becomes insoluble and unavailable to plants. Using chelated iron or acidifying the soil helps keep the iron in a soluble form that roots can absorb.
Which element's deficiency is known to cause 'Whip tail' disease in cauliflower?
- A Zinc (Zn)
- B Molybdenum
- C Copper (Cu)
- D Manganese
Correct answer: Molybdenum
Molybdenum deficiency leads to 'Whip tail' in cauliflower, where the leaf blade fails to develop properly, leaving only the midrib. This is a classic example of a specific morphological symptom.
Little leaf disease, characterized by extremely small and crowded leaves, is primarily due to the deficiency of:
- A Iron
- B Zinc
- C Copper
- D Magnesium
Correct answer: Zinc
Zinc is required for the biosynthesis of auxin (indole acetic acid). A deficiency in zinc leads to reduced auxin levels, resulting in stunted leaf growth and the 'little leaf' condition.
Internal cork of apple and browning of cauliflower are symptoms resulting from the deficiency of:
- A Boron (B)
- B Sulfur
- C Chlorine
- D Potassium
Correct answer: Boron (B)
Boron is essential for sugar translocation and calcium utilization. Its deficiency leads to various physiological disorders like internal cork in fruits and browning/hollowing of stems in cauliflower.
Hydroponics can be used to identify deficiency symptoms by:
- A Increasing only the atmospheric carbon dioxide level
- B Testing the tensile strength of the root system
- C Growing plants in soil that has a high salt concentration
- D Growing plants in a solution lacking one element
Correct answer: Growing plants in a solution lacking one element
Hydroponics is a soil-less culture technique. By selectively omitting an element from the nutrient solution, researchers can observe and document the specific deficiency symptoms associated with that element.
Which of the following is true regarding 'Mobile' and 'Immobile' elements?
- A Mobile elements always show deficiency in young leaves first.
- B Immobile elements show deficiency symptoms in older leaves first.
- C Immobile elements are often structural components of cells.
- D All micronutrients are immobile elements.
Correct answer: Immobile elements are often structural components of cells.
Immobile elements like Calcium and Sulfur are part of the cell's structural framework. Because they cannot move from old to new tissues, the new growth suffers first when the supply is cut off.
If a plant shows interveinal chlorosis only in its older leaves, the most likely deficient element is:
- A Iron
- B Manganese
- C Magnesium
- D Calcium
Correct answer: Magnesium
Magnesium is a mobile element and the central atom of chlorophyll. When it is scarce, it is moved from older leaves to younger ones, causing interveinal chlorosis in the older leaves first.
The corrective measure for Manganese toxicity in plants often involves increasing the supply of:
- A Nitrogen (N)
- B Iron and Magnesium
- C Copper (Cu)
- D Molybdenum (Mo)
Correct answer: Iron and Magnesium
Since Manganese toxicity interferes with the uptake and utilization of Iron and Magnesium, increasing the availability of these two elements can help mitigate the toxic effects.
Which element's deficiency is associated with the 'Die-back' disease in citrus fruits?
- A Zinc (Zn)
- B Copper
- C Iron (Fe)
- D Boron (B)
Correct answer: Copper
Copper deficiency causes 'Die-back' of shoots, where the tips of the branches begin to wither and die. Copper is vital for various redox enzymes in the plant.