Mineral nutrition practice · Mixed difficulty

Option C (Copper is an activator for alcohol dehydrogenase) is correct because Zinc, not Copper, is an activator for alcohol dehydrogenase.

Option D (B) is correct because boron (B) is a micronutrient, while magnesium (Mg), sulphur (S), and calcium (Ca) are macronutrients.

Option B (Etiolation) is the correct answer because etiolation is caused by a lack of light, not a mineral deficiency.

Option D (All of the above) is correct because soilless culture allows for precise control over nutrient levels, revealing toxicity, deficiency, and essentiality.

Option B (Nutrient solution) is correct because hydroponics involves growing plants without soil, using a nutrient-rich water solution.

Option B is correct because both the assertion and the reason are true, but the reason does not explain the assertion. Influx of ions into the inner space is active, and ions are available for free exchange in free space.

Option D (Both (1) and (2)) is correct because plants absorb nitrogen from the soil primarily in the form of nitrate ($NO_3^−$) and ammonium ($NH_4^+$) ions.

Option A (17) is correct because there are 17 essential mineral elements required for plant growth.

Option B (A- intercellular space and cell wall, B- cytoplasm and vacuole) is correct because the apoplast consists of the intercellular spaces and cell walls, while the symplast consists of the cytoplasm and vacuole.

Option C (Assertion is true but Reason is false) is correct because while sulphur is a constituent of coenzymes, vitamins, and ferredoxin, it is present in cysteine and methionine, not valine.

Option D (All except II) is correct because hydrogen, oxygen, and nitrogen are components of biomolecules, while magnesium is a macronutrient but not a primary component of biomolecules in the same way.

Option D (III and IV) is correct because $Mg^{2+}$ is an activator of ribulose bisphosphate carboxylase oxygenase (RuBisCO) and phosphoenol pyruvate carboxylase (PEP carboxylase).

Option B (Fe, Cu) is correct because iron (Fe) and copper (Cu) are essential components of enzymes involved in redox reactions in plant cells.

Option C (Glutamic acid) is correct because glutamic acid is the primary amino acid involved in transamination reactions to form other amino acids.

Option A (Rhizobium) is correct because Rhizobium is a nitrogen-fixing bacteria that is symbiotic and not photoautotrophic. Chlorobium, Nostoc, and Anabaena are photoautotrophs.

Option D (Light duration) is correct because while light is essential, the *duration* of light (photoperiod) is less critical for *early* growth compared to micronutrients, temperature, and oxygen.

Option D (Ca, Mg, Cu and K) is correct because deficiency of Calcium (Ca), Magnesium (Mg), Copper (Cu), and Potassium (K) can lead to necrosis, which is the death of plant tissues, particularly leaf tissue.

Option C ((i), (iii) and (iv)) is correct because ions can move passively through channels, actively through carriers, and through both symplast and apoplast pathways.

Option B (Plants will not complete their life cycle) is correct because essential mineral elements are crucial for plant growth and reproduction; their absence prevents completion of the life cycle.

Option A (Delaying of flowering) is correct because nitrogen deficiency often leads to delayed flowering due to its role in overall plant growth and development.

Option B ($C{I^ - }and{K^ + }$) is correct because chloride ($C{I^ - }$) and potassium (${K^ + }$) are the primary ions involved in maintaining cation-anion balance in plant cells.

Option B (Adequately aerated) is correct because hydroponic systems require adequate aeration to ensure the roots receive sufficient oxygen for respiration and nutrient uptake.

Option D (both A and B) is correct because low concentrations of Nitrogen, Sulfur, and Molybdenum can inhibit cell division and delay flowering in plants.

Option C (Acidic) is correct because most vegetables prefer a slightly acidic pH range for optimal nutrient uptake in hydroponic systems.

Option C (${Ca}, {Mg}, {Cu},{K}$) is correct because deficiencies in Calcium, Magnesium, Copper, and Potassium are known to cause necrosis of leaf tissue.

Option A (${N_2} \to N{H_3}$) is correct because biological nitrogen fixation is specifically the conversion of atmospheric nitrogen gas ($N_2$) into ammonia ($NH_3$).

Option A is glutamate synthase. The reaction is $H_2O + NADP \rightarrow NADPH + H^+ + O_2$.

Option A (Parts per million) is correct because parts per million (ppm) is the standard unit for measuring the concentration of nutrients in hydroponic solutions.

Option B (Nitrogenase) is correct because nitrogenase is the enzyme complex responsible for reducing atmospheric nitrogen to ammonia in leguminous root nodules.

Option D (Anabaena) is correct because Anabaena is a nitrogen-fixing cyanobacterium associated with the fern Azolla in rice fields.