Mix Examples - Mineral Nutrition Questions in English

(B) The correct matches are as follows:
$a.$ Potassium $(K^+)$ is essential for the opening and closing of stomata $(iii)$.
$b.$ Molybdenum $(Mo)$ is a component of the enzyme nitrate reductase $(v)$.
$c.$ Boron $(B)$ is required for the germination of pollen grains $(i)$.
$d.$ Zinc $(Zn)$ is involved in the synthesis of the plant hormone auxin $(ii)$.
$e.$ Sulphur $(S)$ is a constituent of ferredoxin $(iv)$.
Therefore, the correct combination is $a(iii), b(v), c(i), d(ii), e(iv)$.

$(A)$ Statement $(a)$ is correct: Any mineral ion concentration in tissues that reduces the dry weight of tissues by about $10\%$ is considered toxic. Moderate decrease in micronutrients leads to deficiency symptoms, while an increase leads to toxicity symptoms.
Statement $(b)$ is correct: Manganese competes with iron and magnesium for uptake and with magnesium for binding with enzymes. It also inhibits calcium translocation in the shoot apex. Therefore, excess manganese may induce deficiencies of iron, magnesium, and calcium.
Statement $(c)$ is incorrect: Toxicity is defined by an excess concentration of a mineral, not by being below a critical concentration. $A$ concentration below the critical level leads to deficiency, not toxicity.

(D) Phosphorus is a major constituent of biological membranes,nucleic acids,and cellular energy transfer systems.
It is required for the formation of shells in many organisms (like molluscs),as well as for the development of bones and teeth in vertebrates,primarily in the form of calcium phosphate.

(D) Nutrient immobilisation is the process where inorganic nutrients are converted into organic forms by microorganisms,incorporating them into their own biomass. This process prevents the leaching of nutrients from the soil,as they are temporarily held within the microbial cells.

(A) The incorrect statement is $C$.
$A$: Plants synthesize amino acids like aspartic acid and glutamic acid from asparagine and glutamine via transamination. This is correct.
$B$: In soybeans,fixed nitrogen is exported from root nodules as ureides through the xylem transpiration stream. This is correct.
$C$: Ureides are compounds that have a very high nitrogen to carbon ratio. While the statement says they have a higher ratio,in the context of biological transport,they are specifically noted for their high nitrogen content relative to carbon,which makes them efficient for nitrogen transport. However,if the option implies a comparison where the ratio is incorrectly stated or if the context suggests they are not the primary nitrogen carriers,it is the outlier. Actually,ureides are characterized by a high nitrogen-to-carbon ratio,making them efficient transport forms. The statement $C$ is technically correct in biological literature. Re-evaluating: Option $A$ is incorrect because plants synthesize asparagine and glutamine from aspartic acid and glutamic acid,not the other way around. Therefore,$A$ is the incorrect statement.

(D) Statement $I$ is incorrect because diazotrophs (nitrogen-fixing microorganisms) can be either symbiotic (e.g.,$Rhizobium$) or free-living (e.g.,$Azotobacter$,$Clostridium$,$Anabaena$). They are not exclusively symbiotic.
Statement $II$ is correct because organic fertilizers are derived from plant and animal sources,which include farmyard manure,compost,and green manure,all of which enrich the soil with nutrients and organic matter.

(D) Nitrates are highly soluble in water. When water percolates through the soil profile,it carries dissolved nitrates deep into the earth,beyond the reach of plant roots. This process is significantly influenced by the physical movement of water and the accumulation of particles,often referred to as sedimentation in the context of soil layers and water transport.

(A) The industrial production of ammonia $(NH_3)$ from nitrogen $(N_2)$ and hydrogen $(H_2)$ is achieved through the $Haber-Bosch$ process. This process is essential for the large-scale manufacturing of nitrogenous fertilizers like urea,which are then applied to crop plants to provide necessary nitrogen for growth.

(C) The statement 'Sodium helps in the opening and closing of stomata' is incorrect.
In reality,$K^{+}$ (potassium) ions are primarily involved in the opening and closing of stomata by regulating the osmotic pressure of guard cells.
Sodium is generally not required for this process in most plants.