Q.Which of the following statements are true? If false, correct them:

This question asks for the truth value of four statements about mineral nutrition, with corrections where false.

(a) "Boron deficiency leads to stout axis."

• True. One of the well-documented effects of boron deficiency is inhibition of cell elongation. Since cell division at the meristems is not equally affected, the plant continues producing new cells without the corresponding elongation, resulting in a shortened, thickened ("stout") stem axis rather than the normal, elongated growth habit. (Boron deficiency also causes death of the apical bud/meristem and disrupts pollen germination and fruit/seed set.)

(b) "Every mineral element that is present in a cell is needed by the cell."

• False. Plant roots take up a wide range of ions from the soil solution somewhat non-selectively, so cells routinely contain elements that have no demonstrated metabolic function — these may be beneficial only to certain species, purely incidental contaminants, or even toxic in excess. Only elements satisfying the criteria of essentiality (indispensable, specific, directly involved in metabolism) are truly "needed."
• Correction: Not every mineral element present in a cell is actually needed by the cell — many are present without serving any essential function.

(c) "Nitrogen as a nutrient element, is highly immobile in the plants."

• False. Nitrogen is, in fact, one of the classic examples of a highly mobile nutrient. It is readily broken down from proteins/chlorophyll in older leaves and retranslocated via the phloem to younger, actively growing tissues when overall nitrogen supply is limited. This mobility is exactly why nitrogen deficiency symptoms (chlorosis) characteristically appear first in the older, mature leaves rather than the young ones.
• Correction: Nitrogen as a nutrient element is highly mobile in plants (not immobile).

(d) "It is very easy to establish the essentiality of micronutrients because they are required only in trace quantities." …

Evaluate each statement (a)-(d) against known physiology: boron's specific effect on cell elongation, the essentiality criteria vs. mere presence, nitrogen's known high phloem mobility, and the practical difficulty of e …

• Marking (a) false by confusing "stout axis" (a real, documented effect of inhibited elongation) with a made-up symptom.
• Marking (c) true by conflating "required in small amounts" with "immobile" — mobility refers to retranslocation within the plant, not the quantity required. …