Q.Necrosis means ...............

Chlorosis is the abnormal yellowing (loss of green colour) of plant leaves or other green tissues due to the failure of chlorophyll to form or its breakdown, commonly caused by deficiency of essential mineral nutrient...

Chlorosis is yellowing of normally-green plant tissue, usually from a mineral (especially N, Mg, Fe) deficiency affecting chlorophyll formation.

Chlorosis refers to the condition in which leaves (or other normally green plant parts) lose their characteristic green colour and turn pale yellow or yellowish-white, because chlorophyll either fails to be synthesized adequately or is broken down. It is one of the most common and visually obvious symptoms of mineral (nutrient) deficiency in plants — for example, nitrogen deficiency causes general/uniform chlorosis of older leaves, magnesium deficiency causes interveinal chlorosis (since Mg is a structural component of the chlorophyll molecule), iron deficiency causes chlorosis particularly in younger leaves (since Fe is required for chlorophyll synthesis th …

(d) Copper — copper deficiency causes die-back of shoot tips/twigs (along with chlorosis and reduced lignification) and can be corrected by copper application.

"Die-back of shoots" is a classic copper-deficiency symptom.

Copper is a micronutrient required as a cofactor for enzymes involved in lignin synthesis and electron transport (e.g. plastocyanin, cytochrome oxidase). Its deficiency weakens the vascular tissue and cell walls of young shoots, causing the terminal shoot tips to wilt, blacken and progressively die back from the apex downward — the characteristic "die-back" symptom seen in citrus and other fruit trees, along with stunted growth …

Correct answer: Chlorosis.

Chlorosis is the mineral-deficiency symptom described as the appearance of green and non-green (yellow) patches on leaves.

Mineral deficiencies in plants produce characteristic, recognisable symptoms. Abscission (premature fall of flowers, fruits and leaves) is one such symptom, typically linked to deficiency of elements like zinc or calcium. Chlorosis is another well-known symptom in which the leaf fails to produce or retain adequate chlorophyll uniformly, so patches of the leaf turn pale ye …