Plant Transport and Physiology

Nitrogen deficiency in plants leads to chlorosis and premature leaf fall, as nitrogen is essential for chlorophyll production and protein synthesis.

Guttation is the exudation of drops of xylem sap on the tips or edges of leaves through specialized pores called hydathodes.

Permanent wilting occurs when the soil water content drops to a level where the plant can no longer extract enough water to maintain turgor pressure. This is directly caused by the poor availability of water in the soil, even if the plant is physiologically healthy.

Molybdenum is essential for nitrogen metabolism. Its deficiency often manifests as interveinal chlorosis, mottling, and necrosis of leaves, particularly in older leaves first.

 Xylem tissue is involved in water conducting system of plants; so if it is blocked, the plant will show wilting. The process of wilting modifies the leaf angle distribution of the plant (or canopy) towards more erectophile conditions.

The starch-sugar interconversion theory, which explains stomatal movement based on the osmotic changes resulting from starch hydrolysis to glucose, was proposed by Sayre and later supported by Steward.

The Cohesion-Tension theory, which is the most widely accepted explanation for the ascent of sap, was proposed by Dixon and Jolly.

Heterophylly is the phenomenon where a single plant exhibits different leaf shapes or sizes, often due to environmental factors or developmental stages. Venation refers to the pattern of veins, while vernation is leaf arrangement in the bud.

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The pulvinus is a joint-like thickening at the base of a leaf or leaflet that facilitates leaf movement in response to stimuli, such as in the 'Touch-me-not' (Mimosa pudica) plant.

Mimosa pudica's leaf folding response (thigmonasty) occurs due to rapid turgor pressure changes in pulvini cells - specialized motor cells at leaf bases. When touched, potassium ions exit these cells, water follows, and turgor drops.

Xylem is the specialized plant tissue responsible for the upward transport of water and dissolved minerals from the roots to the rest of the plant.

Stomata are small openings or pores, typically found on the underside of leaves, that facilitate gas exchange for photosynthesis and respiration.

Transpiration is the biological process by which plants release water vapor from their leaves into the atmosphere.

Xylem conveys water and dissolved minerals from the roots to the rest of the plant.