Ginger is a rhizome, an underground modified stem growing horizontally, bearing nodes, internodes, scale leaves, and buds. Potato is a tuber, gladiolus a corm, onion a bulb (modified stem with fleshy leaf bases). Rhizomes store food and aid vegetative propagation.
Explanation:
Iron-deficiency anemia is the most prevalent nutritional deficiency worldwide, characterized by fatigue, pallor, and reduced oxygen-carrying capacity. It is treated with iron supplementation and dietary changes.
In plant physiology, the 'Transpiration pull' theory, also known as the cohesion-tension theory, was proposed to explain the ascent of sap in tall trees. The key forces involved are:
A.Osmotic pressure in the leaves
B.Cohesion between water molecules, adhesion to xylem walls, and tension created by transpiration
Explanation:
The cohesion-tension theory, primarily proposed by Dixon and Joly (and later supported by Denison), is the most widely accepted mechanism for the ascent of sap in tall trees. It relies on the physical properties of water. Transpiration from the leaves creates a negative pressure (tension) in the xylem. This tension pulls the water column upwards. The water column remains unbroken due to the high cohesive force between water molecules (hydrogen bonding) and the adhesive force of water to the hydrophilic walls of the xylem vessels and tracheids. This creates a continuous, passive pull from the top.
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