(a) We need to water the soil in plants on a regular basis. But it ultimately reaches the leaves of the plant. Explain how this takes place. OR (b) Name the type of nutrition exhibited by Amoeba. Explain how food is taken in and digested by this organism.

(a) Water is absorbed from the soil by the roots of terrestrial plants. It is transported upwards to the leaves through specialized vascular tissues called xylem (vessels and tracheids). This upward movement is driven by:

1. Root Pressure: Active transport of ions into root cells creates a concentration gradient, pushing water into the xylem at the base.
2. Transpiration Pull: Evaporation of water molecules from the stomata of leaves creates a suction pull (transpiration pull) that continuously draws water upwards from the roots to the leaves.

OR

(b) Amoeba exhibits holozoic (heterotrophic) nutrition.

• Ingestion: Amoeba takes in food using temporary, finger-like extensions of its cell surface called pseudopodia. These extensions fuse over the food particle, engulfing it to form a food-vacuole.
• Digestion: Inside the food-vacuole, complex food substances are broken down into simpler soluble substances by digestive enzymes. These simpler substances then diffuse directly into the cytoplasm. The remaining undigested material is moved to the cell surface and thrown out (egestion).