Question

Explain factors affecting water absorption.

Hint:

While water absorption is mainly a passive process driven by osmosis, it is also influenced by active mechanisms such as ion transport, essential for maintaining osmotic equilibrium.

Answer 1

Water absorption in plants is determined by both external environmental conditions and internal plant characteristics. Absorption mainly occurs through osmosis at the root hairs and is conducted throughout the plant via the xylem, with several factors influencing the process: 
External (Environmental) Factors: 
1. Soil Water Content: Increased soil moisture availability significantly boosts water absorption. 
2. Temperature: Higher temperatures enhance transpiration, subsequently increasing water uptake. 
3. Soil Aeration: Inadequate aeration restricts the necessary oxygen for root respiration, reducing water absorption. 
4. Soil Salinity: Higher salinity levels lower the water potential, thus decreasing water absorption. 
Internal (Plant) Factors: 
1. Root Surface Area: Larger root hair density increases the efficiency of water absorption. 
2. Transpiration Rate: Higher transpiration rates enhance the gradient for water absorption. 
3. Metabolic Activity: Increased metabolic activity in root cells promotes water uptake through energy-consuming processes.