Answer: Increasing the surface area in contact with soil moisture.
- A Producing root pressure that pushes water up the stem
- B Releasing enzymes that break down soil minerals
- C Storing reserve water for use during dry spells
- D Increasing the surface area in contact with soil moisture
Correct answer: D. Increasing the surface area in contact with soil moisture
Explanation: Root hairs are thin, elongated extensions of epidermal cells that greatly increase the surface area available for absorbing water and minerals from soil.
Water can travel through cell walls (apoplast) or cell-to-cell through the cytoplasm (symplast) - but the Casparian strip at the endodermis blocks the apoplast route entirely, forcing everything through a selectively permeable membrane (symplast) before it can enter the xylem.
Concept context
Water and mineral absorption, the ascent of sap, transpiration, and phloem transport via the pressure flow hypothesis.