Answer: ions.
- A ions
- B gases
- C large molecules
- D solid grains
Correct answer: A. ions
Explanation: Minerals dissolve in soil water and are taken up as ions.
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.