Question

Which zone of a root tip increases the surface area for water and dissolved mineral uptake?

Answer 1

Possibly Root hairs or Mycorrhizae

Explanation:

I'm not exactly sure about this, since root hairs are structures found all over the root system and not only at the tips. Just like your question, they increase the surface area for the roots to absorb water and minerals.

Other options could include mycorrhizae. Mycorrhizae is the product of the mutualism between certain species of fungi and plant roots. The plant roots provide shelter and some needed requirements like water and in return, the fungi help the plants absorb nutrients from its environment. The presence of mycorrhizae greatly increases the surface area of roots to interact with the surrounding soil.

There's also a... more obscure answer, one I'm not sure of. If I remember correctly, root tips, especially the root cap release a polysaccharide said to help break down surrounding soil. It's a possibilty that this substance plays a role in helping plants break down soil to obtain minerals. It may or may not have relevance though...