Older parts of plant roots do not normally absorb water because
Answer Details
Older parts of plant roots do not normally absorb water because they lack root hairs. Root hairs are tiny protrusions from the epidermal cells of the root that increase the surface area for water and mineral absorption. As roots get older, the root hairs wear out and do not regenerate, leading to reduced surface area and a decrease in the plant's ability to absorb water and minerals. However, the xylem, which transports water and minerals, is present in the entire length of the root, including the older parts.