AP BIOLOGY

Detailed explanation-1: -The purpose of the root cap is to enable downward growth of the root, with the root cap covering the sensitive tissue in the root. Also, the root cap enables geoperception or gravitropism. This allows the plant to grow downwards (with gravity) or upwards (against gravity).

Detailed explanation-2: -The root cap, a small tissue at the tip of the root, protects the root from environmental stress and functions in gravity perception.

Detailed explanation-3: -The Columella Cells Contribute to Root Gravity Sensing. In roots, gravity sensing occurs primarily in the cap, an organ that covers the root apical meristem. The root cap serves both as a sensor for several environmental cues and as a protective structure preventing meristem damage as the root grows in soil.

Detailed explanation-4: -Graviperception by plant roots is believed to occur via the sedimentation of amyloplasts in columella cells of the root cap. This physical stimulus results in an accumulation of calcium on the lower side of the cap, which in turn induces gravicurvature.

Detailed explanation-5: -The root cap, or calyptra, has the functions of protecting the delicate stem cells within the root tip, and of receiving and transmitting environmental signals to the growing root.