a)
1. Xylem conducts water and mineral salts from the soil to the apical parts of the plants.
2. It transports materials away from the root.
3. Conduction of water by xylem is unidirectional i.e., from roots to apical parts of the plants.
b)
1. Epidermis usually consists of a single layer of cells.
2. The walls of the cells of epidermis are thicker.
3. The epidermis protects the plants from loss of water, mechanical damage, and invasion by parasitic and disease causing organisms.
