Final answer:
Xylem cells in cross sections of stems and roots can be identified by their characteristics, such as vessel-like structures and thick secondary cell walls with pits.
Step-by-step explanation:
Xylem cells can be identified in cross sections of stems and roots through their distinct characteristics and location within the plant tissues.
1. Xylem vessels are long, tube-like structures that transport water and minerals. They have thinner walls compared to tracheids. In cross sections, xylem vessels can be identified as elongated, hollow structures with open ends.
2. Tracheids are another type of xylem cell that conduct water and provide structural support. They have thick secondary cell walls and tapering ends. In cross sections, tracheids appear elongated and often have characteristic pits on their walls.