Final answer:
Gymnosperms have tracheids as the tracheary elements in their xylem tissue for conducting water and do not usually contain vessels like those found in angiosperms.
Step-by-step explanation:
Gymnosperms primarily have tracheids as their tracheary elements, which are a type of water-conducting cell in the xylem. Unlike angiosperms, gymnosperms do not generally have vessels in their xylem tissue. Tracheids are elongated cells with a secondary wall and a large lumen, overlapping each other along the long axis of the plant. In gymnosperms, the transport of organic substances like sugars and amino acids occurs in the phloem tissue, which is composed of sieve-tube cells (also called sieve-tube elements), companion cells, phloem parenchyma, and phloem fibers. However, the question's focus is on the tracheary elements of gymnosperms, and hence the presence of tracheids is the correct answer.