EVERYDAY SCIENCE

Detailed explanation-1: -Vessel elements (vessel members, vessel segments of some authors) may be defined as xylem cells in which one or more pitlike structures lack a pit membrane at maturity, thus forming perforations.

Detailed explanation-2: -Most gymnosperms lack vessel elements in their xylem, unlike flowering plants which have both vessels and tracheids. The vessel element is typically found in the Angiosperms (flowering plants) and it is absent in the Gymnosperms as these plants do not produce flowers.

Detailed explanation-3: -Final Answer: Tracheids do not have perforated cell walls.

Detailed explanation-4: -The function of companion cells is to support sieve elements by carrying out cell metabolism and regulation. Companion cells have a dense cytoplasm with abundant organelles, vacuoles, and large nuclei. They load and upload metabolites into the cavity of sieve elements.