NEET BIOLOGY

Detailed explanation-1: -Xylary elements are those which form xylem such as tracheids, vessels, fibres and xylem parenchyma.

Detailed explanation-2: -Gnetophytes are an exception, it is the only gymnosperm, which possesses xylem vessels. The xylem vessels are the long tube-like compositions, which assist in the conduction of water. The existence of vessels in Gnetophyta shows that they were the ancestors of flowering plants.

Detailed explanation-3: -Xylem tissue consists of tracheids, vessels, xylem parenchyma and fibres. The xylem in gymnosperms consists of only tracheids and xylem parenchyma, vessels are absent (exception-Gnetales).

Detailed explanation-4: -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.