A simple mechanical tissue devoid of lignin is
Parenchyma
Collenchyma
Sclerenchyma
Chlorenchyma
Collenchyma is
The difference in phloem of gymnosperms and angiosperms is due to
All xylem elements when mature are dead except
$A$ : Cells of sclerenchyma have thickened secondary walls.
$R$ : Cells have deposition of lignin.
The function of a vessel is