Gymnosperms are also called soft wood spermatophytes because they lack
cambium
phloem fibres
thickwalled tracheids
xylem fibres.
Xylem vessels and phloem companion cells are generally absent in
How many type of cells constitute a simple permanent tissue
Give functions of companion cells.
Which one of the following is an effective tissue of growing organs with sufficient elasticity
Vessels and companion cells are characteristics of