Question

Give reasons for the following : i) Cells of sclerenchyma tissue have a narrow lumen. (Hint- nature of wall) ii ) Branches of tree move and bend in high wind velocity .(Hint- Collenchyma)

Answer 1

1) As the sclerenchyma cell is dead, the vacuole of the cell is represented by an empty space called lumen 
2) branches of tree have collenchyma that gives them flexibility to move 

Answer 2

i) lumen are cavities present inside the cell,cells of sclerenchyma tissue have narrow lumen because sclerenchyma are strongly lignified which lead to compressing the cell and thus only narrow cavity is left.
ii)branches of tress move and bend in high speed because of the presence of simple permanent tissue collenchyma.