Question

Why are xylem and phloem called complex tissues? How are they different from one other?

Answer 1

Complex tissues are made up of more than one type of cells. Both xylem and phloem consists of more than one type of cells, which coordinate to perform a common function.
$\begin{array}{cc}\text{Xylem}& \text{Phloem}\\ \text{Consists of tracheids, vessels, xylem parenchyma}& \text{Consist of sieve tubes, companion cell, phloem}\\ \text{and xylem fibers.}& \text{parenchyma and phloem fibers.}\\ \text{They transport water and minerals vertically from}& \text{They translocate food from leaves to all other parts of}\\ \text{soil to aerial parts of the plant. Its movement is unidirectional.}& \text{the plant. Its movement is bidirectional.}\\ \text{Most of the cells except xylem parenchyma are}& \text{Most of the cells except phloem fibres are living}\\ \text{dead cells.}& \text{cells.}\end{array}$