Here's why:
* Complex tissues are made up of multiple types of cells that work together to perform a specific function.
* Phloem is responsible for transporting sugars and other organic compounds throughout the plant. It is composed of:
* Sieve tube elements: These are elongated cells with perforated end walls that allow for the flow of sap.
* Companion cells: These cells are connected to sieve tube elements and provide them with metabolic support.
* Phloem parenchyma: These cells store food and provide structural support.
* Phloem fibers: These cells provide mechanical strength.
* Xylem is responsible for transporting water and dissolved minerals throughout the plant. It is composed of:
* Tracheids: These are elongated, dead cells with thickened cell walls that provide strength and prevent collapse.
* Vessel elements: These are wider, shorter, dead cells with perforated end walls that allow for the movement of water.
* Xylem parenchyma: These cells store food and provide structural support.
* Xylem fibers: These cells provide mechanical strength.
Therefore, both phloem and xylem are complex tissues because they are made up of multiple cell types that work together to perform their specific functions.
