Why are xylem and phloem called complex tissues?

Answer: Phloem and Xylem are known as complex tissue because these are the tissues that contain more than 1 cell in them and this is why they are complex in nature and are called complex tissues.

Both the xylem and phloem are cells that coordinate together for the purpose of carrying out different functions in a proper manner.

But the xylem and phloem are separate from each other because the function of the xylem is to transfer water to the leaves from their roots and the function of the phloem is to transmit foods from the leaves.