Types of compound (complex) tissues:

1) Xylem tissue:

Xylem tissue is responsible for the transport of water and dissolved substances from roots to the aerial parts. Due to the presence of lignin, the secondary walls of its cells are thick and rigid. That is why xylem tissue provides support to the plant body.

Types of cells found in xylem tissue:

The following types of cells are found in xylem tissues:

1. Vessel elements of cells:

   These are short and wide cells with thick secondary cell walls. The vessel cells are dead and hollow. They lack end walls and join together to form long tubes.

2. Tracheid:

   These are long cylinder cells with overlapping ends. Water moves upward from tracheid to tracheid.

2) Phloem Tissue:

Phloem tissue is responsible for the conduction of dissolved organic matter (food) between different parts of the plant body.

Types of cells found in phloem tissue:

The following types of cells are found in phloem tissue:

1. Sieve tube cells:

   These are long cells. Their end walls have small pores and are called sieve plates. Many sieve tube cells join to form long pipelines called sieve tubes. During development, they lose their nuclei and ribosomes et cans possess little protoplasm.

2. Companion cells:

   Each sieve tube cell is accompanied by a companion cell. The companion cells contain functional DNA and ribosomes and they make proteins for the sieve tube cells.