Cross-section of a flax plant stem with several layers of different tissue types:
1. pith
2. protoxylem
3. xylem
4. phloem
5. sclerenchyma (bast fibre)
6. cortex
7. epidermis

A Tissue forms part of an organ in plants or animals. Tissues are groups of cells that work together to do a job in the body. They are a group of cells having the same origin, structure and function. The cells look the same or almost the same. The work the cells in a tissue do is the same or almost the same.

The four main kinds of tissue in animals are:

1. connective tissue
2. muscles
3. nerves
4. epithelial tissue