The five levels of organisation in a multicellular organism are:

Cells → tissues → organs → systems → organism

Cells are the smallest structural and functional units of life from which every living thing is composed. In a living organism, there are different types of cells, each having a particular function.

Some of the different types of cells found in plants include leaf epidermal cells, leaf palisade cells, and root tip cells.

(i) Cells found in the human body: The different types of cells found in the human body include skin cells, blood cells, muscle cells, nerve cells, sperm, and ova cells. Cells of a particular type are usually grouped together to form a tissue. Tissue consists of cells of the same shape and size, which carry out the same function.

Plant Tissue

Animal Tissue

(ii) Organs: Tissue may be grouped together to form a functional unit called an organ. An organ consists of a number of different tissues, which combine to enable the organ to perform specific functions.

Plant Organs

Animal Organs

(iii) Systems: Organs may be grouped together to form a system. A system consists of several organs whose functions are coordinated.

Plant Systems