It is because that in eukaryotes the erticular tissue used to do one function...so they follow division of labour.

Division of labour

- In a multicellular organism, tissues are groups of cells that work together to perform a specific function.
- The presence of tissues allows for the division of labour among different cell types, which is essential for the proper functioning of the organism.
- Each tissue specializes in carrying out a particular task, such as providing support, transporting nutrients, or protecting the body.
- This division of labour increases the efficiency and effectiveness of the organism's overall functions.

Specialization of cells

- Within a tissue, different cells may have specific structures and functions that enable them to carry out their specialized tasks.
- For example, in muscle tissue, some cells are responsible for contraction, while others provide support and coordination.
- The specialization of cells within tissues allows them to perform their functions more efficiently, leading to improved overall performance of the organism.

Efficient functioning

- By dividing the various tasks and functions among different tissues, multicellular organisms can operate more efficiently.
- Each tissue can focus on its specific function, allowing it to become highly specialized and optimized for that task.
- This specialization leads to improved efficiency and effectiveness in performing the necessary functions for the organism's survival and well-being.

Coordination and communication

- The presence of tissues in a multicellular organism also enables better coordination and communication between different parts of the body.
- Tissues can communicate with each other through chemical signals, electrical impulses, and physical connections.
- This coordination ensures that the various tissues work together harmoniously and respond appropriately to internal and external stimuli.

Overall benefits

- The division of labour provided by tissues in a multicellular organism results in several advantages:
- Faster development: Specialized tissues can carry out their functions more efficiently, leading to faster growth and development of the organism.
- Higher reproductive potential: Tissues such as reproductive tissues enable the organism to reproduce and pass on its genetic information to the next generation.
- Body strength: Tissues like muscle tissue provide the organism with the ability to move, support its structure, and exert force.
- Therefore, the presence of tissues in a multicellular organism ensures division of labour, which leads to improved efficiency, coordination, and overall functioning of the organism.