1. Increased Size and Complexity: Multicellularity allows organisms to grow much larger than single-celled organisms. This is because cells can specialize and work together to form tissues, organs, and organ systems, leading to greater complexity and the ability to perform more complex functions.

2. Increased Specialization and Division of Labor: Multicellular organisms can have different cell types that perform specific tasks. This division of labor allows for greater efficiency and adaptability, as each cell type can be optimized for its particular function. For example, muscle cells specialize in movement, nerve cells specialize in communication, and digestive cells specialize in breaking down food.