They are involved in production of spindle, basal bodies, centriole, cilia, flagella, etc. Microfilaments are made up of small solid filaments of contractile proteins like acting and myosin. They are present just beneath are plasma membrane.
Function
1. They help in maintaining cell shape.
2. They help in cell division by forming spindle fibers, asters etc.
3. They are involved in motility like amoeboid movement, cytoplasmic streaming.