(N/A) Cells of living organisms exhibit three main types of movements:
$(i)$ Amoeboid $(ii)$ Ciliary $(iii)$ Muscular.
$(i)$ Amoeboid Movement: This type of movement is exhibited by organisms like $Amoeba$.
- Some specialised cells in our body,such as macrophages and leucocytes in the blood,also exhibit amoeboid movement.
- It is effected by pseudopodia formed by the streaming of protoplasm.
- Cytoskeletal elements like microfilaments are also involved in amoeboid movement.
- In $Amoeba$,this type of movement is used for obtaining food or changing position.
$(ii)$ Ciliary Movement: This occurs in most of our internal tubular organs which are lined by ciliated epithelium.
- The coordinated movements of cilia in the trachea help in removing dust particles and foreign substances inhaled along with atmospheric air.
- Cilia present in the oviduct and vas deferens transport ova and sperm cells in a specific direction.
- $Paramecium$ performs various functions through ciliary movement.
$(iii)$ Muscular Movement: Movement of our limbs,jaws,and tongue requires muscular movement.
- Muscles show contractility,a characteristic helpful for effective locomotion in humans and other organisms.
- Lower organisms may lack a skeletal system but often possess a muscular system.
- Muscular movement requires the perfectly coordinated activity of the muscular,skeletal,and neural systems.