What type of substances is filtration useful for seperating? give me an example.

Filtration is useful for separating sediments that are carried in water for easy drinking without the risk of disease - an example of this is a water purifier

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later