Dashes are used to add emphasis or change a topic, as they can either give more importance to an idea or just interrup the idea with another one.
Ellipsis is used to remove unwanted parts of a long quotation and is mostly represented by three consecutive periods. It helps omit unnecesary elements within a sentence.
Commas are used to separate clauses, phrases, coordinating adjectives and non-essential words. Commas usually indicate pauses and they are used to separate ideas within a sentence.
The digestive system cells are possible not as specialized as the nerve cells. Nerve cells have to be made with the ability to transmit neurological messages which could lengthen the process.
