In step 1, the insulating plate (such as plastic) becomes positive charged when rubbed with cloth. what is the name of this phenomenon?

An insulating plate, such as plastic, tends to be positively charged when rubbed with cloth due to the piezoelectric effect. This phenomenon involves certain materials to generate charged particles as a response to mechanical stress applied to it. In this case, the mechanical stress was due to the rubbing motion. 

C) to ensure each new cell has an exact copy of the dna