Here's a breakdown:

* DNA: The blueprint of life, containing genetic instructions.

* Transcription: The process of copying DNA into mRNA. This occurs in the nucleus of a cell.

* mRNA: A molecule that carries the genetic instructions from DNA to the ribosomes, where protein synthesis takes place.

During transcription, a section of DNA is "unzipped" and one strand is used as a template to create a complementary mRNA molecule. This mRNA molecule then travels out of the nucleus to the ribosomes, where it directs the synthesis of proteins.

It's important to note that human DNA is not spliced into other human DNA. The splicing process refers to the removal of non-coding regions (introns) from the mRNA molecule before it leaves the nucleus.

Let me know if you have any more questions!