6. Transcription takes place in the of a cell. , an enzyme, binds to the DNA. It separates the strands of DNA, which is then used as a template to create a complementary molecule. This newly built molecule then leaves the nucleus and enters the cytoplasm of the cell.

1. Nucleus

2. RNA polymerase

3. mRNA

Explanation:

Transcription is the first process of gene expression in which a DNA strand is used to synthesize a mRNA molecule. In the process of transcription, which occurs in the NUCLEUS, an enzyme called RNA polymerase binds to the DNA molecule.

The enzyme separates the double stranded DNA and the uses the complementary base pairing rule i.e. A-U, G-C to synthesize a mRNA molecule that is complementary to the DNA template strand. This newly built mRNA molecule then leaves the nucleus and enters the cytoplasm of the cell for translation to occur.