20.3 Regulation of transcription and translation

Question 1

general principles involved in controlling the expression of a gene by controlling transcription

Answer 1

1. for transcription to begin gene is switched on by specific molecules that move from cytoplasm into nucleus (transcriptional factors)
2. each transcriptional factor has a site that binds to a specific base sequence of DNA
3. when it binds causes this region of DNA to begin process of transcription
4. mRNA produced. info it carries is translated into a polypeptide
5. when gene not being expressed