I have a question about transcription of DNA and chromatin?

Question

Before gene transcription can commence in eukaryotes, the DNA template encapsulated in chromatin must be exposed.

a.What is the basic structure of chromatin and how is it altered to allow access by the transcriptional machinery?

b.What do you understand by the term “epigenetic code?”

Answer 1

DNA is wrapped around histone proteins which form discs and the DNA helix coils around the outside. This structure in turn coils around itself, which coils again, so the chromosome is a coiled coil of coils. There are lots of other proteins involved as well in chromatin any good molecular biology text will have a good description/ depiction.
Epigenetic code is somewhat misleading as there is no code per se. It refers to phenotypes which were originally observed that seemed to be outside of the classical genetically determined phenotypes. It's kind of a catch all classification for various phenomena such as chromosomal heterochromatinization (permanent shutdown of previously active sections of chromosome), and other ill explained things.

Answer 2

Do your own homework kid!