newbie question about DNA and cells

[Bob]

On 31 Dec 2003 07:13:02 -0800, eric at pegasi.net (Eric Hanson) wrote:

>Hello,
>
>I'm a computer scientist interested in genetics and cellular biology. 
>I have a decent understanding of the process of DNA getting converted
>to RNA, from there to enzymes, but have a question.
>
>Each cell has the same DNA as its base, and yet one cell might become
>a piece of tooth enamel and one might become a piece of toenail.  If
>they each have the same DNA, how does the cell know what to become?
>

Eric,

The posted reply from jai is about as good as you are going to get for
a brief post.

If you want to follow this up, a good book to start with is D P Clark
& L D Russell, Molecular Biology made fun and simple. 2/e, 2000.
(check if there is a new one?). It is a quite inexpensive paperback,
which provides a good and very readable intro to a wide range of basic
mol biol. They have  a lot of fun, but the science is sound, and the
book is used as an intro level textbook. It is a from a small
publisher, and not available from some standard sources -- tho of
course you can check. Suggest you check the publisher’s web site,
www.cacheriverpress.com

bob