I am taking my steps in developing WordPress styles, presently studying the twenty ten theme, and I'm wondering why both index.php and header.php retain the <head> and <body> tags?

@nikolay you're absolutely correct

Within the twenty ten theme, i know and tags isn't contained in both index and header pages. Mostly tag will trouble header file.

In index.php there is a function get_header(), which calls header.php (that has your body and mind tags).

I suggest installing the theme again, because I am there can not be this kind of error for the reason that theme.