Since the new look of Biology SE there is no link from the main page to the Tour or the Help section. This is bad as it means that people who wish to cannot find the guidelines on asking (especially) and answering questions, and provides an excuse for those who wish to ignore or violate the SE model. How can this be restored?
I noticed the same thing. It is not Bio alone, though. The top bar has been replaced SE-wide. There is still a link to the help center when you click on the hamburger on the top right of your screen.
To be changed, e.g. by placing a help link on the top bar, a Meta.SE question should be asked I guess. I don't think it'll be implemented anytime soon though.