<p>I don’t see the problem with taking both bio and chem. They’re both very interesting and will prepare you for college style science. I have taken classes science classes at my local college and they are helpful in terms of better understanding background information. Also, it looks good on your application and the extra points. 
Colleges will see you challenged yourself.</p>
<p>I personally love science so my judgment may be a little bias ^^. Either way, if you like science go for it.</p>