Whatever you do, just make sure you have the prerequisites for any possible 2nd year program you may be interested in. Some people like to keep ALL their options open and take all the major first year science courses so that they theoretically could go into any 2nd year science program with a minimum of hassle and/or catching up. This does make for a very packed schedule, but it can come in handy - for example, a student may suddenly decide that they hate biology, and opt for going into chemistry in 2nd year (which is exactly what I did...only to later miss biology and switch into biochem :p )
If you know you're heading down the bio/biochem path and need some easier science electives, then the Environmental Science ones are usually a good choice. I personally liked 1G03 the best, but I kinda like geology for some reason...