i think it's a good idea for you to have a good idea of what you wanna major in for the science degree, because you're only doing your major subjects- there are no core science subjects or flexible electives like there are with the commerce component. You can think of your commerce major later, you have a good year to think, but you only have 96uoc worth of science subjects, and if your major is something like vision science, you dont have the opportunity to fuck around and try different units to see what you like because vision science is 90uoc (you only have 1 free science elective pretty much). Long story short, pick a major now. LOL.
For example, i'm intending on doing a psychology major, and as there are only 12uoc of level I science courses offered in this major, I need to do another 12uoc of level I science free electives, as an academic rule is that you cant progress to level II science courses before completing at least 24uoc of level I. So, yeah.
I'm getting my commerce cores done this sem, so i have 3 commerce and 1 sci subjects. Next sem, it'll be 3 science and 1 science.