Advanced science has a higher UAI cutoff, so transferring has to go though UAC and will depend on any university marks you achieve. However, I think all of the study plans offered in advanced science can be just about followed course for course to satisfy the requirements of a science degree. They do allow slight relaxation of the formal major requirements, but you may be able to negotiate similar changes yourself.
For example the Neuroscience plan is basically as a Physiology major, Psychology minor. However, the requirements on core 3rd year physiology courses are relaxed in the adv. science plan. Even so it is still possible for a science student to take all the courses required for the adv. science degree and meet the stricter major requirements.