Germany undergrad: is it possible to switch from medicine to biology? My niece in Germany is applying for undergrad colleges, at this point she likes medicine and biology both. But she is not sure if she wants to end up being a doctor or a molecular biology researcher. It seems that the German system bifurcates from undergrad itself between medicine and biology - so in her case what would be a good option if she wants to do an undergrad and at the end of that decide to continue with medicine or focus fully on biology? If not possible in Germany, are there other European universities where this is possible?
In the German system, there are many courses of study that cannot accommodate as many students as who would like to enroll. This is also the reason for what you called a bifurcation -- without doing that early, i.e., at the beginning of the studies, the university would have problems allocating the needed resources.
Many universities have both restricted courses of study and courses that are completely open for anyone with a high school degree to enroll.
Note that Medicine is a full course of study taking at least 6 years. It's not a typical undergrad course of study. It should certainly be possible to study for a M.Sc degree in a related discipline afterwards, though. But that is rarely necessary - your niece could jump into research in an area related to her doctoral studies during the MD degree, if desired (many MDs have their doctoral thesis done before even getting their MD degree).
Switching from biology to medicine will be difficult due to the access restriction to the medicine course of study, at the very least without first finishing the complete biology course of study.