As Vendettus said, and to add on,
1) Only if you get A1 for combined science, then they’ll allow
you to take Science subjects at H2 level.
2) If you want to take Bio, you should take Chem as well.
3) If you take any science subjects, they should all be at H2
level. H1 level science is useless as background prerequisite for
Uni admission.
4) Chemistry (of the 3 sciences) is the most required background
subject for applying into Science University courses.
5) Chemistry is the most enjoyable subject at JC level,
definitely more enjoyable than Biology (which is a pity, Biology is
interesting on its own, but at H2/H1 syllabus in Sg JCs, you need
to memorize way too much, and usually without proper understanding,
appreciation or enjoyment).
