Is it possible to switch programs at the start of 2nd year, say i was in biochem, and wanted to switch to bio. I've heard that during the first couple weeks of school, people tend to drop out or switch programs which leaves spots open? is this true?

Yup. Talk to your academic councillor ASAP. It may also depend on your grades but I believe biochem is the harder program. The dropout part is true but better to just switch now.

yea, my friend did biochem first week of this school year and switched to bio. even after a term of biochem you should be able to switch unless youre doing poorly or something.

Keep in mind that it's generally easier to switch from more specialized/smaller to less specialized/larger programs. So for example, switching from biochem to bio is easier than from bio to biochem. If you're not sure which of two programs you want to do, all else being equal, pick the more specialized one so that it's easier to switch later on