ILTs or similar online assessment tasks eg. weekly quiz:
For biology you need to get 50% or more to get the ILT mark.
For chemistry for biomedicine, you just need to do it, they are not counted towards your mark but are required for you to pass. So if you got 0 for all your chemistry for biomedicine ILTs, you can still technically get a 100 for the subject. But I recommend that you still do it properly for practice.
Remember, this does not apply for biology.
Anyone doing physics or EDDA - they count; any mark lost (the online tasks) is lost (or can be compensated if you score well on something else etc. - PM me if you want more information). So for example if you get 90% you'll get 90% for that online component (but remember again for biology if you get 50% or more you'll get 100% for that component).
CHEMCALs - you will get marks taken off if you don't do this for the practical. What score you get isn't taken into account if I am not mistaken, because it is anonymous, so you could do it 10 times in a row for example to get the 100% if you really wanted.
The mid-semester test - every mark is taken into account for all subjects, there is one exception with EDDA where they can compensate through statistical moderation if necessary.
Please note that this information applied for last year and may or may not reflect the current practices of 2013.
Good luck!