University of Southampton Chemistry Lab Absence (Year 1 & 2)

What should I do if...

I know well in advance, that for a valid reason, I am going to miss a lab session?

I know well in advance that I am going to be away on the day when my lab report is due for submission?

It's immediately prior to (i.e. that day or the day before) my lab session and I realise that I am not going to be able to attend?

I have missed a lab session and have not yet informed the relevant parties of the reason for my absence?

I have missed (or will miss) a submission deadline due to an absence/illness between performing the practical and the deadline?