You should talk to your assessor because different providers do it differently.
My assessor sets me certain knowledge questions to answer, then the rest are done as a "professional discussion" where I have had abbreviated notes in front of me and she records me talking on a dictaphone.
She has been out to observe me and this has covered some knowledge as well as some performance criteria. I have also had to answer a group of questions as a written task eg a lot of the health and safety ones and safeguarding. I have also done some reflective accounts to cover the performance criteria that she will never see and also got a lot of witness statements from my colleagues to cover lots of the performance criteria. Lastly, my assessor has cross referenced a lot of the knowledge and performance criteria to prevent me having to repeat myself with similar answers to similar questions across the units.
But as I said, talk to your assessor and find out how they want you to cover the knowledge and performance criteria because it could be a totally different way!
Good Luck....... and if you need any help this is a fantastic site x