I’m not a brain scientist so I’m not sure what the answer is, but I don’t think the scientists who specialise in this kind of thing have figured it out yet either. There certainly is some underlying biological mechanism for consciousness and people are doing lots of tests to find out what it is. If you google it you can find loads and loads of websites and articles about the things that people have managed to find out so far, but there is no conclusive answer as yet!
Well, that is a very difficult question to answer, and I wish I could tell you that I knew how to answer it! I find it amazing that everything we do – thinking, remembering, feeling, problem solving etc – happens inside of our body, which is made up mainly of just oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. How is this possible? Well, I don’t really know the answer and I’m not sure that anyone else really knows either! So there is still lots of scientific research that needs to be done so that we can understand things like this!