Are you serious? So 83 raw yields a 90 exam mark?eco scales much higher and like raw 84-85 in eco is usually a 90, so I'm thinking for bio it should be around raw 86-87? Otherwise that's very strange :/
be prepared for a difficult exam :(
Because we seriously have no idea so expect the worst, and if it's not then that's good for everyone :)
http://community.boredofstudies.org/12/mathematics/327739/2014-2u-maths-predictions.html