Q24. Answer Acceptable answers Mark (a) (i) B (1) (a) (ii) Any one of the following Plausible named food such as (1) coffee, brazil nut, bananas Food Space Specified Radon gas medical/industrial use of x-rays Cosmic rays Ignore smoke alarms, power Own bodies stations (in normal use) Fall-out Sun/stars (1) (a) An explanation linking (iii) personal circumstances such  as geographical location nature of their work lifestyle (1) the consequences such as  (2) radiation from radon gas/particular rocks/fallout (eg Chernobyl) greater exposure to x-rays greater exposure to cosmic rays (1) (a) D (1) (iv) (b) (i) From the Any other suitable pair of (2) Time taken to fall (from 120 to) readings from graph 8.1, 8.2 60 Full marks for correct answer even if no working is evident (1) = 8 days (1) (b) 2.2 (days) between 2.0 and 2.5 (1) (ii) 2 (1) (b) Any one of the following: (iii) Mutation of dna  Ionisation of cells  damage / mutate cells (1) (Increases risk of)  cancer (1)
Q24. Answer Acceptable answers Mark (a) (i) B (1) (a) (ii) Any one of the following Food Radon gas Cosmic rays Own bodies Fall-out Sun/stars (1) Plausible named food such as coffee, brazil nut, bananas Space Specified medical/industrial use of x-rays Ignore smoke alarms, power stations (in normal use) (1) (a) (iii) An explanation linking  personal circumstances such as geographical location nature of their work lifestyle (1)  the consequences such as radiation from radon gas/particular rocks/fallout (eg Chernobyl) greater exposure to x-rays greater exposure to cosmic rays (1) (2) (a) (iv) D (1) (b) (i) From the Time taken to fall (from 120 to) 60 (1) = 8 days (1) Any other suitable pair of readings from graph 8.1, 8.2 Full marks for correct answer even if no working is evident (2) (b) (ii) 2.2 (days) (1) between 2.0 and 2.5 2 (1) (b) (iii) Any one of the following:  Mutation of dna  Ionisation of cells  (Increases risk of) cancer (1) damage / mutate cells (1)
p2_revision_pack_mark_scheme.docx