wbsites to help with homework

plants & photosynthesis
http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/greenworld/photosynthesisrev1.shtml

food chains
http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/food_chains/revision/5/

food webs
http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/food_chains/revision/7/

toxic materials in the food chain
http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/food_chains/revision/9/