Explain how a toxin in a food web will harm some while killing others why did the mosquito and cats die while other things lived

I think that a toxin that was introduced into a food web can kill some species but not others because some may have resistances to the toxin, while others, it may be lethal. Also that it did not affect everyone because as Bioaccumulation has stated if affected one organism but their might not be much biomagnification as in much increase in the correlation between the food chains in that area. i think the cat were like the top animal so the key stone animal of the food chain and also it had no predators. 

The main role of dna in the  cell is the long-term storage of information. it is often compared to a blueprint, since it contains the instructions to construct other components of the  cell, such as  proteins  and rna molecules.the main function of rna is to carry information of amino acid sequence from the genes to where  proteins  are assembled on  ribosomes  in the  cytoplasm. mark brainliest, my work is good.