Octopus and squid have chemoreceptors on their

octopus have chemoreceptors in the epidermis  

Explanation:

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1.the evidene of the reaction

2.yes

3.yes

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.