insecticides

Question 1

definition of bioaccumulation

Answer 1

bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism, through large consumption of smaller organisms which may have the chemical inside it

Question 2

definition of biomagnification

Answer 2

biomagnification is the increase in concentration of a substance, e.g a pesticide, in the tissues of organisms at successively higher levels in a food chain.

Question 3

what are some disadvantages of using insecticides

Answer 3

1. insecticides may become ineffective over time, and insects become resistant to the insecticides by passing the favourable gene to their offspring
2. insecticides may end up affecting biodiversity. when insecticides are carried by rainwater into water bodies, they can accummulate in high concentrations in the bodies of aquatic organisms

Question 4

what is an example of an insecticide which is non-biodegradable

Answer 4

dichloro-diphenyl-trichloroethane (DDT) is a insoluble insecticide which cannot be excreted, and thus accumulates and magnifies in higher levels of the food chain