Explain why it is difficult to attach a value to the aesthetic qualities of biodiversity

Because aesthetics is subjective.  Everybody thinks beuty is worth a different amount of money.  Also, the beauty of nature has an unmeasurable effect on the human brain.  We need it to be healthy and relaxed and unstressed, but everyone's brain reacts differently.

integrated circuit (ic) is defined as a set of electronic circuits on one small flat piece of semiconductor material, normally silicon. a functional electronic circuit requires transistors, resistors, capacitors, inductors, etc., and the connections between them.