Because smoking can cause many different bad things to happen to you some examples would be lung cancer or if you smoke while you are pregnant you cold cause premature or birth defects to the baby, alcohol can just be bad a lot of the time because people can become addicted and loose a lot of money on buying alcohol and/or smoking materials.
The absolute number of molecules of drug required to elicit a response
Plants would be the only option, they have no legs so they can't move. They are producers and make its own food and unable to move around its environment.
Each parent contributes one allele for this trait.
