By Anne Marie Helmenstine, Ph.D. Combustion Definition: Combustion is a chemical reaction chemical that occurs between a fuel and an oxidizing agent that produces energy, usually in the form of heat and light.Related Articles.ombustion Definition: Combustion is a chemical reaction chemical that occurs between a fuel and an oxidizing agent that produces energy, usually in the form of heat and light. Related Articles.
It is important to note then that whether a person decides to use alcohol or drugs is a choice, influenced by their environmentâpeers, family, and availability. But, once a person uses alcohol or drugs, the risk of developing alcoholism or drug dependence is largely influenced by genetics.Alcoholism and drug dependence are not moral issues, are not a matter of choice or a lack of willpower.hen an animal eats a certain food that it likes, there is an advantage to associating pleasure with that food so that the animal will look for that food in the future. In other words, the genetic potential for addiction is hardwired into our brain. But some people are better at knowing when enough is enough.
Research into the role of genes in drug addiction has shown that natural variations in proteinsâwhich are encoded by a person's genesâcan lead to differences in how vulnerable that person is to drugs of abuse.se this if you want to print out pictures alongside the body text! The disease known as drug addiction shares many features with other chronic illnessesâone of which is heritability, meaning a tendency to run in families.