Natural Selection - The process by which certain heritable traits that contribute to the survival and reproductive success of an organism become more widespread within a population over successive generations.⏎
Respiratory Tract - The part of the anatomy that has to do with the passage of air and includes the nose, larynx, trachea, and lungs.⏎
Peptic Ulcer - An open sore that develops on the inner lining of the stomach or upper small intestine.⏎
Plasmid - A ring of DNA usually found in bacteria that is separate from and can replicate independently from DNA in a chromosome and can provide bacteria with some advantages, such as antibiotic resistance.⏎