What defines a mixture? a. it cannot be broken down into simpler substances. b. it can be described by a single chemical formula. c. it can be created through a chemical reaction. d. it can be broken down into its basic substances through physical means.

this protocol provides a detailed procedure for chromatin immunoprecipitation (chip) to study the dna-protein interactions.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.