Cells in the human eye send nerve impulses to the brain that cause the pupil to constrict. this is an example of a reaction to what kind of internal stimuli? a. chemicals b. light c. touch d. sound

5) these are organisms where the genetic material is not bound by a nucleus. they are usually unicellular.

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.

How are proteins and nucleic acids related? they both provide energy. they both carry genetic information. the structure of proteins is determined by nucleic acids. the subunits of nucleic acids are also the subunits of proteins.