PLEASE HELP Neurotransmitters can best be described as
A. electrical charges. B. chemical messengers. C. actions. D. reflexes.

Which of the following describes the difference in stimuli required to detect a difference between the stimuli? a. just noticeableb. signal detectionc. subliminald. top down

The smallest parts of these that retain their original properties are called

Which of these is not an example of molecular homology? 1. use of dna and rna as genetic material 2.use of glycolysis as the first step in cellular respiration in both plants and animals 3. the lack of an igf-1 gene in prokaryotes 4. the use of aldolase b to break down fructose in bacteria, plants and animals