Select the correct answer. In what order do these three organ systems of the human body operate during a reflex arc in response to a stimulus of sharp pain to the hand?
A.
muscular, nervous, skeletal
B.
nervous, muscular, skeletal
C.
skeletal, nervous, muscular
D.
skeletal, muscular, nervous

How does the molecular clock work? a. it analyzes the brain functionality of two different species. b. it examines and compares the physical characteristics of two different species. c. it illustrates relationships between two different species. d. it compares the number of mutations that exist in the dna of two different species.

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?