My question is "spontaneously depolarise to trigger contraction of cardiac muscle. establishes the heart rate

Assume that a student is given two different models of bacteria, with one model consisting of big bacteria and the other consisting of small bacteria. how can the student demonstate the theory of endosymbiosis using the models

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain

Isolated volcanic peaks on the ocean floor are