Besides cardiac muscle, what other tissue type possesses pacemaker cells?

Smooth muscle is another type of tissue that possesses pacemaker cells beside the cardiac mucle. It has a pacemaker activity that can remove the vibration of waves without the present of some external stimuli. In addition, smooth muscle can also start a spontaneous contraction. 

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.