Answer:
Pacemaker cells are located in the <u>sinoatrial node.</u>
Contractile cells are located in the <u>Heart</u>
Explanation:
Toxins are microbial proteins with a strong specificity for a target cell that exert extremely powerful and toxic effects on that cell.
<h3>What are toxins?</h3>
Toxins are molecules that are produced by certain organisms which are deadly to other organisms when these organisms come in contact with them.
Toxins are produces mostly by microorganisms as well as some plants and animals such as fishes.
Toxins are mostly proteins products are usually specific for their targets cells.
Therefore, microbial proteins with a strong specificity for a target cell that exert extremely powerful, and sometimes deadly, effects on that cell are called toxins.
Learn more about toxins at: brainly.com/question/1235358
C: The organelles are enclosed in membranes
This is false. The tube that leads from the mouth to the stomach is called the esophagus. The trachaea leads from the mouth to the lungs, and is used in respiration, not digestion.
Hope that helped! =)
<span>Mammals first appeared during the Cenozoic Era. The statement is true.</span>