Since it is outside your body, the answer is B, external stimulus
The eukaryotic organisms which were neither plants nor animals were placed into the kingdom Fungi. These were yeasts, molds, and the organisms looking like mushrooms. They have chitin in their cell wall. They are heterotrophs and do not photosynthesize.
Such proteins regulate and affect the flow of water through membrane
Answer: Blood comes into the right atrium from the body, moves into the right ventricle, and is pushed into the pulmonary arteries in the lungs. After picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle, and out to the body's tissues through the aorta.
Explanation: use quillbot or wordtone to change it for plagirsim