Since the other answer got deleted, i'll just answer it for you.
a sinoatrial node is the main pacemaker that begins each heartbeat located in the junctions of superior vena cava and the right atrium. It signals from the node that spread through the atria and determines the heart rates.
Answer:
Aquaporin protein is a type of protein composed of a bundle of six transmembrane α-helices.
Explanation:
Aquaporin protein is a type of protein composed of a bundle of six transmembrane α-helices. These aquaporin protein have different size of water channels that allow water through to pass through it but it does not allow glucose to move through it due to its large size. The direction of water movement is toward the cell because there is low water inside the cell as compared to outside environment so the water moves inside the cell and rate of water movement slows down over time due to filling of empty spaces with water.
Answer: Abiotic
Explanation: Prairie soil is Non-living, therefore making it Abiotic!
Biotic also means living btw.
I believe that the answer is c gene shape