Answer:
1) True
Explanation:
Cells of Sinoatrial (SA) node make up the auto rhythmic cells of heart as in normal physiological conditions , SA-node is responsible to set the pace of the rest of the heart (pacemaker) at a rate of 70 to 80 beats per minute.
The cells of SA node has the ability to self-excite thus able to generate action potential without external stimulation by nerve cells. Thus they initiate the cardiac cycle providing the conduction system.
Hence the statement , SA nodal cells are unique in that they exhibit autorhythmicity, meaning they are capable of depolarizing and firing an action potential spontaneously without any external influence, is true.
Answer:
Water is a chemical compound and polar molecule, which is liquid at standard temperature and pressure. It has the chemical formula H2O, meaning that one molecule of water is composed of two hydrogen atoms and one oxygen atom. Water is found almost everywhere on earth and is required by all known life. About 70% of the Earth's surface is covered by water. Water is known to exist, in ice form, on several other bodies in the solar system and beyond, and proof that it exists (or did exist) in liquid form anywhere besides Earth would be strong evidence of extraterrestrial life.
Explanation:
hope it helps maya
Climate is the biggest one, if it were anything else it would be like the type of ground (kind of like mountains or a valley.) Hope this helps!
S: monotremes................................
