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:
a controls what enters and leaves the cell
Explanation:
I believe it is A.Simple epithelia form impermeable barriers. If I am not right I'm really sorry. I don't really know much about it :)
Use the equation F = ma
Force: 12 N
Mass: 2 kg
Acceleration: ?
12 N = (2kg)(a)
acceleration = 6 m/s^2
If this answer helped you, please vote me as brainliest!
Answer:
B. Gravel has more porosity than sand
Explanation:
Porosity is the gap between stuff. Water would go through gravel easier than sand. Definition of Porosity is -(of a rock or other material) having minute spaces or holes through which liquid or air may pass.