Answer:
<u>
They have hydrophilic heads and hydrophobic tails.</u>
Explanation:
Phospholipid membranes are comprised of a chain of lipids. These typically are arranged in a bilayer; the hydrophilic lipid heads are polar, and face outwards, while the hydrophobic tails are polar facing inwards.
The membranes are selectively permeable, and only allow the movement of small, non-polar molecules through the bilayer.
Answer:
Autorhythmicity of the heart
Explanation:
It is the study of the characteristics features of the cardiac muscle cells with the ability to initiate action potential at certain level without connection to any external stimulus which the heart beats constantly and rhythmically. Cardiac muscle cells controls the rate of contraction of heartbeats.