The solar system is considered a natural system because it was made and controlled by natural forces, meaning, it was never influenced with human creations. It is considered as one of the products of the phenomenon of the physical world. Hope this answer helps you.
The word I think they use is A mass.
Nervous tissue is made up of neurons and supportive cells. Throughout the human body the neurons carry electrical and chemical signals, while nutrition is provided by the supportive cells.
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.
