Selective permeability, made possible in cells by the phospholipid bilayer that makes up the plasma membrane, is basically monitoring and regulating what can and can't enter the cell. It is carried out by a series of membrane proteins that act as channels to polar molecules, opening to allow them in and closing to prevent their entry. This is possible because the hydrophobic tails of the phospholipid molecules repel polar molecules and so prevent their entry unless through a channel.
1 AU is 149597871 kilometers.
We solve
This gives us .3897114284... AU away from the sun.
Answer:
Many carnivores get their energy and nutrients by eating herbivores, omnivores, and other carnivores.
Answer:
B) astrocytes
Explanation:
Cells other than neurons that play an important role in the normal functioning of nervous system are called Neuroglia or glial cells.
Satellite cells, astrocytes, schwann cells and oligodendrocytes are all examples of glial cells.
⇒Satellite cells provide protection and nutrition to cells in peripheral nervous system ( peripheral nerves and ganglia).
⇒<em><u>Astrocytes</u></em> play an important role in central nervous system (brain and spinal cord). They provide protection to neurons, scavenge ions, form the blood-brain barrier and also maintain extracellular environment suitable for neuronal functioning.
⇒Schwann cells are found in the peripheral nervous system and myelinate the axons of neurons.
⇒Oligodendrocytes are found in central nervous system and produce myelin sheath which myelinates (insulates) axons of neurons. Their function is similar to schwann cells but in the central nervous system.
From the above discussion it is clear that the answer is B) Astrocytes as these maintain a suitable chemical environment for the neurons.
