The two types of currents are direct current, which is abbreviated DC. And alternating current, which is abbreviated AC.
Answer:
Through natural selection the disease gain immunity to the antibiotic.
Explanation:
As the antibiotic kills off the members of the population that are not resistant, leaving only the resistant members. These members then reproduce, passing the immunity to their offspring, causing the population to become immune.
The myelin sheath that covers many cns axons is formed by oligodendrocytes.
Oligodendrocytes are type of neuroglia (non-neural cells found in central nervous system) with protective, trophic and supportive role. Their function is to insulate axons (with myelin sheath), in the central nervous system (CNS) which is, equivalent to the function performed by Schwann cells in the peripheral nervous system (PNS).
