An internal skeleton is used to help an organism hold its body up and keep from falling, while a stem stores nutrients, and produces new living tissue, and transports fluids.
Trace fossil because a trace fossil is a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
The correct answer is c. Genetic Variation. Bacteria are very numerous, ad random mutation of bacterial DNA generates a wide variety of change, including resistance.
Answer:
depolarization leading to action potentials
Explanation:
The voltage-gated Na+ channels are responsible for rapid depolarization phase of the action potential. Action potential generation require depolarization of neuronal membrane which is acquired by influx of sodium ions through voltage gated sodium ion channels. If the Na+ channels are blocked, there will be no influx of sodium ions to cause depolarization hence action potential will not be generated.
