True or False: all cells have a cell membrane.

A True
B False​

True

Explanation:

all cells have plasma membrane ( cell membrane ) the plasma membrane, or cell membrane, is the phospholipid layer that surrounds the cell and protected from outside

 True.

Explanation:

All cells in the world have a outer plasma membrane that regulates not just what enters the cell, but also how much of any given substance comes in the cell. But unlike prokaryotes, eukaryotic cells also have membranes on the inside of them that protect their organelles and also control the exchange of important cell parts.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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liquid crystals are matters in a state which have properties between those of conventional liquids and those of solid crystals[1]. liquid crystal is partially ordered and anisotropic. in terms of molecular order, liquid crystal molecules have one-dimensional or two-dimensional long - range order.