Answer:Action potentials result from the depolarization of the cell membrane (the sarcolemma), which opens voltage-sensitive sodium channels; these become inactivated and the membrane is repolarized through the outward current of potassium ions.
its 'b'
Explanation:
The most important factor that limits the size of a cell is the ability of the cell to transport materials efficiently into and out of the cell. In this case the size of a cell should have a particular form in order to export and import material.
I would say C because, absolute time is in measured in years, C is the only answers that gives a specific year.
Pizza - The sun's energy helped make the pizza because the various ingredients required sunlight, either directly, or indirectly. For example, the cheese is made from cow's milk, and the cow's milk comes from a cow who eats grass (presumably), and the grass feeds off of the sun's energy through photosynthesis. Thus, the cheese is indirectly made with sunlight. Also, the grains used to create the flour used to make the dough used sunlight to grow. Finally, the tomato sauce is made from tomatoes, which are a plant that required sunlight to grow.
I only did one example, but I hope you can make another one with the information I provided yourself! Good luck. :)
The lining of the heart is the pericardium.
