Answer:
Cell membrane
Explanation:
Sumer has come up with a great analogy for a presentation she is giving in her psychology class. The membrane encasing a neuron only allows some ions to pass in and out of its channels. And she is going to describe this cell membrane as a guard only allowing some patrons to enter and leave a controlled area.
<span>The busiest phase of the cell cycle is the interphase</span>
D is correct. Cool air sinks, which forces warm air to rise.
Convection is when warm material rises and cool material sinks
Hope it helps
