The right answer is <span>Refractory period.
At the moment when the action potential is emitted, the fiber being depolarized, it is impossible to depolarize it again. It is, therefore, necessary to wait until the membrane potential returns to a value below the critical threshold in order to be able to excite it again. We are thus led to distinguish two periods that characterize its excitability.
An absolute refractory period: during which any stimulation, even supraliminal, is ineffective since the fiber is already depolarized.
A relative refractory period: during which a second action potential can be omitted provided that the depolarization produced by the excitation reaches the critical threshold, which implies that it is more important since the value of the resting potential has not been restored yet.</span>
Answer:
I think bacterial cell becausea microscope look into small organisms that we can't see with a naked eye
An unidentified prokaryotic cell. Thus, option "4" is correct.
<h3>What atr prokaryotes and eukaryotes?</h3>
Prokaryotes are the unicellular organisms that do not contain nucleus and membrane bound organelle in their cell. Their genetic material is present in the cytoplasm.
On the other hand, eukaryotes have true nucleus that contains the genetic material (DNA). They also contain membrane bound specialised organelles (such as mitochondria, endoplasmic reticulum, golgi complex).
Thus, option "4" is correct.
To learn more about Prokaryotes click here:
brainly.com/question/15329345
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D.the particle is a cell becayse it does not make proteins and cannot reproduce by itself
