TWEL's answer to Jonathan's Secondary 4 Biology Singapore question.

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TWEL
Twel's answer
13 answers (Tutor Details)
1st
1 is dendrite, 2 is axon, 3 is axon terminal.
Dendrites are the receptors, and the impulse travels from 1 to 3.
Since 1 receives and 2 travels, then the output would be 3, making A the answer