Signals are transmitted from one neuron to the next neuron, by molecules. These statements are about this process:

1 Transmitter molecules are formed in the receptors.
2 The signal is transmitted across the synapse by osmosis.
3 Transmitter molecules are released once the signal has been transmitted across the synapse.
4 The release of transmitter molecules is triggered by an impulse.
5 The signal is transmitted across the synapse by diffusion.
Which of the above statements are correct?

Answer:

13) F

1 – Wrong
Transmitter molecules diffuse to the receptors to be recognised. They are not formed in the receptors.

2 – Wrong
The signal is transmitted across the synapse by diffusion

3 – Wrong
This statement does not even make sense. Transmitter molecules are released before the signal is transmitted across the synapse.

4 – Correct
It is an impulse which causes the transmitter molecules to be released.

5 – Correct
The signal is transmitted across the synapse by diffusion.

Hence, 4 and 5 is correct.