The opening of which of the following types of ion channels will lead to a depolarization? A chemically gated sodium channel 2) a voltage gated sodium channel 3) A mechanically gated sodium channel 4) All of them

All of them will lead to depolarisation.

Depolarisation is a phenomenon ebochor occurs in the excitable tissues of our bodies, namely the neurons and the muscle T junctions. Here the membrane is already polarised by means of difference in charges as well as concentration of ions on both sides of the cell membrane. With a single stimuli, this change in concentration is gone, and this is de polarisation.

This phenomenon occurs because of the opening of the ion channels like potassium channels and sodium channels which leads to a diffusion of ions from both sides to the other achieving a more or less equal concentration on both sides of cell membrane.

Now this opening of the ion channels can be triggered by means of different stimuli. In case of neurons, the opening of the post synaptic ion channels are guided by the chemical impulse taking in synapse.

In case of inter neuron transfer, the ion channels open due to change in voltage of the previous part of the axon.

In case of organ of Corti, the sodium channels open due to mechanical events occurring inside cochlea. So ion channels can open in any form will lead to change in potential.

chordata is the answer

i think the answer is b.