Channel proteins that form a narrow passageway in gap junctions are known as <span>connexons
</span><span>Connexons are assemblies of six proteins that form a pore or a narrow passageway between the cytoplasm of two adjacent cells.
These passageways allow the bidirectional passage of iron and signals between the cells. </span>
<span />
Most eels breed at depths unattainable to modern diving equipment, which is why no-one has ever seen the eel mate with other eels.
This is the best answer I can do.
I think the answer is c hope is right
Commensalism because the birds is benefiting but the tree is not harmed