In: Biology
Which of these cell junctions form a barrier to the passage of materials?
a). keratin fibers
b). tight junctions
c). plasmodesmata
d). desmosomes (anchoring junctions)
f). gap (communicating) junctions
The correct answer is option B that is tight junctions.
The tight junction is the only junction that does not allow any molecules to pass where else all other options allow some of the molecules to pass.