Question

peptic ulcers are caused by damage to the wall of the stomach by the acids that help digest food. this can be caused by the failure of ___.
tight junctions
adhering junctions
gap junctions
plasmodesmata
adhering and gap junctions

Explanation:

Tight junctions form a seal between adjacent cells, preventing substances (like stomach acid) from leaking between them. If tight junctions fail, stomach acid can damage the stomach wall, leading to peptic ulcers. Adhering junctions are for cell - to - cell adhesion, gap junctions for inter - cellular communication, and plasmodesmata are in plant cells.

Answer:

tight junctions