AP BIOLOGY

Detailed explanation-1: -Correct answer: "Gap junctions prevent molecules and ions from traveling between cells in the extracellular space” is incorrect because this describes the function of tight junctions. Gap junctions electrically couple two cells by permitting the formation of small channels that connect two cells.

Detailed explanation-2: -Gap junctions permit the travel of small molecules back and forth between adjacent cells. Gap junctions have some functionality of permitting cells to adhere to one another. Correct answer: Gap junctions prevent molecules and ions from traveling between cells in the extracellular space.

Detailed explanation-3: -Gap junctions are aggregates of intercellular channels that permit direct cell–cell transfer of ions and small molecules. Initially described as low-resistance ion pathways joining excitable cells (nerve and muscle), gap junctions are found joining virtually all cells in solid tissues.

Detailed explanation-4: -Gap junctions are channels that physically connect adjacent cells, mediating the rapid exchange of small molecules, and playing an essential role in a wide range of physiological processes in nearly every system in the body, including the nervous system.