Which type of cell-cell junction is primarily responsible for direct communication between adjacent cells?

• A. Hemidesmosome
• B. Tight junction
• C. Gap junction
• D. Desmosome

Answer: (C)

Verified step by step guidance

1. Understand the function of each type of cell-cell junction: Hemidesmosomes anchor cells to the extracellular matrix, tight junctions create a seal between cells to prevent leakage, desmosomes provide mechanical strength by linking intermediate filaments, and gap junctions allow direct communication between adjacent cells.
2. Recall that direct communication between cells involves the transfer of ions, small molecules, or signaling molecules, which requires a specialized structure that forms a channel between cells.
3. Gap junctions are composed of connexin proteins that assemble into connexons, forming channels that bridge the cytoplasm of adjacent cells, enabling the exchange of small molecules and ions.
4. Eliminate the other options: Hemidesmosomes and desmosomes are structural junctions, and tight junctions are involved in creating barriers, not communication.
5. Conclude that the correct answer is gap junctions, as they are the only type of junction specialized for direct intercellular communication.