Test: Cell-Cell Interactions - 2 - MCAT MCQ

Notch signaling involves direct cell-cell contact and interaction between the Notch receptor on one cell and the Delta ligand on the adjacent cell. This form of signaling is known as juxtacrine signaling.

Collagen is a fibrous protein that forms the main structural component of the extracellular matrix. It provides strength and support to tissues and is involved in cell adhesion.

Cadherins are calcium-dependent cell adhesion molecules that play a key role in the formation of adherens junctions, which are cell-cell junctions involved in cell adhesion and tissue integrity.

Endocrine signaling involves the release of hormones into the bloodstream, where they travel to target cells located at distant sites in the body. This form of signaling allows for widespread and systemic communication within the body.

The interaction between an antigen-presenting cell (APC), such as a dendritic cell, and a T cell involves direct physical contact between the two cells. This interaction is necessary for the activation of T cells and the initiation of an immune response.

Selectins are cell adhesion molecules expressed on the surface of endothelial cells and leukocytes. They mediate the initial rolling and attachment of leukocytes to the endothelium during leukocyte extravasation, a process by which leukocytes leave the bloodstream and enter tissues.

In the nervous system, communication between neurons occurs at specialized junctions called synapses. Neurotransmitters are released from synaptic vesicles in the presynaptic neuron and bind to receptors on the postsynaptic neuron, facilitating the transmission of signals between neurons.

The Wnt signaling pathway plays a crucial role in regulating cell proliferation and differentiation during development and tissue homeostasis. It is involved in various cellular processes, including embryonic development, stem cell maintenance, and tissue regeneration.

Gap junctions are formed by connexin proteins and allow for the direct transfer of ions and small molecules between adjacent cells. This communication allows cells to synchronize their activities and coordinate physiological processes.

The interaction between an antibody and an antigen involves direct contact between the two molecules. Antibodies, produced by B cells, bind to specific antigens on pathogens or foreign substances, leading to their neutralization or targeting for destruction by other components of the immune system.