Question

bio - 202 topic 1: cellular communication and endocrine system physiology
practice it
what is juxtacrine signaling?
a type of signaling where the signal molecule acts on the same cell that released it
a type of signaling that occurs between adjacent cells
when cells physically touch and transfer signals through proteins on their surface
a type of signaling that involves the release of hormones into the bloodstream
when cells transfer signals through the nervous system

Explanation:

Juxtacrine signaling is characterized by direct cell - cell contact. In this type of signaling, a cell - surface - bound signal molecule interacts with a receptor on an adjacent cell. This direct physical interaction (cells physically touching) and signal transfer through surface proteins is the key feature.

• The first option describes autocrine signaling (signal acts on the same cell that released it).
• The second option is too vague as paracrine signaling (acts on nearby cells) also occurs between adjacent cells but without direct physical contact.
• The fourth option describes endocrine signaling (hormones in the bloodstream).
• The fifth option describes neural signaling (through the nervous system).

Answer:

When cells physically touch and transfer signals through proteins on their surface.