Advanced Placement (AP) Biology Practice Exam

Which signaling type is characterized by a cell influencing itself?

1. Juxtacrine signaling

2. Autocrine signaling

3. Paracrine signaling

4. Synaptic signaling

The correct answer is: Autocrine signaling

Autocrine signaling is a type of cellular communication where a cell produces signals that bind to receptors on its own surface, thereby influencing its own behavior. This is significant in various biological processes, such as immune responses and cell differentiation, where cells need to modulate their activity in response to internal signals. By recognizing their own signals, these cells can initiate a response that may include proliferation, differentiation, or apoptosis, tailoring their behavior to the needs of the organism. In contrast, juxtacrine signaling involves direct contact between neighboring cells, paracrine signaling entails the release of signals that affect nearby cells, and synaptic signaling is specific to neurons communicating across synapses. These other types of signaling highlight the diverse mechanisms of cellular communication but do not involve a cell influencing itself. Thus, the defining feature of autocrine signaling is the self-directed nature of the interaction.