AP Biology Unit 4 Exam

Front

What is Gap Junctions?

Back

Gap junctions are specialized intercellular connections that allow direct communication between adjacent cells through channels that permit the passage of ions and small molecules.

Front

What is negative feedback in biological systems?

Back

Negative feedback is a regulatory mechanism in which a change in a physiological variable triggers a response that counteracts the initial change, helping to maintain homeostasis.

Front

What occurs at the G2 checkpoint in the cell cycle?

Back

At the G2 checkpoint, if DNA is damaged, the cell attempts to repair the damage before proceeding to mitosis.

Front

What role does phosphorylation play in signal transduction?

Back

Phosphorylation regulates protein activity and gene expression by adding a phosphate group to proteins, which can activate or deactivate their function.

Front

What is an example of positive feedback?

Back

Blood clotting is an example of positive feedback, where the process amplifies itself until a specific outcome is achieved.

Front

What is Synaptic Signaling?

Back

Synaptic signaling is a form of communication between neurons where neurotransmitters are released from one neuron and bind to receptors on another neuron.

Front

What is Paracrine Signaling?

Back

Paracrine signaling involves the release of signaling molecules by a cell that affect nearby target cells in the local environment.

Front

What is Endocrine Signaling?

Back

Endocrine signaling is a form of long-distance communication in which hormones are released into the bloodstream and travel to target organs or cells.

Front

What is the function of the cell cycle checkpoint?

Back

Cell cycle checkpoints are control mechanisms that ensure the proper progression of the cell cycle, preventing damaged or unprepared cells from dividing.

Front

What is apoptosis?

Back

Apoptosis is a programmed cell death process that eliminates damaged or unnecessary cells in a controlled manner.