AP Biology Unit 4 Exam

Front

What is positive feedback in biological systems?

Back

Positive feedback is a process that amplifies a response or increases the output in a system. An example is blood clotting, where the accumulation of platelets leads to more platelets being attracted to the site of injury.

Front

What is a second messenger in signal transduction?

Back

A second messenger is a molecule that relays signals received at receptors on the cell surface to target molecules inside the cell. An example is cyclic AMP (cAMP), which is involved in many signaling pathways.

Front

What is the consequence of cancer cells ignoring cell cycle checkpoints?

Back

Ignoring cell cycle checkpoints leads to unregulated cell division, allowing cancer cells to proliferate uncontrollably.

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, allowing for rapid signal transmission.

Front

What are 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 the role of receptor proteins in signaling pathways?

Back

Receptor proteins bind to specific ligands (signals) and initiate a cellular response, playing a crucial role in signal transduction.

Front

What can result from a mutation in a receptor protein?

Back

A mutation in a receptor protein can lead to altered signal transduction, which may affect cellular responses and functions.

Front

What is the difference between paracrine and endocrine signaling?

Back

Paracrine signaling involves local signaling where the signal affects nearby cells, while endocrine signaling involves hormones that travel through the bloodstream to distant target cells.

Front

What is apoptosis?

Back

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

Front

What is the function of kinases in signal transduction?

Back

Kinases are enzymes that add phosphate groups to proteins, often activating or deactivating them, and play a key role in signaling pathways.