AP Biology Unit 4 Review

Front

What are plasmodesmata?

Back

Plasmodesmata are microscopic channels that traverse the cell walls of plant cells, allowing for the exchange of small soluble compounds and communication between neighboring cells.

Front

What is positive feedback in biological systems?

Back

Positive feedback is a process that amplifies a response or increases the output of a system. An example is immune cells releasing inflammatory cytokines, which further stimulate the immune response.

Front

How do prokaryotic and eukaryotic cell communication processes compare?

Back

The processes of cell communication are very similar in prokaryotic and eukaryotic cells, indicating that cell communication has evolved over billions of years.

Front

What is signal transduction?

Back

Signal transduction is the process by which a cell responds to external signals, often involving the binding of a hormone to a receptor and the subsequent activation of intracellular signaling pathways.

Front

What role do enzymes play in signal transduction?

Back

Enzymes can pass phosphate groups down a series of proteins in a signaling cascade, which helps to amplify and propagate the signal within the cell.

Front

What is the function of ADH (Antidiuretic Hormone)?

Back

ADH is primarily involved in osmoregulation, helping to control the body's water balance by promoting water reabsorption in the kidneys.

Front

What are gap junctions?

Back

Gap junctions are specialized intercellular connections that allow for direct communication between adjacent cells, facilitating the transfer of ions and small molecules.

Front

What is the difference between positive and negative feedback mechanisms?

Back

Positive feedback amplifies a response, while negative feedback reduces or dampens a response to maintain homeostasis.

Front

What is the significance of cAMP in cellular signaling?

Back

cAMP (cyclic adenosine monophosphate) acts as a secondary messenger in many signaling pathways, activating protein kinases and leading to various cellular responses.

Front

What is osmoregulation?

Back

Osmoregulation is the process by which organisms regulate the balance of water and solutes in their bodies to maintain homeostasis.