Final answer:
The contractile vacuole and water potential are discussed in the context of osmoregulation in AP Biology FRQs. The contractile vacuole helps maintain osmotic balance by expelling excess water through exocytosis, avoiding cell rupture. Osmoregulation is critical for all organisms to maintain homeostasis.
Step-by-step explanation:
Osmoregulation and Contractile Vacuoles
In the context of AP Biology FRQs, the contractile vacuole and water potential are typically discussed under the topic of osmoregulation (Option c). A contractile vacuole is an organelle found in some freshwater single-celled organisms, like paramecia, and it functions to maintain osmotic balance by expelling excess water from the cell. This process is crucial because in a hypotonic environment where the surrounding water has a lower concentration of solutes than the interior of the cell, water naturally flows into the cell via osmosis, which could cause the cell to swell and potentially burst.
Regarding the false statements (d.), contractile vacuoles do not function through endocytosis to excrete excess water and uric acid; rather, they expel water through exocytosis. Nor is the efficiency of contractile vacuoles related to the production of ATP from cellular respiration in solutions of high osmolarity; this statement is not accurate in explaining the function of a contractile vacuole. Their primary role is expelling excess water to prevent the bursting of the cell, which is affiliated with the organism's need to maintain a stable internal environment, or homeostasis.
It is important to note that osmoregulation is a critical biological process for all organisms, not only to get rid of metabolic waste but also to maintain a consistent internal environment despite fluctuating external conditions. It allows cells to regulate their internal water balance and ensure proper cell function. If a cell's contractile vacuoles malfunction, the cell could accumulate too much water and potentially lyse or burst.
The term osmotic potential (Option C), also known as solute potential or water potential, is important in understanding osmoregulation. When solutes are added to a cell, solute potential decreases, causing water to flow into the cell to equilibrate osmotic pressures.