BIO 224 FINAL EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED LATEST UPDATE GRADED A++

BIO 224 FINAL EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED LATEST UPDATE GRADED A++ Terms in this set (367) What is osmoregulation? maintaining water & salt balance in the body Osmosis water molecules move across a selectively permeable membrane from low solute concentration to high solute concentration Do terrestrial animals need to lose or retain water? Retain water due to dry environment Do aquatic animals need to lose or maintain water to regulate salt balance? Lose water to maintain salt balance What is osmolality? osmotic concentration of a solution (osmotic pressure) What is hyperosmotic? Hyperosmotic- solution inside membrane has higher solute concentration or osmotic pressure than outside the membrane. What is hypoosmotic? Hypoosmotic- solution inside membrane has less solute concentration (or lower osmotic pressure) than outside the membrane. What is isosmotic? Solutions on both sides of membrane have same concentration What type of cellular fluid is used for osmoregulation? ECF which contains blood plasma & interstitial fluid (fluid around the cells) b/c it is capable of varying more than intercellular fluid (inside the cell). What are perturbing solutes & what are they (list 5)? Solutes that indirectly affect macromolecule function such as Na, K, Cl, SO4, & charged amino acids What are compatible solutes? Have little effect in macromolecule function such as: Polyols & uncharged amino acids What are counteracting solutes? Directly disrupt macromolecule function on their own What is transcellular transport? movement through cells across membranes via tight junctions What is paracellular transport? movement between cells via "leaky" epithelia Water can be actively pumped; true or false? False, water relies on an osmotic gradient to move (low solute concentration to high) How do most cells respond to changes in size? Through activation of specific membrane transport or metabolic processes that serve to return cell volume to resting state Approximately what minimum value can cells sense a change in volume? ~3% change in volume can be detected What happens during solute gain in the cell? regulatory volume increase (RVI)- returns the volume back to normal when too little volume occurs What happens during solute loss in the cell? regulatory volume decrease (RVD)- returns volume back to normal when too much volume occurs What are the 3 homeostatic processes of osmoregulation? Ionic regulation- concentrations of specific ions Volume regulation- total amount of water in bodily fluid Osmotic regulation- osmotic pressure of body fluids (such as blood pressure) What are osmoconformers? osmotic concentrations of cellular & extracellular solutions match that of the environment What are stenohaline osmoconformers? marine animals restricted to a narrow range of salinity- cannot regulate osmolytes to compensate What are euryhaline osmoconformers? marine animals tolerant to changes in salinity, regulate organic osmolytes in their cells What are osmoregulators? osmolality of the cellular & extracellular solutions are maintained at a constant state (terrestrial animals) What are 4 problems w/nitrogenous waste? 1. produces ammonia as byproduct of metabolism of proteins & nucleic acids 2. can change Intracellular fluid pH 3. can disrupt functions of the cell membrane 4. can penetrate into CNS & cause swelling & disruption of neurotransmission Ammoniotelic animals? aquatic invertebrates & teleosts (all ray finned fish) invertebrates- diffused out of body surface into surrounding water fish- excreted out of gills (& to minor degree from kidneys) Ureotelic animals? mammals, sharks, rays, & amphibians; tolerated in more concentrated form, sacrifice less water but uses energy to create