HOMEOSTASIS MIDTERM EXAM 2025

What would most likely happen to a unicellular organism if it was exposed to a hypotonic solution for an extended period of time? - -it would swell and then burst. Chlorophyll is found in plant leaves and absorbs light from the sun to enable plants to perform photosynthesis. Magnesium is an important component of chlorophyll. The concentration of magnesium ions is higher in the root-hair cells of plants than in the soil. Which mechanism of ion uptake would best enable a plant to produce a steady supply of chlorophyll? - -active transport Which homeostatic process moves particles against a concentration gradient? - -active transport Which reason best explains why the cell membrane helps the cell maintain homeostasis? - -the cell membrane is selectively permeable. Which homeostatic process is characterized by the diffusion of water molecules? - osmosis For diffusion to occur, which condition must be met? - -a concentration gradient must exist. Which motion of particles across a membrane requires energy? - -from low concentration to high concentration Which solution would most likely cause a plant placed in it to become firmer and more rigid? - -hypotonic Which adaptation is used by polar bears to maintain internal homeostasis in cold temperatures? - -blubber Which homeostatic process requires energy to move particles across the plasma membrane? - -active transport Which best defines homeostasis? - -maintaining a stable internal environment Which movement of particles would be most affected by a disorder that causes damage to carrier proteins? - -active transport Which best describes dynamic equilibrium? - -particles are moving into and out of the cell, but their concentrations remain stable. The role of the cell membrane is most like the job of which person? - -a police officer who allows select people to enter and leave a crime scene Homeostasis Reptiles and birds excrete waste as an insoluble white solid that is called uric acid. How does this help them to maintain internal homeostasis in hot climates? - -by retaining water How would the contractile vacuole of a freshwater amoeba respond if the organism was placed in seawater? - -with fewer contractions Water makes up a large percentage of the body's cells. For a cell to remain in homeostasis, there must be a mechanism to control water changes in the cells. The movement of water from an area of high water concentration to an area of low water concentration is: ______ - -osmosis The data in the graph are the result of a paramecium being placed in a hypertonic salt solution. Based on the data in the graph, which would most likely happen if the paramecium were placed in distilled water? The contractions would increase. - -the contractions would increase. - - Ureters - -transport urine from kidneys to urinary bladder Urethra - -transport urine from urinary bladder to exterior Elimination - -discharge of urine into environment Excretion - -removal of waste products from body fluids Urine - -end product of kidney function Urea - -produced by the liver; less toxic form of ammonia Nephron - -functional unit of the kidney Urinary bladder - -temporary storage for urine Adh - -hormone that tells kidneys to reabsorb more water Toxins, drugs, urea - -common substance found in urine Transitional epithelium - -tissue type that makes up urinary bladder Micturition reflex - -series of contractions of the urinary bladder Homeostasis Homeostasis Glomerulus - -ball of capillaries in the nephron Bowman's capusle - -cup-shaped structure that surrounds the ball of capillaries (where filtrate goes) Collecting duct - -end product of nephron filtration is funneled here Adrenal gland - -found on top of each kidney Renal cortex - -outer region of kidney Renal medulla - -inner region of the kidney Renal pelvis - -space within kidney that collects urine Medullary pyramids - -triangular shaped tissue inside kidney Renal columns - -extensions of cortex in between pyramids Calyx - -cup shaped structure at the bottom of each pyramid that drains urine away Filtration - -water and solutes cross into glomerulus Reabsorption - -water, ions and nutrients that the body can use are ________________ from nephron Secretion - -materials left in the renal tubule move toward the ureter Dialysis - -when kidneys don't function well this procedure can be done to help Homeostasis of the body done by kidney - -regu