—— ‘Test Booklet, Unit 2 Study Questions 1 ‘The active transport pump used to move sodium ions across the membranes of gill cells in a freshwater fish has cach of the following characteristics EXCEPT: a) @B) © @) ® It uses osmosis to carry sodium ions into the cells. It requires energy. Ithas a specific binding site for ATP. It has a specific binding site for sodium ions. It is a protein, ‘The rate of transpiration, the flow of water through the stem, and leaf water potential are measured in a tree during a 24-hour period under normal environmental conditions. The results from these measurements are shown in the graphs below. —— Transpiration ‘Transpiration and Stem Flow kg per hr) ae Pe to 2 -s oes EF 49 z -1s o— one All of the following changes would be likely to decrease the rate of transpiration at 8 A.M, EXCEPT a) ®B) © @) ® causing the stomata to close increasing the humidity of the atmosphere increasing the water potential of the atmosphere increasing the water potential of the soil placing the plant in total darkness AP Biology Page 1 of 8ay Tes ost Unit 2 Study Questions 3. bya Got Mitochondtion Figure 1. Simplified diagram of cellular structures of Plasmodium falciparum The cukaryotic protozoan parasite P. falciparum is the causative agent of malaria, P. falciparum cells contain an organelle called the apicoplast (see Figure 1). Apicoplasts synthesize precursors of biomolecules that are required for growth and reproduction of the parasite. ;cher could use to support the claim that (a) Based on Figure 1, deseribe TWO pieces of evidence a re apicoplasts evolved from free-living, prokaryotic organisms, (b) Doxycycline is a drug used to treat malaria and some bacterial infections. Doxycycline binds to the prokaryotic 30S ribosomal subunit and inhibits its function. Explain how doxycycline can be an effective treatment for a P. falciparum infection in humans. 4, Which of the following best describes the primary mechanism of transport whereby carbon dioxide moves from inside a cell to outside the cell’ (A) Carbon dioxide is released when vesicles containing carbon dioxide fuse with the plasma membrane. Carbon dioxide is actively pumped into the membrane between the halves of the bilayer and then passively ®) diffuses out (©) Carbon dioxide passively diffuses between the membrane lipids. (D) Carbon dioxide passively moves through membrane channel proteins, All of the following cell components are found in prokaryotic cells EXCEPT (A) DNA (B) ribosomes (© cell membrane (D) nuclear envelope (B) enzymes, 6 When a substance moves across the plasma membrane along a concentration gradient at arate faster than would be expected by simple diffusion alone but without the expenditure of metabolic energy, the process is best described as Page 2 of 8 AP Biologyay Testo Unit 2 Study Questions (A) facilitated diffusion (B) osmosis (©) active transport (D) pinocytosis (B) the work ofan ion pump The following questions refer to the following diagram. For cach phrase or sentence, select the labeled part to which itis most closely related. Each option may be used once, more than once, or not at all for each group. 7. Site of transport of materials into and out of the cell wa @) B oc (@) D ®E AP Biology Page 3 of 8ay Tes ost Unit 2 Study Questions + Directions: Each group of questions below concerns an experimental or laboratory situation or data. In each case, first study the description of the situation or data, Then choose the one best answer to each question following it and fill in the corresponding circle on the answer sheet. Dialysis tubing is permeable to water molecules but not to sucrose, Four dialysis tubes are half filled with 5 percent, 10 percent, 20 percent, and 40 percent sucrose solutions, respectively, and two dialysis tubes are half filled with distilled ‘water. The dialysis tubes are all sealed at both ends, and the initial masses are determined, Five dialysis tubes are placed into beakers containing distilled water, and the sixth dialysis tube, containing distilled water, is placed into a 40 percent sucrose solution, The masses of the dialysis tubes are recorded at 30-minute intervals for 90 minutes, as shown in the table below. Dialysis Dialysis poator tian MASS (BRAM) Go | Se Number Contents ‘ontents MASS 39 Min 60 Min 90 Min an Saye Diatee Ttw2as coe ae ee ee 5 bites — Dates 182 na ‘The contents of which dialysis tube are initially isotonic to the distilled water in the beaker? a. (B) 2 © 3 @) 4 () 5 Annet movement of water into the beaker occurs in which of the following dialysis tubes? Page 4 of 8 AP Biologyay Tes ost Unit 2 Study Questions a ®) © @) © ‘The following questions refer to an experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% ‘glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot. Distilled water C+ Dialysis-tubing bag with 34 starch and 3% glucose 10. From the initial conditions and results described, which of the following is a logical conclusion?” (A) @) (c Oo) © The initial concentration of glucose in the bag is higher than the initial concentration of starch in the bag, ‘The pores of the bag are larger than the glucose molecules but smaller than the starch molecules. ‘The bag is not selectively permeable. A net movement of water into the beaker has occurred. ‘The molarity of the solution in the bag and the molarity of the solution in the surrounding beaker are the same. 11. If, instead of the bag, a potato slice were placed in the beaker of distilled water, which of the following would be true of the potato slice? ic) @) © ©) © It would gain mass, It would neither gain nor lose mass. It would absorb solutes from the surrounding liquid. It would lose water until water potential inside the cells is equal to zero, The cells of the potato would increase their metabolic activity AP Biology Page 5 of 8Unit 2 Study Questions ‘Test Booklet, 12, A student conducted an experiment to determine the molar concentration of solutes in chicken eggs. Eggs were soaked in vinegar to remove the shells. The eggs were then placed in sucrose solutions of different concentrations. The data arc shown in the table below. ie Initial Mass Final Mass | Change in Mass | Percent Change eaclars @) ®) () in Mass 0 78.50 S73 323 a0 05, 79.11 77.50 =1.61 204 10 80.75 75.14 61 =7.12 2.0 7699 66.64 =10.35 =13.44 (a) Using the most appropriate data, construct a labeled graph on the axes provided below to best illustrate water ‘movement into and out of the egg. Explain why there is a difference in percent of mass change of the eggs in the different sucrose solutions. (b) Using the data, determine the molar concentration of chicken egg cytoplasm and justify your answer. (c) Movement of water and nutrients is critical for the survival of plants. Using the concept of water potential, explain the role of positive and negative pressure in the transport of water and nutrients throughout a vascular plant Page 6 of 8 AP Biologyay Tes ost Unit 2 Study Questions 13. A human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine, The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water. If ADH secretion is inhibited, which of the following would initially result? (A) ‘The number of aquaporins would increase in response to the inhibition of ADH. (B) ‘The person would decrease oral water intake to compensate for the inhibition of ADIL (©) Blood filtration would increase to compensate for the lack of aquaporins. (D) The person would produce greater amounts of dilute urine 14. Membrane-bound organelles have been an important component in the evolution of complex, multicellular organisms. Which of the following best summarizes an advantage of eukaryotic cells having internal membranes? (A) Eukaryotic cells are able to reproduce faster because of the presence of organelles. (B) Some organelles, such as mitochondria and chloroplasts, are similar to prokaryotic cells in structure. (©) Organelles isolate specific reactions, increasing metabolic efficiency. (D) Compartmentalization leads to a higher mutation rate in DNA, which leads to more new species. 15. Which of the following accurately describes a model of active transport? |x) Amembrane channel protein facilitates the movement of molecules from an area of high concentration on (A) the outside of the cell to an arca of lower concentration on the inside. (B) cell ina hypotonic solution swells as water moves into it (©) Amemibrane protein binds a specific molecule outside of the cell and moves the molecule into the cell where there is already a high concentration of the molecule compared with the outside. A membrane protein binds a specific molecule on the inside of the cell and moves the molecule to an area of ower concentration on the outside of the cell. () 16. Which of the following statements is true regarding the movement of substances actoss cell membranes? (a) lons.are unable to move through the phospholipid bilayer because the nonpolar ail regions ofthe phospholipids are hydrophobic. Ions are able to move through the phospholipid bilayer because the polar head regions of the phospholipids (B) are charged. Water is able to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are charged, Water is unable to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged, © © AP Biology Page 7 of 8ay Tes ost Unit 2 Study Questions 17. The table below provides a comparison of nitrogenous waste production in selected organisms. Nitrogenous ] Solubility in | — Amount of Water — | Organisms that Primarily Produce Waste Water | Required for Excretion | the Nitrogenous Waste ‘Ammonia | — High High’ Freshwater fish, aquatic invertebrates Urea ‘Medium Medium ‘Mammals, sharks 7 w ar low Birds, reptiles, and most Mnseactt | egple Vey terresral insects and arthropods Which of the following statements is most consistent with the data in the table? (a)_ In response to the hypotonic environment in which freshwater fish live, they exerete ammonia in concentrated urine or across their gills, (B)_ The kidneys of reptile Birds excrete ammonia in addition to uric acid, and the ratio of the two substances is independent of whether the birds are primarily terrestrial or aquatic species. sded to excrete uric acid. and birds are highly efficient because little water is n © ‘The similar regulation of extracellular fluid volume and composition in all the organisms suggests conservation of kidney structure throughout evolution, ) 18, (Osmolarity of Solution (mM) Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph, Which of the following is the correct explanation for the data? (A) Athigher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia. The contraction rate increases as the osmolarity decreases because the amount of water entering the B ®B) paramecia by osmosis increases. (©) Thscontactil vacuole is less efficient in solutions of high osmolarity because ofthe reduced amount of °) ATP produced from cellular respiration, (py Ianisosmotie sat solution, there is no diffusion of water into or out of the paramecia so the contraction rate is zero, Page 8 of 8 AP Biology