Skip to content
Textbook Guides

Solution Manual for Laboratory Manual for Anatomy and Physiology, 6th Edition

Solution Manual for Laboratory Manual for Anatomy and Physiology, 6th Edition is here to help you with textbook problems, offering clear solutions and helpful explanations.

Preview 16 of 170 pages

See the first 16 pages exactly as they appear in the document.

  1. Page 1
    Read page 1 as text

    1 1 The Language of Anatomy E x E r c i s E If time is limited, most of this exercise can be done as an out-of-class assignment. Time Allotment: ½ hour in lab. Multimedia Resources: See Appendix B for a list of multimedia resource distributors. Biology Essentials: The Human Body: The Ultimate Machine (CBS, 22 minutes, DVD) Advance Preparation 1. Set out human torso models and have articulated skeletons available. 2. Obtain three preserved kidneys (sheep kidneys work well) and three bananas. Cut one of each in trans- verse section, one in longitudinal section (usually a sagittal section), and leave one uncut. Label the kid- neys and put them in a demonstration area. You may wish to add a fourth kidney to demonstrate a frontal section. 3. The day before the lab, prepare gelatin or Jell-O ® spaghetti using slightly less water than is called for and cook the spaghetti until it is al dente. Pour the gelatin into several small molds and drop several spaghetti strands into each mold. Refrigerate until lab time. 4. Set out gelatin spaghetti molds and scalpel. Comments and Pitfalls 1. Students will probably have the most trouble understanding proximal and distal; other than that there should be few problems. Answers to Activity Questions Activity 2: Practicing Using Correct Anatomical Terminology (p. 3) 1. The wrist is proximal to the hand. 2. The trachea (windpipe) is anterior or ventral to the spine. 3. The brain is superior or cephalad to the spinal cord. 4. The kidneys are inferior or caudal to the liver. 5. The nose is medial to the cheekbones. 6. The chest is superior to the abdomen. M01_MARI5487_05_C01_pp001-003.indd 1 10/02/16 10:14 AM

  2. Page 2
  3. Page 3
    Read page 3 as text

    R E V I E W S H E E T 2 The Language of Anatomy Surface Anatomy Name Lab Time/Date E x E R c I S E 1 acromial brachial carpal cervical crural digital patellar popliteal scapular vertebral crural 1. lower portion of the lower limb digital 2. referring to the fingers popliteal 3. posterior aspect of the knee scapular 4. shoulder blade region carpal 5. wrist area 1. Match each of the following descriptions with a key term, and record the term in front of the description. Key: patellar 6. anterior aspect of knee brachial 7. referring to the arm vertebral 8. backbone, or spine acromial 9. point of the shoulder cervical 10. referring to the neck Body Orientation, Direction, Planes, and Sections 2. Several incomplete statements are listed below. Correctly complete each statement by choosing the appropriate anatomical term from the key. Write the key terms on the correspondingly numbered blanks below. Some terms may be used more than once. Key: anterior inferior posterior superior distal lateral proximal transverse frontal medial sagittal In the anatomical position, the umbilicus and knees are on the 1 body surface; the calves and shoulder blades are on the 2 body surface; and the soles of the feet are the most 3 part of the body. The ears are 4 and 4 to the shoulders and 5 to the nose. The breastbone is 6 to the vertebral column (spine) and 7 to the shoulders. The elbow is 8 to the shoulder but 9 to the fingers. The thoracic cavity is 10 to the abdominopelvic cavity and 11 to the spinal cavity. In humans, the ventral surface can also be called the 12 surface; however, in quadruped animals, the ventral surface is the 13 surface. If an incision cuts the brain into superior and inferior parts, the section is a 14 section; but if the brain is cut so that anterior and posterior portions result, the section is a 15 section. You are told to cut a dissection animal along two planes so that the lungs are observable in both sections. The body plane that would not meet these criteria is 16 . 1. anterior 2. posterior 3. inferior 4. superior medial 5. lateral 6. anterior 7. medial 8. distal 9. proximal 10. superior 11. anterior 12. anterior 13. inferior 14. transverse 15. frontal 16. sagittal 2 3. A nurse informs you that she is about to give you a shot in the lateral femoral region. What portion of your body should you uncover? Side of upper thigh M01_MARI5487_05_C01_pp001-003.indd 2 10/02/16 10:14 AM

  4. Page 4
    Read page 4 as text

    4. Correctly identify each of the body planes by inserting the appropriate term for each on the answer line below the drawing. 1. Median (mid-sagittal) plane 2. Frontal 3. Transverse Body Cavities 5. Which body cavity would have to be opened for the following types of surgery? (Insert the key term(s) in the same-numbered blank. More than one choice applies.) Key: abdominopelvic dorsal thoracic cranial spinal ventral 1. surgery to remove a cancerous lung lobe 1. thoracic/ventral 2. gastric bypass surgery to reduce the size of the stomach 2. abdominopelvic/ventral 3. surgery to remove a ruptured disk 3. spinal/dorsal 4. appendectomy (surgical removal of the appendix) 4. abdominopelvic/ventral 5. removal of a brain tumor 5. cranial/dorsal 6. removal of the gallbladder 6. abdominopelvic/ventral 6. Correctly identify each of the described areas of the abdominal surface by inserting the appropriate term in the answer blank preceding the description. hypochondriac region 1. overlies the lateral aspects of the lower ribs umbilical region 2. surrounds the “belly button” hypogastric region 3. encompasses the pubic area epigastric region 4. medial region overlying the stomach 7. What are the bony landmarks of the abdominopelvic cavity? Rib cage and pelvis 8. Which body cavity provides the least protection to its internal structures? Abdominopelvic cavity Review Sheet 1 3 M01_MARI5487_05_C01_pp001-003.indd 3 10/02/16 10:14 AM

  5. Page 5
    Read page 5 as text

    4 2 E x E r c i s E Organ Systems Overview Time Allotment: 1½ hours (rat dissection—1 hour; human torso model—½ hour). Multimedia Resources: See Appendix B for a list of multimedia resource distributors. Homeostasis (FHS: 20 minutes, DVD, 3-year streaming webcast) Homeostasis: The Body in Balance (HRM, IM, 26 minutes, DVD) Advance Preparation 1. Make arrangements for appropriate storage and disposal of dissection materials. Check with the Department of Health or the Department of Environmental Protection, or their counterparts, for state regulations. 2. Designate a disposal container for organic debris, set up a dishwashing area with hot soapy water and sponges, and provide lab disinfectant such as Wavicide-01 (Carolina) for washing down the lab benches. 3. Set out safety glasses and disposable gloves for dissection of freshly killed animals (to protect students from parasites) and for dissection of preserved animals. 4. Decide on the number of students in each dissecting group (a maximum of four is suggested; two is prob- ably best). Each dissecting group should have a dissecting pan, dissecting pins, scissors, blunt probe, for- ceps, twine, and a preserved or freshly killed rat. 5. Preserved rats are more convenient to use unless small mammal facilities are available. If live rats are used, they may be killed a half hour or so prior to the lab by administering an overdose of ether or chloroform. To do this, remove each rat from its cage and hold it firmly by the skin at the back of its neck. Put the rat in a container with cotton soaked in ether or chloroform. Seal the jar tightly and wait until the rat ceases to breathe. 6. Set out human torso models and a predissected rat. Comments and Pitfalls 1. Students may be overly enthusiastic when using the scalpel and cut away organs they are supposed to locate and identify. Have blunt probes available as the major dissecting tool and suggest that the scalpel be used to cut only when everyone in the group agrees that the cut is correct. 2. Be sure the lab is well ventilated, and encourage students to take fresh air breaks if the preservative fumes are strong. If the dissection animal will be used only once, it can be rinsed to remove most of the excess preservative. 3. Organic debris may end up in the sinks, clogging the drains. Remind the students to dispose of all dissec- tion materials in the designated container. M02_MARI5487_05_C02_pp004-007.indd 4 10/02/16 10:16 AM

  6. Page 6
    Read page 6 as text

    Answers to Activity Questions Activity 6: Examining the Human Torso Model (pp. 15–16) Digestive: esophagus, liver, stomach, pancreas, small intestine, large intestine (including rectum), gallbladder Urinary: kidneys, ureters, bladder Cardiovascular: heart, descending aorta, inferior vena cava Endocrine: thyroid gland, pancreas, adrenal gland Reproductive: uterus Respiratory: lungs, bronchi, trachea, diaphragm Lymphatic: spleen Nervous: brain, spinal cord, medulla of adrenal gland Exercise 2 5 M02_MARI5487_05_C02_pp004-007.indd 5 10/02/16 10:16 AM

  7. Page 7
    Read page 7 as text

    6 R E V I E W S H E E T urinary 1. rids the body of nitrogen-containing wastes endocrine 2. is affected by removal of the adrenal gland skeletal 3. protects and supports body organs; provides a framework for muscular action cardiovascular 4. includes arteries and veins endocrine 5. composed of glands that secrete hormones integumentary 6. external body covering lymphatic 7. houses cells involved in the body’s immune response digestive 8. breaks down ingested food into its absorbable units respiratory 9. loads oxygen into the blood cardiovascular/endocrine 10. uses blood as a transport vehicle muscular 11. generates body heat and provides for locomotion of the body as a whole urinary 12. regulates water and acid-base balance of the blood reproductive and endocrine 13. necessary for conception and childbearing integumentary 14. is damaged when you fall and scrape your knee 1. Using the key choices, indicate the body systems that match the following descriptions. Then, circle the organ systems (in the key) that are present in all subdivisions of the ventral body cavity. Key: Name Lab Time/Date Organ Systems Overview E x E R c I S E 2 cardiovascular integumentary nervous skeletal digestive lymphatic reproductive urinary endocrine muscular respiratory 2. Using the above key, choose the organ system to which each of the following sets of organs or body structures belongs: lymphatic 1. lymph nodes, spleen, lymphatic vessels respiratory 4. trachea, bronchi, alveoli skeletal 2. bones, cartilages, ligaments reproductive 5. uterus, ovaries, vagina endocrine 3. thyroid, thymus, pituitary gland cardiovascular 6. arteries, veins, heart M02_MARI5487_05_C02_pp004-007.indd 6 10/02/16 10:16 AM

  8. Page 8
    Read page 8 as text

    Review Sheet 2 7 3. Using the key below, place the following organs in their proper body cavity. Some responses may be used more than once. Key: abdominopelvic cranial spinal thoracic abdominopelvic 1. stomach abdominopelvic 6. urinary bladder thoracic 2. esophagus thoracic 7. heart abdominopelvic 3. large intestine thoracic 8. trachea abdominopelvic 4. liver cranial 9. brain spinal 5. spinal cord abdominopelvic 10. rectum 4. Using the organs listed in item 3 above, record, by number, which would be found in the following abdominopelvic regions: 3, 6, 10 1. hypogastric region 1, 3, 4 4. epigastric region 3 2. right lumbar region 3 5. left iliac region 3 3. umbilical region 1, 3 6. left hypochondriac region 5. The five levels of organization of a living body, beginning with the cell, are as follows: cell, tissue , organ , organ system , and organism. 6. Define organ: A structure composed of two or more tissues that performs a specialized function 7. Using the terms provided, correctly identify all of the body organs provided with leader lines in the drawings below. Then name the organ systems by entering the name of each on the answer blank below each drawing. Key: blood vessels heart nerves spinal cord urethra brain kidney sensory receptor ureter urinary bladder 1. Nervous 2. Cardiovascular 3. Urinary Brain Sensory receptor Spinal cord Nerves Heart Blood vessels Kidney Ureter Urinary bladder Urethra M02_MARI5487_05_C02_pp004-007.indd 7 10/02/16 10:16 AM

  9. Page 9
    Read page 9 as text

    8 3 E x E r c i s E The Cell—Anatomy and Division The Anatomy of the Composite Cell section can be given as an out-of-class assignment to save time. This might be necessary if audiovisual material is used. Time Allotment: 2 hours. Multimedia Resources: See Appendix B for a list of multimedia resource distributors. The Cell: Structure, Function, and Process (HRM, CD-ROM) Inside the Living Cell (WNS, 50 minutes, DVD) An Introduction to the Living Cell (CBS, 30 minutes, DVD) A Journey Through the Cell (FHS, 2-part series, 25 minutes each, DVD) Mitosis and Meiosis (DE, 23 minutes, DVD) Advance Preparation 1. Set out slides (one per student) of simple squamous epithelium, teased smooth muscle, human blood cell smear, sperm, and whitefish blastulas. Students will also need lens paper, lens cleaning solution, immer- sion oil, and compound microscopes. 2. Set out a model or a lab chart of a composite cell and models of mitotic stages. 3. Set out chenille sticks and chalk. 4. If available, arrange a viewing area for the mitosis video. Comments and Pitfalls 1. Observing differences and similarities in cell structure often gives students trouble, as many of them have never seen any cells other than epithelial cells. Slides or pictures of these cell types might help. Answers to Activity Questions Activity 5: Observing Differences and Similarities in Cell Structure (p. 22) 3. Simple squamous epithelial cells are relatively large and irregularly (“fried egg”) shaped. Smooth muscle cells are also relatively large, but are long and spindle shaped. Red blood cells and sperm are both exam- ples of small cells. Red blood cells appear round, while sperm cells are streamlined with long flagella. Cell shape is often directly related to function. Epithelial cells fit tightly together and cover large areas. Elongated muscle cells are capable of shortening during contraction. The red blood cells are small enough to fit through capillaries, and are actually biconcave in shape, which makes them flexible and increases surface area (not obvious to the students at this point). Sperm cells’ streamlined shape and flagella are directly related to efficient locomotion. M03_MARI5487_05_C03_pp008-012.indd 8 2/15/16 10:54 AM

  10. Page 10
    Read page 10 as text

    The sperm cells have visible projections (flagella), which are necessary for sperm motility. The function of sperm is to travel through the female reproductive system to reach the ovum in the uterine tubes. This requires motility. None of the cells lack a plasma membrane. Mature red blood cells have no nucleus. Nucleoli will probably be clearly visible in the epithelial cells, and possibly visible in the other nuclei. No. Identifiable organelles are not visible in most of these cells. Filaments may be visible in the smooth muscle preparations. The details of organelle structure are usually below the limit of resolution of the light microscope. Unless special stains are used, there is no way to see or distinguish the organelles at this level. Exercise 3 9 M03_MARI5487_05_C03_pp008-012.indd 9 2/15/16 10:54 AM

  11. Page 11
    Read page 11 as text

    10 R E V I E W S H E E T Anatomy of the Composite Cell 1. Define the following: organelles: “small organs”—The metabolic machinery of the cell organized to carry out specific activities for the cell as a whole cell: The structural and functional unit of all living things 2. Identify the following cell structures: plasma membrane 1. external boundary of cell; regulates flow of materials into and out of the cell lysosomes 2. contain digestive enzymes of many varieties; “suicide sacs” of the cell mitochondria 3. scattered throughout the cell; major sites of ATP synthesis microvilli 4. slender extensions of the plasma membrane that increase its surface area inclusions 5. stored glycogen granules, crystals, and pigments present in some cell types Golgi apparatus 6. membranous system consisting of flattened sacs and vesicles; packages proteins for export nucleus 7. control center of the cell; necessary for cell division and cell life centrioles 8. rod-shaped bodies that direct the formation of the mitotic spindle nucleolus 9. dense, darkly staining nuclear body; packaging site for ribosomes microfilaments 10. contractile elements of the cytoskeleton endoplasmic reticulum 11. membranous system that has “rough” and “smooth” varieties ribosomes 12. attached to membrane systems or scattered in the cytoplasm; synthesize proteins chromatin 13. threadlike structures in the nucleus; contain genetic material (DNA) peroxisome 14. site of free radical detoxification Name Lab Time/Date The Cell—Anatomy and Division E x E R c I S E 3 M03_MARI5487_05_C03_pp008-012.indd 10 2/15/16 10:54 AM

  12. Page 12
    Read page 12 as text

    Review Sheet 3 11 3. In the following diagram, label all parts provided with a leader line. Differences and Similarities in Cell Structure 4. For each of the following cell types, list (a) one important structural characteristic you observed in the laboratory and (b) write the function that the structure complements or ensures. squamous epithelium a. thin layer, flattened cells; fit closely together b. allows for easy diffusion and filtration sperm a. compact and streamlined; flagella b. able to propel itself in a short time smooth muscle a. non-striated, elongated, spindle-shaped b. provides a long axis for contraction red blood cells a. biconcave discs; lack nucleis; have few organelles b. easy gas exchange; more room for hemoglobin to transport oxygen Cytosol Smooth endoplasmic reticulum Golgi apparatus Mitochondria Peroxisome Rough endoplasmic reticulum Ribosomes Nuclear pore Nuclear envelope Lysosome Microtubule Intermediate filaments Nucleus Nucleolus Centrioles Microvilli M03_MARI5487_05_C03_pp008-012.indd 11 2/15/16 10:54 AM

  13. Page 13
    Read page 13 as text

    12 Review Sheet 3 Cell Division: Mitosis and Cytokinesis 5. Identify the three phases of mitosis shown in the following photomicrographs, and select the events from the key choices that correctly identify each phase. On the appropriate answer line, write the letters that correspond to these events. Key: a. Chromatin coils and condenses, forming chromosomes. b. The chromosomes (chromatids) are V-shaped. c. The nuclear membrane re-forms. d. Chromosomes stop moving toward the poles. e. Chromosomes line up in the center of the cell. f. The nuclear membrane fragments. g. The spindle forms. h. DNA synthesis occurs. i. Chromosomes first appear to be double. j. Chromosomes attach to the spindle fibers. k. The nuclear membrane(s) is absent. 1. Phase: Metaphase Events: e 2. Phase: Anaphase Events: b, d 6. What is the function of mitotic cell division? To increase the number of cells for growth and repair 3. Phase: Prophase Events: a, f, g, i, j, k For the letters used in the key above, list when those events would occur. c, h M03_MARI5487_05_C03_pp008-012.indd 12 2/15/16 10:55 AM

  14. Page 14
    Read page 14 as text

    13 4 E x E r c i s E Cell Membrane Transport Mechanisms This exercise has many parts to it. If students have had an introductory cell biology course, much of it should be review. Time Allotment: Diffusion of dye through agar gel—90 minutes Diffusion through nonliving membranes—120 minutes Diffusion through living membranes—25 minutes Filtration—10 minutes Observations for diffusion through living membranes and filtration can be done while waiting for the results of the other experiments. Multimedia Resources: See Appendix B for a list of multimedia resource distributors. A Journey to the Living Cell (CBS, 30 minutes, DVD) The Outer Envelope (WNS, 13 minutes, DVD) The Plasma Membrane and Cellular Transport (CVB: CD-ROM) Solutions: Agar Gel, 1.5% Weigh out 15 grams of dried agar. Slowly add 1 liter of distilled water while heating. Bring slowly to a boil, stirring constantly until the agar dissolves. For immediate use, allow the agar to cool to about 45°C. Pour into petri dishes to solidify. Refrigerate in an inverted position. If the plates are to be kept for a longer time (more than one day), autoclave the agar solution in the flask, pour into sterile petri plates, allow the agar to solidify, invert the plates, and store in a refrigerator. Benedict’s Solution • 173.0 grams sodium citrate • 100.0 grams sodium carbonate, anhydrous • 17.3 grams cupric sulfate (pure crystalline) Add the citrate and carbonate salts to 700–800 milliliters distilled water and heat to dissolve. Add the cupric sulfate to 100 milliliters distilled water and heat to dissolve. Cool the solutions and then com- bine. Add distilled water to make 1 liter of solution. Glucose, 40% For each 100 milliliters of solution, weigh out 40 grams of glucose and bring to 100 milliliters with distilled water. It may be necessary to heat the mixture to get the glucose into solution. Refrigerate when not in use. Lugol’s Iodine (IKI) • 20 grams potassium iodide • 4 grams iodine crystals Dissolve potassium iodide in 1 liter distilled water. Add the iodine crystals and stir to dissolve. Store in dark bottles. M04_MARI5487_05_C04_pp013-018.indd 13 2/15/16 11:02 AM

  15. Page 15
    Read page 15 as text

    14 Exercise 4 Physiologic Saline (Mammalian, 0.9%) Weigh out 9 grams of NaCl. Add water to a final volume of 1 liter. Make fresh immediately prior to experiment. Silver Nitrate (2.9 or 3.0%) Weigh out 2.9 grams (for 2.9%) or 3.0 grams (for 3.0%) of silver nitrate. Use caution; this is an oxidizing substance . Add distilled water to make 100 milliliters of solution. Store in light-resistant bottles. Make fresh for each use. Sodium Chloride (NaCl), 10% For each 100 milliliters of solution, weigh out 10 grams of NaCl and bring to 100 milliliters with dis- tilled water. It may be necessary to heat the mixture to get the NaCl into solution. Sodium Chloride (NaCl), 1.5% saline Weigh out 1.5 grams NaCl. Add distilled water to a final volume of 100 milliliters. Sucrose, 40% (with Congo Red Dye) For each 100 milliliters of solution, weigh out 40 grams of sucrose and bring to 100 milliliters with distilled water. Add 0.5 grams of Congo red dye. It may be necessary to heat the solution to get the sucrose into the solution. Refrigerate when not in use. Advance Preparation Note: This lab has many components. Either clearly designate supply areas for each part of the lab, or provide each lab group with its own set of supplies at the outset. The supplies for each part of the exercise are listed separately in case sections of the exercise are omitted. Some equipment is com- mon to several parts of the lab. 1. Set out slides and coverslips. Have compound microscopes available. 2. Diffusion of Dye Through Agar Gel . Set out 0.1M or 3.5% methylene blue solution (Carolina) and 0.1M or 1.6% potassium permanganate solution (Carolina), 1.5% agar plates (12 milliliters of 1.5% agar per plate, one per group), medicine droppers, and millimeter rulers. 3. Diffusion Through Nonliving Membranes . For each group, set out four dialysis sacs (WARD’S) or 10-centimeter lengths of dialysis tubing (Carolina), five 250-milliliter beakers, a wax marking pencil, 750 milliliters of distilled water, 10 milliliters of 10% NaCl solution , 10 milliliters of Congo red dye in 40% sucrose , 150 milliliters of 40% glucose solution , dropper bottles of Benedict’s solution (Carolina, or see above), silver nitrate , and Lugol’s iodine (Carolina, or see above), four test tubes, a test tube rack, test tube holder, small graduated cylinder, small funnel, hot plate, and balance. Dialysis sacs can be prepared from cut sections of dialysis tubing. Soak dialysis tubing in a beaker of water for about 15 minutes. Once dialysis tubing has been soaked, open it by rubbing it between the thumb and forefinger until the tubing material separates. Tie the ends with fine twine or close with dialysis tubing closures (Carolina). Small Hefty® “alligator” sandwich bags can also be used to make dialysis bags. 4. Diffusion Through Living Membranes . To prepare the solutions, add 5–10 drops of blood to test tubes containing: physiological saline (specimen 1), 1.5% NaCl (specimen 2), and distilled water (specimen 3). Drop 1–2 drop(s) of each solution on three separate slides and cover with coverslips. Set up demonstration area with compound microscopes and red blood cell suspensions. 5. Filtration . For each group, set out a funnel, filter paper, a flask, a dropper bottle of Lugol’s iodine , 50 mil- liliters of a solution of uncooked starch, powdered charcoal, and copper sulfate. Comments and Pitfalls 1. Caution students to keep careful track of time during the diffusion experiments. Lab timers might help. Suggestions for variables include T and different concentrations of solutions. 2. Dialysis sacs may leak. Check to see that they are tightly sealed. M04_MARI5487_05_C04_pp013-018.indd 14 2/15/16 11:02 AM

  16. Page 16
    Read page 16 as text

    Exercise 4 15 3. You may substitute Clinitest tablets for Benedict’s solution. 4. Silver nitrate will stain and possibly damage clothing. Warn students to be careful. 5. Note that the 40% glucose solution used in sac 1 of the osmosis experiment is not isoosmotic to the 10% NaCl solution in sac 3, so caution students about the types of conclusions they may draw from this experi- ment. Also, sometimes no glucose will be present in the beaker at the end of the hour. You may need to extend the time for this part of the experiment. 6. Emphasize the importance of labeling test tubes and slides. 7. Red blood cells in physiologic saline may begin to crenate as the slide begins to dry out. Encourage stu - dents to make their observations quickly. If there is still trouble with crenation, use a slightly hypotonic saline solution. Answers to Activity Questions Activity 1: Observing Diffusion of Dye Through Agar Gel (p. 30) 5. Potassium permanganate (MW 158) diffused more rapidly than methylene blue (MW 320). The smaller the molecular weight, the faster the rate of diffusion. The dye molecules moved because they possess kinetic energy. Heating the samples will increase the rate of diffusion for both samples by increasing the kinetic energy of the molecules. The greater the kinetic energy, the faster the diffusion. Activity 2: Observing Diffusion Through Nonliving Membranes (pp. 31–32) 4. After 1 hour, sac 1 (originally containing 40% glucose) should have gained weight. Water is moving into the sac by osmosis. Glucose is still present in the sac, and a small amount of glucose may also be present in the beaker. If the Benedict’s test is positive, glucose was able to pass through the dialysis membrane. 5. There should be no net weight change in sac 2. Since the concentrations of glucose and water are the same on both sides of the membrane, there is no net movement of water or glucose. 6. Sac 3 will increase in weight, perhaps only by a small amount. There has been a net movement of water into the sac, and the weight of the water was not completely offset by the movement of the NaCl out of the sac. The solution in beaker 3 reacts with silver nitrate, indicating the presence of chloride in the bea- ker. Net dialysis of NaCl occurred. 7. There should be an increase in weight in sac 4. The water color did not turn pink; the dye was not able to diffuse out of the sac. The Benedict’s test for sugar was negative. Sucrose did not diffuse from the sac to the beaker. The dye and sucrose molecules are too large to diffuse through the pores in the membrane or their rate of diffusion is too slow given the allowed time. 8. Net osmosis occurred in situations 1 and 4; net simple diffusion occurred in 1 and 3. Water molecules are very small and move quickly down a concentration gradient. Na+ and Cl– in solu - tion behave like slightly larger molecules but are smaller than glucose molecules, which move slowly, if at all, through the dialysis tubing. (See item 5 in Comments and Pitfalls.) Note: Students may only be able to conclude that Na+ and Cl– in solution and water molecules are small, and glucose and Congo red dye molecules are larger, or that Na+ and Cl– in solution and water and glucose molecules are smaller than sucrose molecules. The dialysis sac is often compared to the plasma membrane of the cell. M04_MARI5487_05_C04_pp013-018.indd 15 2/15/16 11:02 AM

154 more pages in the full document

Unlock it once and it stays in your library, ready to chat with or turn into flashcards.

Unlock the full document

More Anatomy and Physiology study materials

See all

Study this document with CramX

Once it is in your library, every tool can work from it.