Experiments questions lab

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1 Name: Date: 1. To locate a specimen on a prepared slide with a compound microscope, a student should begin with the low-power objective rather than the high-power objective because the A. field of vision is smaller under low power than under high power B. field of vision is larger under low power than under high power C. specimen does not need to be stained for observation under low power but must be stained for observation under high power D. portion of the specimen that can be observed under low power is less than the portion that can be observed under high power 2. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. Use one or more complete sentences to answer each question. When a drug manufacturer develops a new drug to treat some form of disease, the drug should be tested to ensure that it does what it is supposed to do. Usually, the drug is tested on animals and, if these tests are successful, it is then tested on humans. A drug called Lowervil was developed by a drug company to lower blood pressure. Lowervil has been tested successfully on animals, and the drug company is now ready to test it on humans. The drug company claims that on dose of Lowervil per day will decrease blood pressure in individuals experiencing high blood pressure. A research has been hired to determine whether or not Lowervil lowers blood pressure. Answer the following questions related to the experimental testing of the new drug Lowervil. How should the experimental group and control group be treated differently? 3. Why would it be important to use a large number of people in this experiment? page 1

2 4. A coverslip should be used for preparing a A. frog for dissection B. solution of iodine for food testing C. wet mount of elodea (a simple plant) D. test to determine the ph of a solution 5. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. An investigation was performed to determine the effects of enzyme X on three different disaccharides (double sugars) at 37 C. Three test tubes were set up as shown in the diagram below. At the end of 5 minutes, the solution in each test tube was tested for the presence of disaccharides (double sugars) and monosaccharides (simple sugars). The results of these tests are shown in the table below. Test Tube 1 Test Tube 2 Test Tube 3 Monosaccharide not present not present present Disaccharide present present not present With only the materials list supplied below and common laboratory equipment, design an investigation that would show how a change in ph would affect the activity of enzyme X. Your design need only include detailed procedure and a data table. Enzyme X Sugar C solution Materials Indicators Substances of various ph values vinegar (acidic) water (neutral) baking soda (basic) 6. State one safety precaution that should be used during the investigation. page 2

3 7. A student designed an investigation to determine the effect of temperature on the rate of seed germination. The student placed moist filter paper in each of four culture dishes. Ten bean seeds were placed on the filter paper in each dish. The four dishes were numbered and placed in the dark at different temperatures as follows: Dish 1: 10 C, Dish 2: 15 C, Dish 3: 20 C, Dish 4: 25 C. The total number of germinated seeds in each culture dish was counted each day for two weeks. Which data table is best for recording the results of this investigation? A. B. C. D. 8. A student wanted to determine if slugs preferred green leaf lettuce leaves over purple cabbage leaves for food. Pieces of both leaves were cut. One piece of each type of leaf and one slug were placed in each of ten containers. After three days, the surface area of each leaf section was measured and the results were recorded in a data table. State one reason that the results of this experiment might be considered invalid. 9. An experimental design included references from prior experiments, materials and equipment, and step-by-step procedures. What else should be included before the experiment can be started? A. a set of data B. a conclusion based on data C. safety precautions to be used D. an inference based on results page 3

4 10. Many people who are in favor of alternative medicine claim that large doses of vitamin C introduced into a vein speed up the healing of surgical wounds. Describe an experiment to test this hypothesis. Your answer must include at least: the difference between the experimental group of subjects and the control group two conditions that must be kept constant in both groups data that should be collected an example of experimental results that would support the hypothesis 11. Base your answer(s) to the following question(s) on the information, diagram, table, and on your knowledge of biology. A student wanted to test the hypothesis that rooting hormones will stimulate the production of new roots at a faster rate than would take place without rooting hormones. Two stem cuttings of equal length, similar to the one shown below, were taken from a rose, a begonia, and a geranium plant. The cut end of one cutting from each plant was dipped into the hormone and then planted in wet sand. The other cutting from each plant was planted in wet sand without dipping it into the hormone. All cuttings were maintained in identical environmental conditions. At the end of 4 weeks, all the cuttings were removed from the sand and the lengths of the roots that had developed were measured. The results are summarized in the data table below. Describe one way the student could make the experiment more valid. page 4

5 12. Base your answer(s) to the following question(s) on the provided information. 13. State two factors that should be kept constant. Acid rain can have a ph between 1.5 and 5.0. The effect of acid rain on the environment depends on the ph of the rain and the characteristics of the environment. It appears that acid rain has a negative effect on plants. The scale below shows the ph of normal rain. Provide the information requested below that should be included in a research plan to test the effect of ph on the early growth of bean plants in the laboratory. Identify the independent variable. 14. Which structure is best observed using a compound light microscope? A. a cell B. a virus C. a DNA sequence D. the inner surface of a mitochondrion page 5

6 15. Base your answer(s) to the following question(s) on the information, diagram, data table, and on your knowledge of biology. A student conducted an investigation to determine the effect of various environmental factors on the rate of transpiration (water loss through the leaves) in plants. The student prepared 4 groups of plants. Each group contained 10 plants of the same species and leaf area. Each group was exposed to different environmental factors. The apparatus shown in the diagram was constructed to measure water loss by the plants over time in 10-minute intervals for 30 minutes. The results are shown in the data table. Using the information in the data table, construct a line graph on the grid, following the directions. The data for fan and mist conditions have been plotted for you. page 6

7 16. On a television talk show, a guest claims that people who exercise vigorously for 15 minutes or more every day are able to solve math problems more rapidly than people who have no vigorous exercise in their daily routine. Describe a controlled experiment that could be conducted to test this claim. In your description be sure to: state the purpose of the experiment state why the sample to be used should be large describe how the experimental group will be treated and how the control group will be treated state the specific data to be collected during the experiment state one way to determine if the results support the claim 18. An experiment was designed to see what effects ibuprofen would have on laboratory mice. Large numbers of male mice and an equal number of female mice were used in this investigation. The male mice were placed in an area with food and water. The female mice were placed in a separate area of the same size. The female mice were given additional food and water. The males were each given 100 milligrams of ibuprofen each day, mixed with their food, and the females were each given 50 milligrams of ibuprofen each day, mixed with their food. Identify two errors in the design of this investigation. 19. The photos below show two red onion cells viewed with the high power of a compound light microscope. Describe the steps that could be used to make cell A resemble cell B using a piece of paper towel and an eyedropper or a pipette without removing the coverslip. 17. A scientist is planning to carry out an experiment on the effect of heat on the function of a certain enzyme. Which would not be an appropriate first step? A. doing research in a library B. having discussions with other scientists C. completing a data table of expected results D. using what is already known about the enzyme 20. Researchers performing a well-designed experiment should base their conclusions on A. the hypothesis of the experiment B. data from repeated trials of the experiment C. a small sample size to insure a reliable outcome of the experiment D. results predicted before performing the experiment page 7

8 21. The diagram below illustrates the result of growing a garlic bulb in a cup of distilled water over five days. Design an experiment consisting of a control and three different experimental groups to test the prediction, Garlic grows better as the salt concentration of the solution in which it is grown increases. In your answer, be sure to: describe the control to be used in the experiment describe the difference between the three experimental groups state one type of measurement that should be made to determine if the prediction is accurate 22. The drugs usually used to treat high blood pressure do not affect blood vessels in the lungs. Bosentan is a new drug being studied as a treatment for high blood pressure in the lungs. In an experiment, patients treated with bosentan showed an improvement in the distance they could walk without fatigue within 12 weeks. Design an experiment to test the effectiveness of bosentan as a drug to treat high blood pressure in the lungs. In your answer be sure to: state the hypothesis your experiment will test state how the control group will be treated differently from the experimental group state two factors that must be kept the same in both the experimental and control groups state the type of data that should be collected to determine if the hypothesis is supported describe one example of experimental results that would support the prediction page 8

9 23. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. 24. The diagram below shows how a coverslip should be lowered onto some single-celled organisms during the preparation of a wet mount. Paper chromatography can be used to investigate evolutionary relationships. Leaves from a plant were ground and mixed with a solvent. The mixture of ground leaves and solvent was then filtered. Using a toothpick, twenty drops of the filtrate (material that passed through the filter) were placed at one spot on a strip of chromatography paper. This procedure was repeated using leaves from three other species of plants. A separate strip of chromatography paper was prepared for each plant species. Each of the four strips of chromatography paper was placed in a different beaker containing the same solvent for the same amount of time. One of the laboratory setups is shown below. Why is this a preferred procedure? A. The coverslip will prevent the slide from breaking. B. The organisms will be more evenly distributed. C. The possibility of breaking the coverslip is reduced. D. The possibility of trapping air bubbles is reduced. State one reason for using a new toothpick for the filtrate from each plant. page 9

10 25. An experiment was carried out to determine which mouthwash was most effective against bacteria commonly found in the mouth. Four paper discs were each dipped into a different brand of mouthwash. The discs were then placed onto the surface of a culture plate that contained food, moisture, and bacteria commonly found in the mouth. The diagram below shows the growth of bacteria on the plate after 24 hours. 26. Plants respond to their environment in many different ways. Design a controlled experiment to test the effect of one environmental factor (such as light, acidity of precipitation, etc.) on some aspect of plant growth. In your experimental design be sure to: state the hypothesis list the steps of the procedure identify the control setup for the experiment include an appropriate data table with column headings for the collection of data identify the independent variable in the experiment Which change in procedure would have improved the experiment? A. using a smaller plate with less food and moisture B. using bacteria from many habitats other than the mouth C. using the same size paper discs for each mouthwash D. using the same type of mouthwash on each disc 27. To test the effect of hormones on plant growth, six potted plant seedlings of the same species were measured and then sprayed with auxin (a growth hormone). After four weeks of growth under ideal conditions, the plants were measured again. To set up a proper control for this experiment, the investigator should A. spray the same plants with different amounts of auxin B. spray auxin on six plant seedlings of the same species and grow them in the dark for four weeks C. wash the auxin off three of the plants after two weeks D. grow another six plant seedlings of the same species under the same conditions, spraying them with distilled water only page 10

11 28. State two safety procedures that should be followed when conducting an experiment that involves heating protein in a test tube containing water, an acid, and a digestive enzyme. 31. The concentration of salt in water affects the hatching of brine shrimp eggs. Brine shrimp eggs will develop and hatch at room temperature in glass containers of salt solution. Describe a controlled experiment using three experimental groups that could be used to determine the best concentration of salt solution in which to hatch brine shrimp eggs. Your answer must include at least: a description of how the control group and each of the three experimental groups will be different 29. A television advertisement claims that a certain brand of cough drop reduces coughing for 8 hours. Describe an investigation that could be used to determine if this claim is valid. In your answer, include at least a description of: the treatment to be given to the experimental group the treatment to be given to the control group the data to be collected when the data should be collected one observation that would lead to the conclusion that the claim is valid two conditions that must be kept constant in the control group and the experimental groups data that should be collected one example of experimental results that would indicate the best concentration of salt solution in which to hatch brine shrimp eggs 32. Base your answer(s) to the following question(s) on the data table below and on your knowledge of biology. The table contains information about glucose production in a species of plant that lives in the water of a salt marsh. 30. A student hypothesizes that the pulse rate of a person and background music that is playing are related. The student designs an experiment to test this hypothesis. What would be an appropriate control for this experiment? Temperature ( C) Glucose Production (mg/hr) What evidence from the data table shows that a salt-marsh plant is sensitive to its environment? page 11

12 33. At which temperature would the plants most likely use the greatest amount of carbon dioxide? 36. Which level of the energy pyramid below would contain the plant species of this salt marsh? A. 10 C B. 20 C C. 30 C D. 40 C A. A B. B C. C D. D 34. How much oxygen will plants that live in water at 10 C most likely produce? A. twice the amount of oxygen produced at 20 C B. the same amount of oxygen produced at 40 C C. the most oxygen produced at any temperature D. more oxygen than is produced at 30 C 37. A scientist wants to determine the best conditions for hatching brine shrimp eggs. In a laboratory, brine shrimp hatch at room temperature in glass containers of salt water. The concentration of salt in the water is known to affect how many brine shrimp eggs will hatch. Design an experiment to determine which of three saltwater concentrations (2%, 4%, or 6%) is best for hatching brine shrimp eggs. In your experimental design, be sure to: 35. State one possible reason for the change in glucose production when the temperature was increased from 30 C to 40 C. state how many containers to use in the experiment, and describe what would be added to each container in addition to the eggs state two factors that must be kept constant in all the containers state what data must be collected during this experiment state one way to organize the data so that they will be easy to analyze describe a result that would indicate the best salt solution for hatching brine shrimp eggs page 12

13 38. While viewing a specimen under high power of a compound light microscope, a student noticed that the specimen was out of focus. Which part of the microscope should the student turn to obtain a clearer image under high power? A. eyepiece B. coarse adjustment C. fine adjustment D. nosepiece 40. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. A biology student was given three unlabeled jars of pond water from the same source, each containing a different type of mobile unicellular organism: euglena, ameba, and paramecium. The only information the student has is that the ameba and paramecium are both heterotrophs and the euglena can be either heterotrophic or autotrophic, depending on its environment. Which procedure and resulting observation would help identify the jar that contains the euglena? A. Expose only one side of each jar to light. After 24 hours, only in the jar containing euglena will most of organisms be seen on the darker side of the jar. 39. How much water should be removed from the graduated cylinder shown below to leave 5 milliliters of water in the cylinder? B. Expose all sides of each jar to light. After 48 hours, the jar with the highest dissolved carbon dioxide content will contain the euglena. C. Over a period of one week, determine the method of reproduction used by each type of organism. If mitotic cell division is observed, the jar will contain euglena. D. Prepare a wet-mount slide of specimens from each jar and observe each slide with a compound light microscope. Only the euglena will have chloroplasts. A. 6 ml B. 7 ml C. 11 ml D. 12 ml page 13

14 41. A certain plant has white flower petals and it usually grows in soil that is slightly basic. Sometimes the plant produces flowers with red petals. A company that sells the plant wants to know if soil ph affects the color of the petals in this plant. Design a controlled experiment to determine if soil ph affects petal color. In your experimental design be sure to: state the hypothesis to be tested in the experiment state one way the control group will be treated differently from the experimental group identify two factors that must be kept the same in both the control group and the experimental group identify the dependent variable in the experiment state one result of the experiment that would support the hypothesis 43. Students were asked to determine if they could squeeze a clothespin more times in a minute after resting than after exercising. An experiment that accurately tests this question should include all of the following except A. a hypothesis on which to base the design of the experiment B. a large number of students C. two sets of clothespins, one that is easy to open and one that is more difficult to open D. a control group and an experimental group with equal numbers of students of approximately the same age 42. An experiment was carried out to determine how competition for living space affects plant height. Different numbers of plants were grown in three pots, A, B, and C. All three pots were the same size. The data collected are shown in the table below. 44. Which statement best describes a controlled experiment? A. It eliminates the need for dependent variables. Analyze the experiment that produced the data shown in the table. In your answer be sure to: state a hypothesis for the experiment identify one factor, other than pot size, that should have been kept the same in each experimental group identify the dependent variable state whether the data supports or fails to support your hypothesis and justify your answer B. It shows the effect of a dependent variable on an independent variable. C. It avoids the use of variables. D. It tests the effect of a single independent variable. page 14

15 45. Base your answer(s) to the following question(s) on the diagram below and on your knowledge of biology. The diagram shows the results of a technique used to analyze DNA. 47. Base your answer(s) to the following question(s) on the information and data table below and on your knowledge of biology. A student studied the location of singlecelled photosynthetic organisms in a lake for a period of several weeks. The depth at which these organisms were found at different times of the day varied greatly. Some of the data collected are shown in the table below. This laboratory technique is known as A. gel electrophoresis B. DNA replication C. protein synthesis D. genetic recombination Which materials would the student most likely have used in this investigation? A. microscope, pipette, and slides with coverslips B. graduated cylinder, triple-beam balance, and chromatography paper C. thermometer, electric balance, and biological stains D. computer, ph paper, and gel electrophoresis apparatus 46. State one specific way the results of this laboratory technique could be used. page 15

16 48. A student prepared a slide of pollen grains from a flower. First the pollen was viewed through the low-power objective lens and then, without moving the slide, viewed through the high- power objective lens of a compound light microscope. Which statement best describes the relative number and appearance of the pollen grains observed using these two objectives? A. low power: 25 small pollen grains high power: 100 large pollen grains 50. Paper chromatography is a laboratory technique that is used to A. separate different molecules from one another B. stain cell organelles C. indicate the ph of a substance D. compare relative cell sizes B. low power: 100 small pollen grains high power: 25 large pollen grains C. low power: 25 large pollen grains high power: 100 small pollen grains D. low power: 100 large pollen grains high power: 25 small pollen grains 49. Which laboratory procedure is represented in the diagram below? A. placing a coverslip over a specimen B. removing a coverslip from a slide C. adding stain to a slide without removing the coverslip D. reducing the size of air bubbles under a coverslip page 16

17 51. Base your answer(s) to the following question(s) on the information and data table below and on your knowledge of biology. 52. A laboratory technique is illustrated in the diagram below. The table shows data collected on the ph level of an Adirondack lake from 1980 to Lake ph Level Year ph Level This technique is used to A. determine volume B. separate molecules in a mixture C. measure length D. analyze data from an experiment 53. Which activity might lead to damage of a microscope and specimen? Identify one factor that should have been kept constant each time water samples were collected from the lake. A. cleaning the ocular and objectives with lens paper B. focusing with low power first before moving the high power into position C. using the coarse adjustment to focus the specimen under high power D. adjusting the diaphragm to obtain more light under high power page 17

18 54. Which statement about the use of independent variables in controlled experiments is correct? A. A different independent variable must be used each time an experiment is repeated. B. The independent variables must involve time. C. Only one independent variable is used for each experiment. D. The independent variables state the problem being tested. 56. Many plants can affect the growth of other plants near them. This can occur when one plant produces a chemical that affects another plant. Design an experiment to determine if a solution containing ground-up goldenrod plants has an effect on the growth of radish seedlings. In your experimental design be sure to: state a hypothesis to be tested describe how the experimental group will be treated differently from the control group explain why the number of seedlings used for the experiment should be large identify the type of data that will be collected describe experimental results that would support your hypothesis 55. A scientist was investigating why a particular tree species grows only in a specific environment. To determine physical conditions the tree species needs to survive, an appropriate study should include 57. Base your answer(s) to the following question(s) on the diagram below that illustrates the results of a laband on your knowledge of biology A. the identification of organisms in the food web in that environment B. an analysis of the arrangement of the leaves on the trees C. the identification of all tree species in the area D. an analysis of the soil around the tree The results of which laboratory technique are represented in the diagram? A. chromatography B. manipulation of genes C. genetic engineering D. gel electrophoresis page 18

19 58. Base your answer(s) to the following question(s) on the diagram below and on your knowledge of biology. The diagram illustrates what happens when a particular solution is added to a wet-mount slide containing red onion cells being observed using a compound light microscope. 60. Plants respond to their environment in many different ways. Design an experiment to test the effects of one environmental factor, chosen from the list below, on plant growth. Acidity of precipitation Temperature Amount of water In your answer, be sure to: To observe the cells on this slide it is best to start out using the A. high-power objective and focus using the coarse adjustment, only B. low-power objective and focus using the fine adjustment, only C. high-power objective and focus using the fine adjustment identify the environmental factor you chose state one hypothesis the experiment would test state how the control group would be treated differently from the experimental group state two factors that must be kept the same in both the experimental and control groups identify the independent variable in the experiment label the columns on the data table below for the collection of data in your experiment Environmental factor: D. low-power objective and focus using the coarse adjustment 59. In some people, the lack of a particular enzyme causes a disease. Scientists are attempting to use bacteria to produce this enzyme for the treatment of people with the disease. Which row in the chart below best describes the sequence of steps the scientists would most likely follow? Row Step A Step B Step C Step D (1) identify the gene insert the gene into remove the gene extract the enzyme a bacterium (2) insert the gene into identify the gene remove the gene extract the enzyme a bacterium (3) identify the gene remove the gene insert the gene into extract the enzyme a bacterium (4) remove the gene extract the enzyme identify the gene insert the gene into a bacterium A. (1) B. (2) C. (3) D. (4) page 19

20 61. A chromatography setup is shown below. 62. Base your answer(s) to the following question(s) on the information and diagram below and on your knowledge of biology. A wet mount of red onion cells as seen with a compound light microscope is shown below. Identify one error in the setup. Which diagram best illustrates the technique that would most likely be used to add salt to these cells? A. B. C. D. page 20

21 63. Which substance would most likely be used to return the cells to their original condition? 65. A wet-mount slide preparation of a specimen is stained in order to A. starch indicator B. dialysis tubing C. glucose indicator solution D. distilled water A. eliminate some organelles B. make cell structures more visible C. use the high-power lens D. remove water from the slide 64. Base your answer to the following question on the information below and on your knowledge of biology. Help for Aging Memories As aging occurs, the ability to form memories begins to decrease. Research has shown that an increase in the production of a certain molecule, BDNF, seems to restore the processes involved in storing memories. BDNF is found in the central nervous system and seems to be important in maintaining nerve cell health. Researchers are testing a new drug that seems to increase the production of BDNF. Design an experiment to test the effectiveness of the new drug to increase the production of BDNF in the brains of rats. In your answer, be sure to: state the hypothesis your experiment will test describe how the control group will be treated differently from the experimental group 66. A student conducted an experiment to determine if listening to different types of music would affect pulse rate. She thought that pulse rate would change with different types of music. Each person participating in her experiment listened to seven different selections of music for 30 seconds each. The pulse rates were taken after each 30-second interval of music. Based on her experiment, the student concluded that a person s pulse rate changed when listening to different types of music. The component missing from this experiment is a A. prediction B. hypothesis C. control group D. research plan identify two factors that must be kept the same in both the experimental and control groups identify the dependent variable in your experiment page 21

22 67. An experiment was carried out to determine whether drinking caffeinated soda increases pulse rate. The pulse rates of two groups of people at rest were measured. Group A was then given caffeinated soda and group B was given caffeine-free soda. One hour after drinking the soda, the pulse rates were measured. The participants in the experiment were all the same age, and they were all given the same amount of soda. The dependent variable in this experiment is the A. type of soda given to each group B. amount of soda given to each group C. pulse rate of each group 69. A company that manufactures a popular multivitamin wanted to determine whether their multivitamin had any side effects. For its initial study, the company chose 2000 individuals to take one of their multivitamin tablets per day for one year. Scientists from the company surveyed the participants to determine whether they had experienced any side effects. The greatest problem with this procedure is that A. only one brand of vitamin was tested B. the study lasted only one year C. the sample size was not large enough D. no control group was used D. age of participants in each group 68. Base your answer to the following question on the information below and on your knowledge of biology. A student states that exercise will affect the number of times a person can squeeze a clothespin in a certain amount of time. An experiment is carried out to test this hypothesis. One group of ten students sits quietly before squeezing a clothespin as many times as possible during a one-minute interval. A second group of ten students does 25 jumping jacks before squeezing a clothespin as many times as possible during a one-minute interval. State one way the experiment could be improved in order to increase the validity of the results. 70. Base your answer to the following question(s) on the information below and on your knowledge of biology. An investigation is carried out to determine the effect of exercise on the rate at which a person can squeeze a clothespin. In this investigation, the independent variable is the A. control B. exercise C. rate of squeezing D. number of participants page 22

23 71. Part of a laboratory procedure is shown in the diagram below. 73. The materials represented in the diagram below were used in a laboratory activity. This setup would most likely be involved in a procedure to A. stain specimens while making a wet mount B. test for the presence of glucose using an indicator C. separate pigments in a mixture D. determine the ph of solutions These materials were used to carry out the technique known as A. DNA staining B. genetic engineering C. paper chromatography 72. The diagram below shows a student heating some test tubes with chemicals in them during a laboratory activity. D. glucose testing 74. A coverslip should be slowly lowered from a 45 angle onto a slide in order to A. prevent the slide from being scratched B. stop the loss of water from under the coverslip Explain why putting stoppers in the test tubes could be dangerous. C. ensure that the specimen being viewed will stay alive D. reduce the formation of air bubbles page 23

24 75. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. A student grew ten tomato plants from seed. After three weeks, the heights of the ten plants were measured in centimeters (cm). The results are shown below. Tomato plant A = 5 cm Tomato plant B = 3 cm Tomato plant C = 3 cm Tomato plant D = 3 cm Tomato plant E = 5 cm Tomato plant F = 9 cm Tomato plant G = 7 cm Tomato plant H = 5 cm Tomato plant I = 3 cm Tomato plant J = 7 cm Organize the data by completing both columns in the data table below, so that the height of the plants increases from the top to the bottom of the table. Height of Tomato Plants After Three Weeks Height of Plant (cm) Number of Tomato Plants 76. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. DNA samples were taken from three different species and used to determine the amino acid sequence for a portion of a particular protein. The amino acids were then compared in order to determine which species were most closely related. Some of the information is shown on the table below. Species A Species B Species C DNA base sequence mrna base sequence amino acid sequence DNA base sequence mrna base sequence amino acid sequence DNA base sequence mrna base sequence amino acid sequence GAC CUG LEU GAC LEU GAC CUG LEU TGA ACU THR AGA UCU TGC THR CTC GAG CTT GAA CAC GUG VAL CAC GUG VAL CAC VAL CTC GLU TGA ACU TGA ACU THR AGA UCU SER In an experiment to test the effect of exercise on the number of times a clothespin can be squeezed in 1 minute, the dependent variable would be the A. test subject B. amount of exercise C. number of squeezes D. clothespin page 24

25 77. Base your answer(s) to the following question(s) on the information below and on your knowledge of biology. A student wants to bake the biggest loaf of bread in the local baking contest. Each contestant must use the same amounts of flour, sugar, and yeast, but is allowed to vary the type of sugar. Yeast is a microorganism that carries out cellular respiration, which produces carbon dioxide, making the bread rise. The student designs an experiment using the setup below to determine which sugar source (glucose, sucrose, or fructose) will cause the yeast to produce the most carbon dioxide and therefore, the biggest loaf of bread. A B C Describe the specific type of data to be collected. 78. In addition to bottles A, B, and C, the student sets up a control bottle, D. Write the contents of bottle D on the blank line on the diagram below. page 25