Scientific Method
A diagram of the actual size of a peppered moth wingspan is shown below. An estimated length of the wingspan could be
1. 3 centimeters
A water plant placed in bright light gives off bubbles. A student notes placing the light at different distances from the plant causes the rate of bubbling to vary. The student designs an experiment to investigate the light intensity on the rate of bubble production. An appropriate control for this experiment would be
1. A plant at a fixed distance from the light source
When a sunfish respirates, its gills open and close. The more often the gills and close, the higher the rate of respiration. Mariel counted the number of gill covers of a sunfish opened and closed during 1-minute intervals at different temperatures. She recorded the results in a data table. If Mariel constructed a graph using the information above, which title should she use?
1. The Effect of Temperature on Rate of Respiration in Sunfish
Graphs of the data from laboratory investigations are used to
1. observe general trends in the data
A student counted the total number of leaves in a group of duckweed plants over a 5-day period. The data collected are shown in the table. The time it takes for the number of leaves to increase from 15 to 30 is about
2. 2.3 days
A class is recording pulse rates of the students in a data table like the one shown below. One student checks his pulse and counts 23 beats over a time interval of 20 seconds. In which row in the data table should the pulse rate of this student be recorded?
2. B
A student wants to test the hypothesis that an acidic environment will decrease enzyme activity. In the experiment, the student used an enzyme that breaks down hydrogen peroxide into water and bubbles of oxygen. To test the hypothesis, the student should collect data on the number of oxygen bubbles produced at different
2. pH levels
In an investigation to determine the change in heart rate with increased activity, a biology teacher asked students to take their pulses immediately before and immediately after exercising for 2 minutes. The data showed an average heart rate of 72 beats per minute before exercising and 90 beats per minute after exercising. If a valid conclusion is to be made from the results of this investigation, which assumption must be made?
3. Each student exercised with the same intensity.
Base your answer to the question on the information and diagram below and on your knowledge of biology. In an experiment, students placed a dialysis bag containing 100 mL of a starch-water mixture in a beaker of water, as shown below. They left the setup until class the next day, when they removed the dialysis bag and measured the volume of the contents. They found that there were now 125 mL of the starch-water mixture. To measure the volume of the starch-water mixture in the dialysis bag, the students should have used a
3. Graduated cylinder
In an experiment, students study how much salt can be dissolved in a cup of water at varying temperatures. Which factor should be held constant in this experiment?
3. The amount of water in the cup
Base your answer to the question on the information and graph below and on your knowledge of biology. Students were asked to design a lab that investigated the relationship between exercise and heart rate. Heart rate was determined by recording the pulse rate in beats per minute. The students hypothesized that increased exercise results in an increased heart rate. The class results for the experiment are shown in the graph below. Which statement is best supported by the graph?
3. While exercising, the highest average pulse rate was 150; before exercising, the average pulse rate was 65.
How much water should be added to the graduated cylinder shown below to increase the volume to 15 milliliters?
4. 4 mL
Base your answer to the question on the information and graph below and on your knowledge of biology. Students were asked to design a lab that investigated the relationship between exercise and heart rate. Heart rate was determined by recording the pulse rate in beats per minute. The students hypothesized that increased exercise results in an increased heart rate. The class results for the experiment are shown in the graph below. Students in a different science class carried out the same experiment. The data they obtained did not support the hypothesis that increased exercise results in increased heart rate. The most scientifically sound way to deal with this situation is to
4. Ask students in a third class to do the experiment and see if their results support the hypothesis
Which safety precaution is recommended when a liquid is being heated in a test tube?
4. Wear goggles and a laboratory apron.
The data table contains information on the growth of eight white pine trees, planted in eight different locations, after a period of time. Which statement is true based on the data in the table?
4. White pines can grow in acidic soil.
