Science Skills and Processes

A student wants to perform an investigation to determine the heart rate of a rabbit. The teacher tells her the heart rate should be about 100 beats per minute. How could this information affect the investigation? A. It could introduce bias. B. It could remove experimental error. C. It could increase the accuracy of the data. D. It could reduce the number of measurements needed.

A scientist is performing an investigation funded by a company. Which of these would be least likely to produce biased data? A. making the results please the company paying for the research B. being open minded and honest throughout the research project C. using only the data that supports the hypothesis D. using personal opinions to decide the results of the research

A student washes her hands with antibacterial soap and water. Then she touches the agar in a petri dish with her thumb. The agar contains nutrients that support the growth of bacteria. Other students repeat the procedure after washing their hands with three different kinds of antibacterial soap. The petri dishes are kept warm overnight to allow bacteria to grow. The next day the students count the number of bacterial colonies in each dish. Which of these questions are the students most likely trying to answer? A. How long does it take soap to kill bacteria? B. Which soap is most effective in killing bacteria? C. Which nutrients are necessary to grow bacteria? D. How many bacteria are on the average thumb?

The breathing rate of a goldfish can be measured by the number of times the goldfish opens its mouth. In an experiment, students placed a goldfish in a container of water at 26°C and counted the number of times the fish opened its mouth. They gradually lowered the water temperature and counted the number of times the fish opened its mouth at 20°C, 14°C, 8°C, and 2°C. Which of these procedures would be a good control for this experiment? A. Use a different kind of fish for each water temperature. B. Determine the breathing rate of a goldfish kept at a constant 26°C. C. Put the goldfish in 2°C water and then increase the temperature. D. Repeat the experiment using a different species of goldfish.

A group of students studied the effect of light intensity on the rate of a cell process in Elodea plants. The students exposed Elodea plants to different light intensities. A gas was produced by the cell process. The amount of this gas was measured. The rate of the cell process was determined by the amount of gas produced. Which of these is the independent variable in this experiment? A. rate of cell process B. volume of gas C. size of Elodea plant D. intensity of light