Education Transformation Office (ETO) 8 th Grade Unit # 1 Assessment 1. A student wants to find out if temperature affects the behavior of goldfish. He has four bowls and 20 goldfish. Which of the following experiments should he do? 2. Jorge wants to know whether music affects plant growth. He puts two identical plants in separate rooms. One room is sunny and has a stereo playing rock music all day. The other room is quiet and dark. He gives both plants the same amount of water. After two weeks he compares the plants. The plant in the room with music is green and growing. Leaves on the plant in the other room are turning yellow. He concludes that music helps plants grow. What makes his scientific explanation weak? A. He did not have a testable hypothesis. B. He did not use two different plants in each room. C. He did not add fertilizer to the plants in either room. D. He had more than one variable in his experimental conditions. Page 1 Unit Assessment #1
3. On his voyage on the HMS Beagle, Darwin saw fossils of giant sloths whose bones resembled bones of living sloths, but were much larger in size. Darwin hypothesized that the fossilized sloths were related to sloths alive today. This hypothesis was based on: A. investigations using observation and inference. B. experimentation using controlled variables C. creating models to create a theory D. making predictions 4. Given that scientific evidence either supports or does not support a hypothesis, what can you infer from the following statement? A hypothesis can never be proved. A. The only way to prove a hypothesis is to test it many times. B. Even if the results of a test do not support the hypothesis, the hypothesis cannot be disproved. C. Scientists are always discovering new information, which may affect or change an accepted hypothesis. D. It only takes one supported hypothesis to formulate a scientific theory. 5. A student wants to shorten the ripening time for tomatoes. He predicts that the more water the seedlings receive, the faster the tomatoes will ripen. He grows 20 tomato plants in a garden in full sunlight that has dry soil, and 20 tomato plants in the same garden where there is more moisture in the soil. He records the time it takes for fruit to develop and ripen on the plants in each location. What is test variable (independent variable) in this experiment? A. The time it takes for the fruit to develop and ripen. B. The tomato seedlings at different stages of development. C. The amount of sunlight each plant receives. D. The amount of moisture each plant receives. 6. A student conducted an experiment to determine how the mass of a plastic disk affects its motion. The student pushed five similar plastic disks, each with a different mass, across a wooden floor. The student recorded the distance that each disk traveled and then repeated the experiment 5 more times. The student concluded that there was no relationship between mass and the distance traveled by the disks. Which of these best describes an error in the experiment? A. The student performed too few trials. B. The student should have used disks that were the same mass. C. The student should have pushed the disks across different surfaces. D. The student failed to control the amount of force applied. 7. A student studying spiders creates the data table shown below. What conclusion can be drawn based on this information? A. Web spiders are larger than hunting spiders. B. Wolf spiders are the largest of these spiders. C. Hunting spiders have warning color patterns. D. Jumping spiders are faster than yellow garden spiders. Page 2 Unit Assessment #1
8. Isabella carried out an experiment to test her hypothesis. She repeated the experiment three times. None of the experiments supported her hypothesis. What should she do? A. Repeat the experiment again. B. Revise her hypothesis and test the new hypothesis. C. Use her friend s data because it supports her hypothesis. D. Have someone watch her to make sure she is following the steps properly. 9. The purpose of repeated experimental trials is to: A. Provide practice. B. Supply data to record. C. Replicate the work for validity. D. Provide reliable data for conclusions. 10. Each student in a science class of 25 performed the same experiment. Each student shares their data and it is recoded on a class data table. Tamara compared the data that she personally collected in her experiment to the data collected by the rest of her classmates. Which of the following might indicate to her that her results are valid? A. Three other classes performed the same experiment. B. The same experiment was repeated two years in a row. C. Many other students recorded data similar to hers. D. Another student in her class reached a different conclusion. 11. The chart below shows the density of seawater samples collected from the Gulf of Mexico by four different groups. Which group s data is most reliable? A. Group 1 B. Group 2 C. Group 3 D. Group 4 12. Kim wanted to determine if certain seeds require sunlight in order to germinate. She placed one seed on a moist paper towel in the sunlight. She placed a second seed on an equally moist paper towel in a dark closet. The seed in the sunlight germinated but the seed in the dark closet did not. Kim concluded that this type of seed needs sunlight in order to germinate. Which of the following would best describe an improvement to Kim s experiment that would strengthen her claim? A. Use many seeds to conduct the experiment. B. Start the samples on different days. C. Use different amounts of water. D. Place the seeds in new locations. Page 3 Unit Assessment #1
13. Three students use their bodies to demonstrate how the Earth, moon and sun are aligned during each phase of the moon. What is one limitation of this model? A. It cannot show the relative motion of the three objects. B. It cannot be safely used to show gaseous objects such as the sun. C. It cannot show how the sun s light affects the moon s appearance. D. It cannot be used to show the direction of Earth s revolution. 14. Many scientists believe that global warming has resulted in more active hurricane seasons over the past several years. Meteorologists, who study hurricanes, are able to use data collected by satellites to accurately predict the path of hurricanes. Their predictions may save lives and prevent the destruction of coastal cities. What do these scientific efforts of data collection and research illustrate? A. Technology has eliminated the need for meteorologists. B. Scientists use satellites to control weather conditions. C. The information scientists gather by using advanced technology has increased scientific knowledge. D. Weather satellite technology may make it possible to prevent future hurricanes. 15. Which of the following is most likely to change scientific knowledge? A. more expensive experiments B. more links added to the Internet C. improved methods for conducting opinion polls D. new data or interpretations of the natural world 16. Which of the following is an accurate description of science? A. Hypotheses may or may not be testable. B. Explanations are based on observations, evidence and testing. C. Scientific knowledge does not need peer review and verification before acceptance. D. Understandings will never change with additional data and testing. 17. Rachel Carson was a biologist whose work led to the pesticide DDT being banned by the government in 1972. How did Carson most likely convince the government to ban DDT? A. She wrote books about pesticide use in farming. B. She developed a theory that DDT might harm animals. C. She used data to show that DDT harmed animals. D. She led debates in Congress about pesticide use. Page 4 Unit Assessment #1
18. People once believed that insects could spontaneously appear on rotting meat. Which of the following is the most likely reason that this belief was revised? A. People saw fish appear from mud. B. Microscopes and other tools were invented. C. Many more people observed insects appear on rotten meat. D. New observations and data that did not support that hypothesis were made when an experiment was conducted to test it. 19. Four cars were rolled down three different tracks. The time it took for each car to travel down the track was recorded in the data table below. RACE TIME Car Track 1 Track 2 Track 3 1 2.0 s 2.3 s 4.0 s 2 2.5 s 3.0 s 4.5 s 3 4.0 s 4.6 s 8.0 s 4 1.5 s 2.0 s 3.5 s Based on the data collect, if the cars were rolled down a 4 th track, which car would probably finish first? A. Car 1 B. Car 2 C. Car 3 D. Car 4 20. What is one characteristic of scientific laws? A. Scientific laws are constantly being developed, revised, or discarded. B. Scientific laws describe results that scientists expect every time certain conditions are met. C. Scientific laws were made to be broken. D. Scientific laws explain different results for the same repeated experiment. 21. Unlike a law, a scientific theory is an interpretion of a wide range of observations with a single explanation. Which of the following examples is a scientific theory rather than a law? A. In layers of rock, the oldest layer is the bottom. B. All objects in the universe attract each other. C. All cells come from prexisting cells. D. Mass cannot be created ot destroyed in chemical reactions. 22. Earth s crust is made up of large and small plates that are in slow, constant motion, driven by convection curents in Earth s mantle. Scientists who study Earth have consistently observed that most earthquakes and volcanoes occur where plates meet. Plate tectonics is an example of A. a scientific law. B. a scientific theory. C. a hypothesis. D. a prediction. 23. Which of the following best explains how a scientific theory might be changed? A. All scientists agree to change the theory. B. Several scientists propose a new theory. C. Data from new experiments could lead to revisions of the theory. D. Theories do not change because they are based on well-tested hypotheses. Page 5 Unit Assessment #1