Unit Test Answers

Scientists must be able to repeat an experiment and get very similar results; otherwise their conclusions will be questioned. If the results of a repeated experiment are different from the original results, the results of the experiment

Two scientists write a paper detailing their research and conclusions and submit it to a scientific journal. Several months later, the publisher sends them back the paper. Many comments from several fellow scientists are attached. Which step will the authors of the paper most likely take next?

Ideas about the components of cells have been affected by new technologies. Four technologies are listed below. Which one enabled researchers to understand the basis of the other three?

Rachel is performing an acid-base titration. She hopes to determine the concentration of an unknown acid solution to two decimal places. Which is the best tool to find the volume of the base that she needs to neutralize the acid?

There is little sunlight at high latitudes during the winter, so few crops can grow even if temperatures are regulated. To address this problem, special lamps can be used in greenhouses. These lamps allow plants to grow during the winter months. Scientific knowledge of which topic was necessary to solve this problem?

A scientist investigated the effects of morning temperatures on flower width. Which most likely could have been a source of error in his investigation?

A hypothesis must be

Many kinds of data can be gathered in the study of ocean water. Predictions are based on accurate and precise scientific data. Which of these sets of data will yield the most precise data?

The graph below shows changes in Earth’s average surface temperature since 1880.The general trend that is shown on the graph is that average surface temperature on Earth

A scientist designed and conducted an experiment to test a hypothesis, and then formed a conclusion from her results. Next, she collected and analyzed more data and formed another conclusion. Which statement best justifies the fact that she skipped the hypothesis and experimental design steps of the scientific method?

Yusef adds all of the values in his data set and then divides by the number of values in the set.What is Yusef most likely finding?

Why do new scientific discoveries or technological developments often lead to new career opportunities?

Which most likely is a causal relationship?

Read the passage about bird food and bird watching. Noted scientist Dr. Elsa Birde described the effect of adding a mixture of dried apples and raisins to the previous feed of sunflower seeds, millet, thistle seed, and cracked corn in bird feeders in her yard. Over three years, Dr. Birde observed that the new mixture increased the number of songbirds at her feeders, especially during the months of April and May. As she has done for several years, Dr. Birde recorded, at the same time each day, the number of birds at each of her four feeders. She noted that the third year using the mixture coincided with the largest increase. There was a twenty-five percent increase in the number of songbirds over times when this mixture was not used. Dr. Birde also noted that in the third year she used a specific ratio of the ingredients, carefully measuring, which she had not done in previous years. The third year also had a warmer than normal spring, and a construction project began in a neighborhood near Dr. Birde’s. Dr. Birde is now going to produce this formula for sale and advertise to customers that they may see the same twenty-five percent increase in songbirds at their feeders.Dr. E. Birde, Journal of Scientific Bird FeedingWhich scientific claim can be made?

The accepted value for the density of liquid mercury is 13.5336 g/mL. Four scientists measure the density of liquid mercury in their individual laboratories. The most accurate measurement is made by