Science Chapter 1 Practice

Leann and Juan are each planning an investigation of the water cycle. Leann plans a descriptive investigation, while Juan plans an experimental investigation. Which step could be part of both investigations?

• A) Forming a hypothesis, such as “The Sun provides the energy for the water cycle.”

• B) Identifying variables for a fair test, such as the saltiness of the water or the air temperature.

• C) Asking people for their opinions about the water cycle and its importance.

• D) Making observations of water and its changes, either in nature or a laboratory.

Three science students are working together on a science investigation of the weather. Here are their journal entries for today’s weather: Melissa: My friends are disappointed because they want to go swimming today. They were hoping for warmer weather. Andrea: The temperature is 75°F, and the sky is clear and sunny. Druhan: Today’s weather is great for playing sports outdoors. I’m glad because I play baseball. Which entry is most useful for the investigation?

• Melissa’s entry, because it compares the weather with a hope or expectation

• Andrea’s entry, because it includes observations and measurements

• Druhan’s entry, because it describes feelings or emotions

• Druhan’s entry, because it explains why the weather is important

Shira is investigating how animals lived in Earth’s distant past. In her report, she claims that giraffes once lived on the plains of North America. How could Shira best support this claim?

• Shira could draw a picture of giraffes finding food on plains.

• Shira could name the friends and classmates who agree with her claim.

• Shira could explain how giraffes might have traveled between North America and Africa.

• Shira could identify fossils of giraffes, such as their bones or teeth, that were discovered in North America.

In the 1980s, two Australian doctors were investigating stomach ulcers. After several experiments, they concluded that ulcers were caused by a strain of bacteria. This conclusion surprised other doctors around the world. Which provided the strongest evidence in support of the conclusion?

• The doctors published advertisements that announced the conclusion in science journals.

• Other doctors repeated the experiments, and the results were the same.

• Doctors studied a model of the stomach and how bacteria formed ulcers.

• Doctors discovered that bacteria cause other diseases and damage to the body.

Why was it useful for the team to conduct four trials of the same step?

• A) They can show that the true falling time is the average of the data, or 2.7 seconds.

• B) They can identify data that likely came from a measurement error or other mistake.

• C) They can discover a way to make objects fall faster or slower.

• D) They can conclude that falling time always changes from one trial to the next.

The science teacher tells Tyler that he needs to include a control group in his experiment. Tyler can study a control group by repeating his procedure, but with one change. Which change should he include?

• In Step 1, do not add food scraps to the soil.

• Skip Step 3, so the soil remains dry.

• Skip Step 4, so there is no paper plate.

• In Step 4, use a sheet of paper that completely covers the soil.

Tyler’s friends say that they also have observed earthworms after rainstorms. How is Tyler’s experiment more useful than the observations of his friends?

• The experiment allowed a hypothesis to be tested in a controlled experiment.

• The experiment tested a small number of earthworms.

• The experiment studied earthworms in a terrarium, not outdoors.

• The experiment studied soil that could be soaked in water.

Which is the most useful conclusion of the experiment?

• Earthworms need the water that may fill spaces in the soil.

• Earthworms need the air that typically fills spaces in the soil.

• Earthworms eat bits of food that they find in the soil.

• Earthworms can move through dry soil, but not wet soil.