Nature of Science Benchmarks (NGSSS 7th Grade)

Steps in a scientific investigation vary, but must follow a logical sequence. Which list shows the best sequence for steps in a scientific investigation?

• analyze data, defend conclusions, define a problem, form a hypothesis
• analyze data, form a hypothesis, define a problem, defend conclusions
• define a problem, form a hypothesis, analyze data, defend conclusions
• form a hypothesis, define a problem, defend conclusions, analyze data

Experiments have both test variables (independent variables) and outcome variables (dependent variables). Which describes a test variable (independent variable)?

• A scientist carefully notes all of the conditions in the environment while observing bald eagles.
• A scientist investigating frog behavior alters the temperature in a frog’s environment.
• A scientist observes that plants that receive red and blue light grow faster than those that receive yellow light.
• A scientist performing an experiment on plant growth makes sure that temperature and soil conditions are the same for all plants.

Tags

NGSS.MS-PS2-2

Which choice best describes a testable hypothesis?

• Carrots look better when given more water.
• Lilacs are better smelling than roses.
• Mountain lions travel over 100 km per day.
• The bacterium E. coli is worse than the bacterium S. aureus.

Tags

NGSS.MS-LS1-5

A scientist raises the temperature of a sample of water to find out if the amount of salt that can be mixed into the water changes. Which is the outcome variable (dependent variable)?

• the temperature of the water
• the amount of water in the sample
• the type of salt mixed into the water
• the amount of salt that mixes in the water

Scientists investigate questions in different ways. Which best describes an experiment?

• A biologist watches a single herd of elephants over several months.
• A climate scientist put data into computer programs to make predictions.
• An astronomer uses specialized tools to gather data about distant galaxies.
• A physicist puts an object into a vacuum chamber and measures how fast it falls.

Tags

NGSS.MS-PS2-2

Which choice does not describe replication?

• Two astronomers observe an eclipse from different observatories.
• Two scientists both perform experiments on the same species of plant.
• A scientist reads a journal article, and then does the experiment it described.
• A scientist shares a procedure with another scientist who then does the experiment.

A scientist describes an experiment as follows: Two identical plants were grown in identical conditions, except one received fertilizer and water while the other received only water. The plant that received fertilizer grew faster. Which best describes why the experiment either can or cannot be replicated?

• The experiment can be replicated because the results were indicated.
• The experiment can be replicated because both plants had identical conditions.
• The experiment cannot be replicated because no two plants are exactly the same.
• The experiment cannot be replicated because the methods are not fully explained.

Repetition and replication are important methods for validating scientific results. Which best describes why?

• Repeating and replicating investigations can show if scientists make errors
• Repeating and replicating investigations gives more scientists a chance to work.
• Repeating and replicating investigations takes time and effort, but are necessary.
• Repeating and replicating investigations allows the public to decide if the results are valid.

Which describes repetition?

• A chemist measures the timing of a chemical reaction several times.
• A large-scale experiment is conducted by a team of several scientists.
• One scientist tells another scientist about the results of an experiment.
• A scientist looks at data from an experiment and interprets it in a new way.

Which is not an example of repetition?

• Susan makes a baked pasta recipe for the second time.
• Frank conducts an experiment already done by Rico on soil bacteria.
• Bryan tests his physics experiment again in the same day.