Nature of Science

The following bar graph shows the population of bacteria under different temperature ranges.  What can be concluded about the bacteria from reading this graph?

• They thrive at exactly 30°C.

• They cannot tolerate temperatures above 50°C.

• They prefer temperatures between 20°C and 30°C.

• They prefer warmer temperatures to cooler temperatures.

Tags

NGSS.MS-LS1-5

Consider the following hypothesis, “Drinking too many soft drinks causes calcium deficiency in teens.” A scientist plans an experiment to test the hypothesis. What is the outcome variable (dependent variable)?

• the type of soft drink consumed

• the amount of soft drinks the teens drink

• the number of teens in the test

• the level of calcium in the teens

Helen is studying the growth of two different types of plants. She planted two of each type of plant in locations with different levels of sunlight: full sun, partial shade, and full shade. For five weeks, Helen records the number of new leaves on each plant. Which of the following statements correctly describes the independent and dependent variables in Helen's experiment?

• The independent variable is the amount of sunlight, and the dependent

  variable is the number of new leaves

• The independent variable is the kind of plant, and the dependent

  variable is the amount of sunlight.

• The independent variable is the amount of sunlight, and the dependent

  variable is the kind of plant.

• The independent variable is the number of new leaves, and the

  dependent variable is the amount of sunlight.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Gabriella is testing wing shapes for model airplanes to find the fastest airplane design. She records the flight time over 100 meters for models with different wing shapes. Gabriella records the flight times for each shape three times and then finds the mathematical average. Which statement best describes one of the steps that Gabriella is doing?

• She is replicating her experiment to decrease the reliability of the results.

• She is replicating her experiment to increase the reliability of the results.

• She is performing repeated trials of the experiment to decrease the reliability of the results.

• She is performing repeated trials of the experiment to increase the reliability of the results.

Tags

NGSS.MS-ETS1-3

Which of these experimental procedures is most likely to produce reliable data?

• Detergents are tested against warm water for their ability to remove bacon grease from a pan. One trial is performed for each brand of detergent.

• A metal coil is tested for elasticity by measuring both its stretch distance and its recoil with a 5kg weight. The results are verified by replication by another scientist.

• A material is tested for friction by recording the time it takes a ball of the material to roll one meter down an inclined plane. The time measurements are averaged over three trials.

• A fertilizer is tested for its ability to increase height of tomato plants. Plant height of several treatment groups are averaged over three trials. The experiment is sent to two other labs for replication.

Tags

NGSS.HS-PS2-5

A candy company has created a new chocolate bar called a GizmoBar and has conducted a field test to gather public opinion. One hundred people in each of the age brackets shown below, taste tested the GizmoBar and a competitor's product, the Whizobops Bar. They then told which product they preferred. The results are shown below. Which conclusion is best supported by these results?

• GizmoBars were preferred by those between 10 and 35 years old.

• GizmoBars and Whizobops Bars were liked equally well by all

  age groups.

• GizmoBars were preferred by those between the ages of 36 and 50

  years old.

• Those over 50 years of age liked the GizmoBar better than the

  Whizobops Bar.

Samuel conducts an experiment. He makes many observations and measurements and records each very carefully. At the conclusion of the experiment he discovers that the data he collected does not support his hypothesis. What should he do?

• Report his observations and conclusions honestly, clearly

  stating that the data do not support the hypothesis.

• Change his hypothesis to one that is supported by the data.

• Change the data so that they support his hypothesis.

• Throw all of his data and observations away and repeat the

  experiment.

What should a scientist do if a hypothesis is NOT supported by data?

• Carry out further investigations.

• Stop investigating the question.

• Change the hypothesis to match the data.

• Change the data to support the hypothesis.

Tags

NGSS.MS-LS1-5

Which of the following statements about hypotheses is true?

• Hypotheses can never be changed.

• Hypotheses are always proven to be true.

• Hypotheses can be accepted or rejected.

• Hypotheses can be proven true without evidence.

Tags

NGSS.HS-PS1-2

In 2017, an experiment was begun involving two astronauts. Scott Kelley and Mark Kelley are identical twins who both worked at NASA. They both trained to be astronauts at the same time, but in 2017 they separated for an experiment. The results of the experiment are shown below. For the purposes of this study, why was it important that identical twins be involved?

• Identical twins both have the exact same age.

•  Identical twins both had the same development and education during their life.

•  Identical twins both have similar physical characteristics for scientists to test.

• Identical twins both had the same nutrition as children.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS3-1