Unit 1 Test review

Students are studying the effects of beach pollution by counting populations of seagulls at two different beach locations. One location is a beach near a large industrial marina where boats are serviced; the second location is an isolated beach surrounded by a state park. The students plan to count all the visible seagulls at the beaches at specific times of day. They will repeat the bird count for 10 days and then analyze the data.

What is the outcome variable (dependent variable) in this study?

• the size of the beach

• the number of seagulls at each location

• the temperature of the water at the beach

• the number of days the seagulls were counted

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Ricardo wanted to conduct an investigation to determine what color light is best for plant growth. He predicted that orange light will cause tomato plants to grow the tallest. He developed the following steps to conduct his investigation:

Five identical tomato plants were placed in the same type of container with equal amounts of soil and water

. He shined one color of light on each of the five tomato plants for the same amount of time each day, using the colors red, orange, blue, green and purple.

The height of each plant was measured and recorded at the beginning of the experiment and daily for 30 days.

What essential part of his investigation is missing?

• a question

• a hypothesis

• a control group

• an outcome variable (dependent variable)

Tags

NGSS.MS-ETS1-1

The graph below shows the average growth rate for 38 pairs of newborn rats. One of each pair was treated with a special hormone. The other member of each pair served as a control.

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At 125 days, what was the average weight of the rats in the experimental group?

• 48 grams

• 50 grams

• 235 grams

• 325 grams

Tags

NGSS.MS-LS1-5

An experiment was set up to test the hypothesis that all plants will grow faster in a "super soil" versus regular potting soil. Six identical plants were tested, three in the "super soil" and three in regular potting soil. All plants received the same amount of water, light and fertilizer. Which of the following items would improve the experiment?

• add more types of plants

• test one plant with no fertilizer

• use different soils for each plant

• expose all six plants to green light

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-4

Francine rolled a marble down a ramp and timed how long it took for the marble to reach the bottom of the ramp. After one trial, she doubled the height of the ramp and added a thick layer of wool cloth to the surface of the ramp. She conducted three more trials and after reviewing the data, Francine concluded that the height of the ramp had no effect on the speed of the marble rolling down the slope.

Which of the following reasons best describes why her conclusion is unsupported?

• Francine miscalculated the speed of the marble.

• More trials were needed during the investigation.

• A control should have been used in the investigation.

• Too many variables were changed during the investigation.

Tags

NGSS.MS-PS2-2

A class of seventh grade students conducted various scientific investigations throughout the year. The following table lists statements from the procedures of the investigations.

STATEMENTS FROM PROCEDURES OF DIFFERENT INVESTIGATIONS

Which statement is the best example of repetition?

• Investigation 1

• Investigation 2

• Investigation 3

• Investigation 4

An engineer is researching the effects of a new safety device for automobiles. She plans to conduct a controlled scientific experiment where she will test a safety device’s effect on being able to survive a head-on collision.

Why is it important to replicate the engineer's experiments?

• to compare the experimental results with current safety devices available in most cars

• to allow other engineers to conduct the same experiment and confirm experimental results

• to provide engineers with results from a control group with which to compare the experimental results

• to manipulate only one safety device at a time to provide the researchers with more reliable experimental data

Tags

NGSS.MS-PS2-5

Neil is comparing the shifts in light patterns of two distant galaxies. Using a powerful telescope, he records the light shifts of each galaxy every 20 seconds (s) for six hours (hr). After sharing his data with Betty, another astronomer, she says that this is not an experiment.

Which of the following statements supports Betty's claim?

• This is not an experiment because there are too many variables.

• This is not an experiment because no variables are manipulated.

• This is not an experiment because it uses only theoretical predictions.

• This is not an experiment because astronomers are not considered research scientists.

Tags

NGSS.MS-ETS1-1

Which of the following statements best describes why developing a hypothesis is an important step in a scientific investigation?

• The hypothesis is actually the first step in the scientific method.

• The hypothesis guides the researcher towards the results of the experiment.

• The hypothesis provides the steps needed to analyze the data to reach conclusions.

• The hypothesis provides a prediction about what might happen during the experiment.

Fiona wanted to determine if sugar water affected the growth rate of bean plant seeds. She buried a total of 12 bean plant seeds, each in its own pot with identical soil and placed the pots in a sunny place. She watered each group of plants with 200 milliliters (mL) of water mixed with a specific amount of sugar. The table below shows the final height in centimeters (cm) of the plants after the experiment was completed.

EFFECT OF SUGAR WATER ON THE GROWTH OF BEAN PLANTS

Did the experiment correctly use the scientific method for experimentation?

• No, because the amount of sugar was not high enough to make a difference in the growth.

• No, because there was no control setup in the experiment, so a comparison cannot be made.

• Yes, because there were multiple trials and several test variables (independent variables) that were tested.

• Yes, because there were multiple trials and all the plants had some sort of growth so all requirements were met.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1