Nature of Science Review

Shawn conducted an experiment and did not get the results he was expecting. What should he do first?

• Shawn should write conclusions.

• Shawn should share his results.

• Shawn should explain what he thought should have happened.

• Shawn should check his experiment for errors and try again.

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Identical investigations should produce similar results if conducted accurately. Sometimes, uncontrolled variables can cause differences in results.

Sandra and Jeremy are neighbors who tested different brands of seeds in their gardens for six weeks. They grew identical gardens in their yards and recorded results. Each of them tried three brands of pea plant seeds and recorded the plants' heights at the end of each week. They discovered Jeremy's plants were much taller on average than Sandra's plants every week.

Which statement describes an uncontrolled variable that may have caused such a significant difference in their results?

• Sandra discovered several rabbits had been munching on her pea plants, while Jeremy had none.

• 
  Sandra weighed each brand of seeds before planting them, while Jeremy did not weigh his seeds.

• Sandra and Jeremy both used the same type of soil and provided the same amount of water each day.

• Sandra recorded her measurements in centimeters, while Jeremy recorded his plant heights in inches.

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If conducted accurately, identical investigations should produce similar results. Sometimes, errors, like measurement errors, can cause differences in results.

Sandra and Jeremy are neighbors who tested different brands of seeds in their gardens for six weeks. They grew identical gardens in their yards and recorded results. Each of them tried three brands of pea plant seeds and recorded the plants' heights at the end of each week. They discovered Jeremy's plants were much taller on average than Sandra's plants every week.

Which statement describes a measurement error that may have caused such a significant difference in their results?

• Sandra recorded her measurements in centimeters, while Jeremy recorded his measurements in inches.

• They both took measurements on Fridays, but Sandra took hers at 4:00 PM, and Jeremy took his at 5:00 PM.

• 
  Sandra used a measuring tape to collect data, while Jeremy used a wooden ruler to take his measurements.

• 
  Sandra measured her plants from the ground, while Jeremy measured his plants from the ends of their roots.

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When scientific investigations are repeated by other scientists, they usually produce the same results. When results are significantly different from one another, scientists investigate what may have caused the differences. Which of these factors would cause the most difference in results of repeated investigations?

• equipment failures

• 
  exact measurements

• incorrect hypotheses

• 
  controlled variables

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Kierra is trying to decide which brand of lettuce seeds she would like to use in her garden this summer. After researching, she picked the two best-known brands to test. She decides to test them by planting one of each seed in a small space in her yard; her observations will be recorded so she can compare.

What is the best reason why Kierra should consider planting more than one seed from each brand?

• She has enough room in her yard to grow more.

• 
  Growing lettuce does not require much maintenance.

• She will have more data from each brand to compare.

• 
  The soil and sunlight in her yard may not be best for lettuce.

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Kierra is trying to decide which brand of lettuce seeds she would like to use in her garden this summer. After researching, she picked the two best-known brands to test. She decides to test them by planting one of each seed in a small space in her yard; her observations will be recorded so she can compare.

What is something Kierra can do to get more accurate data on her lettuce plants?

• 
  She should test at least five brands.

• She should plant several seeds from each brand.

• She should not record her observations until the end of her test.

• She should mix the seeds together and plant them in the same hole.

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Scientists use various types of models to represent real world activity. For instance, computer models are used to predict weather patterns, and the physical models of Thomson and Rutherford have been used to help us understand the structure of the atom.

Scientific models like this are useful because they can help to describe and predict natural behavior. However, such models are limited, and...

• they in no way reflect the natural world

• their predictions are almost never accurate

• their predictions are not accurate every single time

• they can only be used by experienced scientists to make relevant predictions

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Cell phones have gotten much smaller in the past 15-20 years. Although the design of the phones themselves has changed a lot, the MAIN reason engineers have been able to make them smaller is that

• the emergence of touchscreens has made keypads unnecessary.

• better reception and transmission has made antennas unnecessary.

• 
  people spend less time on the phone now, so the phones can be less powerful.

• technological advances have made it possible to make smaller, more powerful batteries.

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Sandy is building a small toy car. He wants to use a balloon to power the toy car. He fills a balloon with air and then attaches a straw to the balloon. He tapes the balloon-straw combination to the car and then releases the end of the balloon.

The toy moves forward as the air from the balloon comes out the back of the straw. What can Sandy do to make the toy car move faster?

• Use less air in the balloon.

• 
  Blow up the balloon more.

• Use a longer straw.

• Use larger tires.

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Your science class decides to study the phases of the moon. To do this, you would like a magnified, close-up view of the moon.

What scientific instrument could you use for this?

• 
• 
• 
• 

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