DLM Science Literacy 2 — Questions and Answers
Question 1: A student observes that plants near a window grow toward the light. What is the best next step to turn this observation into a scientific investigation?
- Tell a friend about the observation
- Form a testable hypothesis and design an experiment (Correct answer)
- Draw a picture of the plants
- Water the plants more frequently
Correct answer: Form a testable hypothesis and design an experiment
A scientific investigation requires forming a testable hypothesis and designing a controlled experiment to test it.
Question 2: Which of the following best describes the role of a control group in an experiment?
- The group that receives the experimental treatment
- The group used to measure the experimenter's skill
- The group that remains unchanged to provide a baseline comparison (Correct answer)
- The group with the most participants
Correct answer: The group that remains unchanged to provide a baseline comparison
A control group does not receive the experimental treatment and serves as a baseline to compare results against the experimental group.
Question 3: A scientist reports that a new fertilizer increases crop yield by 40%. What additional information is most important to evaluate this claim?
- The color of the fertilizer packaging
- Whether the study was peer-reviewed and replicated (Correct answer)
- The scientist's country of origin
- How long the scientist has been working
Correct answer: Whether the study was peer-reviewed and replicated
Peer review and replication are essential to validate scientific claims and rule out bias or error.
Question 4: What does it mean when scientists say a result is 'statistically significant'?
- The result is very large in size
- The result is unlikely to have occurred by chance (Correct answer)
- The result was found by an important scientist
- The result has been published in a textbook
Correct answer: The result is unlikely to have occurred by chance
Statistical significance means the result is unlikely to be due to random chance, suggesting the experimental variable had a real effect.
Question 5: A student measures the length of a worm five times and gets: 8 cm, 8.1 cm, 7.9 cm, 8 cm, 8.2 cm. These measurements are best described as:
- Accurate but not precise
- Precise but not accurate
- Both precise and accurate (Correct answer)
- Neither precise nor accurate
Correct answer: Both precise and accurate
The measurements are clustered closely together (precise) and centered near 8 cm, which is a reasonable true value (accurate).
Question 6: Which type of graph is most appropriate for showing how temperature changes over a 24-hour period?
- Bar graph
- Pie chart
- Line graph (Correct answer)
- Scatter plot with no line
Correct answer: Line graph
A line graph is best for showing continuous change over time, making it ideal for displaying temperature trends across 24 hours.
Question 7: In science, a theory is best defined as:
- A guess that has not been tested
- An explanation supported by extensive evidence and repeated testing (Correct answer)
- A single successful experiment result
- A law that has been disproven
Correct answer: An explanation supported by extensive evidence and repeated testing
A scientific theory is a well-substantiated explanation supported by a large body of evidence from many observations and experiments.
DLM Science Literacy 2
A student observes that plants near a window grow toward the light.
What is the best next step to turn this observation into a scientific investigation?