PISA - Program for International Student Assessment Scientific Literacy and Enquiry Questions and Answers

Question 1

A student conducts an experiment to test the hypothesis that caffeine increases the heart rate of daphnia (water fleas).
She places a daphnia on a microscope slide in a drop of water and measures its heart rate.
She then adds a drop of caffeine solution and measures the heart rate again.
To ensure the reliability of her results, which of the following is the most important next step?

Accepted Answer

Repeating the experiment multiple times with different daphnia.

Answer

Testing a different type of organism to see if it reacts the same way.

Answer

Using a stronger concentration of caffeine to get a more obvious result.

Answer

Publishing her single result immediately to claim the discovery.

Question 2

On a humid day, small droplets of water form on the outside of a glass of ice-cold water. Which of the following statements best explains this phenomenon scientifically?

Accepted Answer

Water vapor from the surrounding air cools and condenses into liquid on the cold surface.

Answer

The cold temperature causes the glass to sweat out water from within its structure.

Answer

The ice inside the glass is melting and seeping through microscopic pores.

Answer

Oxygen and hydrogen atoms from the air spontaneously combine to form water on the glass.

Question 3

A team of researchers wants to investigate the effects of a new running shoe on athletic performance. Which of the following questions is a scientific question that can be investigated through their experiment?

Accepted Answer

Does running in the new shoes affect a runner's 100-meter sprint time?

Answer

Do the new running shoes look better than the old ones?

Answer

Is the price of the new running shoes fair for the technology they use?

Answer

Does wearing the new shoes make runners feel happier?

Question 4

A student reads a blog post that claims, 'Using a smartphone for more than two hours a day is guaranteed to cause brain damage.' As a scientifically literate citizen, what should be the student's most critical first step?

Accepted Answer

Look for the evidence and the source of the claim to evaluate its credibility.

Answer

Immediately stop using their smartphone for more than two hours.

Answer

Accept the claim as true because it sounds serious and scientific.

Answer

Share the blog post with friends to warn them of the danger.

Question 5

In a well-designed scientific experiment, what is the purpose of a 'control group'?

Accepted Answer

To provide a baseline for comparison with the experimental group.

Answer

To have a group that can be stopped if the experiment goes wrong.

Answer

To test multiple variables at the same time on one group.

Answer

To ensure the researchers have control over the weather.

Question 6

A graph in a health report shows that as ice cream sales increase, the number of drowning incidents also increases. The report concludes that eating ice cream causes drowning. Why is this conclusion likely flawed?

Accepted Answer

The conclusion ignores a likely third variable, such as warm weather, that causes both to increase.

Answer

The graph is probably inaccurate because ice cream is a solid and can't cause drowning.

Answer

The conclusion is valid because the data shows a clear positive correlation.

Answer

The study should have been conducted in winter to get more accurate results.