IFA 1 Practice 1

Gretchen wants to run a test to discover whether glass, copper, wood, or plastic conduct electricity. She sets up a circuit connecting a battery to a light bulb, with a small gap she will use to test the conductivity of the different substances. One at a time, she connects the circuit with the chosen test material, and records whether or not the light bulb comes on. The independent variables in this experiment are

• The wood and glass.

• The copper and plastic.

• The light bulb and battery.

• The plastic, wood, copper, and glass.

Jane and Jill wondered if plant shoots always grew up toward the light. The two girls planted several pots of seeds. After the seeds germinated, they removed them from the soil and and repositioned the seeds in the ground. They place one-third in the normal position for growth, roots down and shoots up. This was the control group. They placed another third up-side down or shoots down and roots up. They placed the last group on their sides so the shoots and roots were both oriented horizontally. What else should the girls do in order to ensure that their results are valid?

• Fertilize the two experimental groups but not the control group.

• Place one group of seeds outside and keep the other two groups indoors.

• Be sure all other conditions remain constant throughout all three groups.

• Keep the control group in the pot but place the other two groups in the soil.

Alonzo and Meg tested different surfaces to see which one had the least friction. They predicted that the car, seen above, would travel FASTEST down the ramp when the surface covering had the least friction. Alonzo and Meg used carpet, sandpaper, and glass to cover the ramp. They let the car go, not pushing it but letting gravity pull the car to the bottom of the ramp. What were the controlled variables in the experiment?

• how fast the car moved down the ramp

• the different types of ramp coverings

• ramp height, the car, and using gravity

• pushing or not pushing the car down the ramp

Kevin decides to find out which fertilizer is best for tomatoes. He pots up three plants, all with the same soil, giving one no fertilizer, giving the second type A fertilizer, and giving the third type B fertilizer. In this experiment, what is the control or Kevin's standard for comparison?

• The soil used for every plant.

• The plant that got no fertilizer.

• The plant that got type A fertilizer.

• The plant that got type B fertilizer.

Which animal has the most restrictive pH requirement?

• bass

• clams

• crayfish

• frogs

Mr. Kline's earth science class set up an experiment to compare the heating and cooling rates of sand and water. They filled cups with sand and water and then recorded the temperature change while (a) a light was shining directly on the cups and (b) the light was turned off. The data one group collected is presented in the data table. Based on this data, we would expect ___________ to have the greatest changes in temperatures during a 24-hour period.

• cities

• deserts

• the oceans

• mountainous areas

When an experiment is repeated and the new results are different from the original results, what could you assume to be true?

• The results from both experiments are worthless.

• The first experiment's results are worthless and should be discarded.

• The experimental design is flawed and the experiment should be discarded.

• Neither test results are 100% reliable and additional experimentation is needed.

If a new body of evidence were found that directly contradicted the cell theory, groups of scientists would then

• discard the new evidence idea because theories cannot be changed.

• automatically replace the contradiction with this new idea and amend the theory to reflect the new body of evidence.

• create a brand new theory to contradict the old Cell Theory.

• allow for experimentation and analysis of results before making a decision. These experiments should look for a large degree of similarity between what the scientist observed and/or calculated versus what the committees of scientists calculate.

Six students were asked to perform an experiment to see how the mass of a pendulum affected its period. They were given supplies and asked to design an experiment to test the impact that the mass of the bob had on period. What would likely make their results more reliable?

Having an experiment repeated by others is called ? (a)  

• Repetition
• Replication
• Experiment