Designing Scientific Investigations Answers

Tim makes a volcano demonstration for a class. He crafts the volcano out of clay, and then pours vinegar into the baking soda that is inside the volcano. What would be the best way for Tim to turn this demonstration into an experiment?

Which statement describes the dependent variable?

Choose the best experimental design to test the question “Does the gender of mice affect the time it takes to learn mazes?”

Carlo is wondering what causes plants to grow at different rates. Carlo’s hypothesis is “Plants will grow more when the day is longer.” To test his hypothesis, Carlo sets up an investigation that includes an experimental and control group. What factor would remain constant in the control group, but would change in the experimental group?

A zoology student is investigating whether it is true that the gender of turtles depends on the temperature at which the turtle eggs are kept before they hatch. He will test if turtle eggs incubated at 29–30 degrees Celsius produce females, and eggs at 24–26 degrees Celsius produce males. What is the independent variable?

A scientist monitors the number of eggs in five duck nests in parks, five duck nests in zoos, and five duck nests in the wild during the spring and summer for three years. He makes a multiple line graph to plot and compare data for the three locations. Which question describes what the scientist is most likely testing?

Repeating tests usually leads to

Mei wants to study whether heart rate increases more during certain exercises than during others. She designs an experiment to test the heart rates of classmates in the morning and in the evening for three days, immediately after doing jumping jacks, doing push-ups, or running in place. What is the dependent variable in this experiment?

The photograph below shows Jamal’s bird feeder. Jamal asked the question “Are hummingbirds attracted more to red feeders than to feeders of other colors?”What is the independent variable in Jamal’s experiment?

What is another term for the responding variable?

A student wants to answer the question “Does adding calcium powder to soil make pea plants grow faster?” She adds calcium powder to the soil of 12 plants and does not add it to the soil of a second group of 12 plants. She measures the growth of all of the plants in each group for a month. Which statement best summarizes the factors that need to be controlled in this experiment?

During an investigation, Sam observes the number of hummingbirds that come to his large bird feeder at different times of day. He fills the feeder to the top the first day and counts the number of birds at 6 a.m., noon, and 6 p.m. over ten days. What are the independent and dependent variables in Sam’s investigation?

Max wants to see if mice that are fed food A grow faster than mice that are fed food B. He measures the mass of the mice each day. He feeds each group the same amount of food at the same time each day. What is the dependent variable?

Megan wants to see if mice that are fed food A or B grow at a faster rate. She measures the mass of the mice on day 1, then divides them into two groups based on the type of food they will be given. She feeds each group the same amount of food at the same time each day. Does Megan have a control group in this experiment?