Scientific Method

Students were investigating some properties of rocks. They wanted to compare the volumes of the rocks.

Which tool should the students use to accurately measure the volume of each rock?

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Some researchers are developing a new fertilizer designed to improve the growth of plants in hot, dry climates. The fertilizer was applied to one hundred desert plants in a greenhouse. The average daytime temperature in the greenhouse was 90°F, and the humidity levels were low. Which is best for the researchers to do next?

• A compare plants that received fertilizer to similar plants that received none

• B begin selling the fertilizer to gardeners living in hot, dry climates

• C change the conditions in the greenhouse and retest the fertilizer

• D test the fertilizer on plants that are adapted to cooler climates

A scientist investigates the effect of carbon dioxide on plant height. The scientist grows plants in several closed containers. All the plants receive the same amounts of water and light, but the air in each container has a different amount of carbon dioxide. What is the independent variable in this experiment?

• the amount of carbon dioxide in each container

• the number of plants in each container

• the amount of water provided to the plants

• the height of each plant after a period of time

A meteorologist recorded high temperatures for five days at three locations on land. The data are shown in the table below.

• Areas at the beach have the coolest temperatures

• Areas farther from the beach always have the warmest temperatures.

• Areas at the beach have the most stable temperatures.

• Areas farther from the beach always have the same weather as areas at the beach

The students concluded that the plants grown indoors grew faster because they received better quality light than the plants grown outdoors. Which is the most likely reason this conclusion may be flawed?

• The students measured the plants at different times.

• The students should have grown different types of plants.

• The growth of the plants in each set was affected by more than one factor.

• The outdoor plants grew faster than the indoor plants.

Some scientists want to design a system of instruments that will evaluate ocean currents, temperatures, and winds in order to predict weather patterns. What should they do before they produce the first complete working version of the system?

• build a prototype of the system

• evaluate the results of the system

• improve the design of the system

• conduct tests on the system

A student filled three identical cups with equal amounts of water. The student placed each cup in a room with a different air temperature. After a few days, the student compared the amounts of water remaining in each cup.

What cause-and-effect relationship does this investigation support?

• As evaporation decreases, air temperature decreases.

• As evaporation increases, air temperature increases.

• At higher air temperatures, more water evaporates.

• At higher air temperatures, less water evaporates.

Students in a science class plan to investigate a factor that affects the rate at which a pendulum swings.

In which way should the students manipulate the variables to get valid results in this investigation?

• use equal string lengths and different plumb bob masses

• use different string lengths and different plumb bob masses

• use equal string lengths and the same plumb bob shapes

• use different string lengths and different plumb bob shapes

A student hypothesized that a mouse would learn to run through a maze faster if food was at the end of the maze.

Which tool will best help the student determine if the speed of the mouse improved?

• metric ruler

• pan balance

• stop watch

• spring scale

The table shoes different types of pollination data for the fruit from one plant species.

Which graph best represents some of the data in the table?

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