Question

name:____________________ period:______ date:________

1. scenario: a company wants to determine if their new cough syrup works. they give one group of people with coughs the new syrup and another group a placebo (a sugar - water solution). they then survey both groups to see if their coughs improved.

manipulated variable
responding variable
controlled variables

1. scenario: a student investigates whether the type of soil affects how fast an earthworm can burrow. she places three earthworms in three different types of soil (sand, clay, and loam) and records the time it takes for each worm to burrow to a depth of 5 cm.

manipulated variable
responding variable
controlled variables

1. scenario: does the color of light affect the rate of photosynthesis in a plant? a biologist places identical plants under different colored lights (red, blue, green) and measures the amount of oxygen produced by each plant.

manipulated variable
responding variable
controlled variables

Explanation:

5.

Step1: Identify manipulated variable

The variable the company changes is the type of substance given (new cough - syrup or placebo).
Manipulated Variable: Type of substance (new cough - syrup or placebo)

Step2: Identify responding variable

The variable that changes in response to the manipulated variable is whether the cough improved.
Responding Variable: Whether the cough improved

Step3: Identify controlled variables

Controlled variables are factors that are kept the same for both groups. These include the initial severity of coughs, age - range of participants, time of survey, etc.
Controlled Variables: Initial severity of coughs, age - range of participants, time of survey

6.

Step1: Identify manipulated variable

The student changes the type of soil.
Manipulated Variable: Type of soil (sand, clay, loam)

Step2: Identify responding variable

The variable that responds to the type of soil is the time it takes for the earthworm to burrow.
Responding Variable: Time for earthworm to burrow to 5 cm depth

Step3: Identify controlled variables

Controlled variables include the size of earthworms, the depth of 5 cm (constant), temperature of the environment, etc.
Controlled Variables: Size of earthworms, depth of 5 cm, temperature of environment

7.

Step1: Identify manipulated variable

The biologist changes the color of light.
Manipulated Variable: Color of light (red, blue, green)

Step2: Identify responding variable

The variable that responds to the color of light is the amount of oxygen produced by the plant.
Responding Variable: Amount of oxygen produced by the plant

Step3: Identify controlled variables

Controlled variables include the type of plant (identical plants), the intensity of light, the duration of light exposure, etc.
Controlled Variables: Type of plant, intensity of light, duration of light exposure

Answer:

Step1: Identify manipulated variable

The biologist changes the color of light.
Manipulated Variable: Color of light (red, blue, green)

Step2: Identify responding variable

The variable that responds to the color of light is the amount of oxygen produced by the plant.
Responding Variable: Amount of oxygen produced by the plant

Step3: Identify controlled variables

Controlled variables include the type of plant (identical plants), the intensity of light, the duration of light exposure, etc.
Controlled Variables: Type of plant, intensity of light, duration of light exposure