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), so the manipulated variable is the type of substance given to the people with coughs.

Step2: Identify responding variable

The variable that changes in response to the manipulated variable is whether the coughs improved or not. So the responding variable is the improvement of coughs.

Step3: Identify controlled variables

Controlled variables are factors that are kept the same. These include the initial condition of the people (all have coughs), the time of the survey, etc.

Step1: Identify manipulated variable

The student changes the type of soil (sand, clay, loam), so the manipulated variable is the type of soil.

Step2: Identify responding variable

The variable that changes in response to the type of soil is the time it takes for the earthworm to burrow to a depth of 5 cm. So the responding variable is the time for earthworm to burrow to 5 cm.

Step3: Identify controlled variables

Controlled variables include the initial condition of the earthworms (similar size, health), the depth of 5 cm, etc.

Step1: Identify manipulated variable

The biologist changes the color of light (red, blue, green), so the manipulated variable is the color of light.

Step2: Identify responding variable

The variable that changes in response to the color of light is the amount of oxygen produced by each plant. So the responding variable is the amount of oxygen produced by the plant.

Step3: Identify controlled variables

Controlled variables include the type of plant (identical plants), the duration of light - exposure, etc.

Answer:

Manipulated Variable: Type of substance given (new cough - syrup or placebo)
Responding Variable: Improvement of coughs
Controlled Variables: Initial condition of people (all have coughs), time of survey, etc.

6.