Scientific method variables (worksheet) | PDF - Free Printable

Problem Analysis:

The image provided shows an experiment setup where three potted plants are exposed to different colored lights (red, green, and yellow). The task is to analyze the diagram and answer two questions related to the experimental design.

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Question 1: According to the diagram, which question is being tested?

#### Step-by-Step Reasoning:
1. Observation of the Diagram:
- There are three potted plants, each placed under a different colored light (red, green, and yellow).
- All other factors (e.g., soil type, pot size, plant type) appear to be consistent across the three plants.
- The only variable that differs is the color of the light.

2. Understanding the Variables:
- Independent Variable: The factor being manipulated in the experiment. Here, it is the color of the light.
- Dependent Variable: The factor being measured or observed. In this case, it is likely the growth of the plants (e.g., height).

3. Analyzing the Options:
- Option (a): "Do flowering plants grow taller in red, green, or yellow light?"
This directly aligns with the experimental setup, as the plants are exposed to different colored lights to observe their growth.
- Option (b): "How much fertilizer do flowering plants need?"
There is no mention of fertilizer in the diagram, so this option is irrelevant.
- Option (c): "Does adding fertilizer cause flowering plants to grow taller?"
Again, there is no indication of fertilizer being used in the experiment, so this option is incorrect.
- Option (d): "What is the best kind of soil to make plants grow taller?"
The soil appears to be the same for all plants, so this is not the focus of the experiment.

#### Conclusion for Question 1:
The experiment is testing how different colored lights affect plant growth. Therefore, the correct answer is:

Answer to Question 1:
\[
\boxed{a}
\]

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Question 2: Write "change" beside the change variable; responding beside the responding variable; and control beside any control variables.

#### Step-by-Step Reasoning:
1. Identifying Variables:
- Change Variable (Independent Variable): This is the factor that is intentionally changed or manipulated in the experiment. Here, it is the color of the light.
- Responding Variable (Dependent Variable): This is the factor that is measured or observed in response to the change. Here, it is the growth of the plants (e.g., height).
- Control Variables: These are factors that are kept constant to ensure that any observed changes are due to the independent variable. Examples include:
- The size of the pot.
- The kind of potting soil.
- The type of plant.
- The amount of water given to the plants.

2. Labeling the Variables:
- Change: The factor being manipulated (color of the light).
- Responding: The factor being measured (growth of the plants).
- Control: Factors kept constant (size of the pot, kind of potting soil, etc.).

#### Filling in the Blank:
The blank asks us to label the "kind of potting soil." Since the kind of potting soil is kept constant across all plants, it is a control variable.

#### Conclusion for Question 2:
\[
\text{_________ is the kind of potting soil.}
\]
The correct label is control.

Answer to Question 2:
\[
\boxed{\text{control}}
\]

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Final Answers:

1. \(\boxed{a}\)
2. \(\boxed{\text{control}}\)