Question

directions: for the following experiments, identify the independent variable, dependent variable, the manipulated variable, the responding variable and the control variable.

1. different rose bushes are grown in a greenhouse for two months. the number of flowers on each bush is counted at the end of the experiment.

a. independent variable:

b. dependent variable:

c. control variable:

1. three sunflower plants are watered with salt water. each plant receives a different concentration of salt solutions. a fourth plant receives pure water. after a two - week period, the height is measured.

a. independent variable:

b. dependent variable:

c. control variable:

1. three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. one tree is left outside in normal conditions. height of the trees is measured once a week.

a. independent variable:

b. dependent variable:

c. control variable:

1. four plant boxes are given different amounts of water for a three - week period. the first box receives 400 milliliters a day. the second box receives 200 milliliters a day. the third box receives 100 milliliters a day. the fourth box does not receive any extra water. the plants only receive natural rainfall. the height of each plant is measured daily.

a. independent variable:

b. dependent variable:

c. control variable:

Explanation:

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• a. Independent Variable: The independent variable is the factor that is manipulated. Here, the different types of fertilizers (and no fertilizer) are the manipulated conditions, so the independent variable is the type of fertilizer (or the application of fertilizer, including no fertilizer as a control).
• b. Dependent Variable: The dependent variable is what is measured in response to the independent variable. The number of flowers on each bush depends on the fertilizer used, so the dependent variable is the number of flowers.
• c. Control Variable: Control variables are factors kept constant. To ensure a fair test, factors like the type of bush, amount of sunlight, water, soil type, etc., should be kept the same for all bushes. So a control variable could be the type of bush (or amount of sunlight, water, soil type, etc.).

• a. Independent Variable: The independent variable is the factor being manipulated. Here, the concentration of salt in the water (including pure water as a control) is the manipulated condition, so the independent variable is the concentration of salt in the water.
• b. Dependent Variable: The dependent variable is what is measured. The weight of the sunflower plants after a two - week period depends on the salt concentration, so the dependent variable is the weight of the sunflower plants.
• c. Control Variable: Control variables are factors kept constant. Factors like the type of sunflower plant, amount of sunlight, initial size of the plants, etc., should be kept the same. So a control variable could be the type of sunflower plant (or amount of sunlight, initial size of plants, etc.).

• a. Independent Variable: The independent variable is the factor being manipulated. Here, the humidity levels (different levels and normal conditions) are the manipulated conditions, so the independent variable is the humidity level.
• b. Dependent Variable: The dependent variable is what is measured. The height of the redwood trees (measured once a week) depends on the humidity level, so the dependent variable is the height of the redwood trees.
• c. Control Variable: Control variables are factors kept constant. Factors like the type of redwood tree, amount of sunlight, soil type, etc., should be kept the same. So a control variable could be the type of redwood tree (or amount of sunlight, soil type, etc.).

Answer:

a. Independent Variable: Type of fertilizer (or application of fertilizer, including no fertilizer)
b. Dependent Variable: Number of flowers on each bush
c. Control Variable: Type of bush (or amount of sunlight, water, soil type, etc.)

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