1.
You are the head of the research division of the Leafy Lettuce Company. Your company is experimenting with growing lettuce using hydroponic technology. Hydroponic technology involves growing plants in containers of growth solution in a greenhouse. No soil is used. The growth solution that the company uses contains water, nitrogen, and phosphorus. The company wants to know if adding iron to this formula will improve lettuce growth.
What would the INDEPENDENT VARIABLE be in the experiment?
Correct Answer
C. The growth solution
Explanation
The independent variable in this experiment would be the addition of iron to the growth solution. This is because the company wants to test if adding iron to the formula will have an effect on lettuce growth. The growth solution is the variable that is being manipulated or changed in order to observe its impact on the lettuce growth.
2.
In scientific research, the DEPENDENT VARIABLE is a factor that is measured to learn the effect of one or more independent variables.
Correct Answer
A. True
Explanation
The dependent variable in scientific research refers to the factor that is being measured or observed in order to understand the impact or influence of one or more independent variables. It is the variable that is expected to change or be influenced by the independent variables. Therefore, the statement that the dependent variable is measured to learn the effect of independent variables is true.
3.
In an experiment, you water three sunflower plants with salt water. Each plant receives a different concentration of salt water solution. A fourth plant receives pure water. After a two week period, the height of each plant is measured. In this experiment, the plant height is which of the following?
Correct Answer
B. The DEPENDENT variable
Explanation
The height of each plant is the dependent variable in this experiment because it is the variable that is being measured and is expected to change as a result of the different concentrations of salt water solution. The independent variable in this experiment is the concentration of salt water solution, as it is being manipulated by the researcher. Qualitative data refers to non-numerical data, which is not relevant to this experiment.
4.
The following could be an example of a hypothesis: "If the outdoor temperature decreases to 32 degrees Farenheit or colder (at standard pressure), then the lake will begin to freeze because water freezes at 32 degrees Farenheit."
Correct Answer
A. TRUE
Explanation
The given statement is an example of a hypothesis because it presents a proposed explanation or prediction that can be tested through observation or experimentation. It follows the format of an "if-then" statement, stating that if the outdoor temperature decreases to 32 degrees Fahrenheit or colder, then the lake will begin to freeze because water freezes at 32 degrees Fahrenheit. This hypothesis can be tested by observing whether the lake actually freezes when the temperature reaches 32 degrees Fahrenheit or colder. Therefore, the answer is TRUE.
5.
There will be a statistically significant difference in graduation rates of at-risk high-school seniors who participate in an intensive study program as opposed to at-risk high-school seniors who do not participate in the intensive study program." (LaFountain & Bartos, 2002, p. 57)
What is the DEPENDENT variable?
Correct Answer
A. Graduation rates
Explanation
The dependent variable in this study is the graduation rates. The study aims to determine if there is a statistically significant difference in graduation rates between at-risk high-school seniors who participate in the intensive study program and those who do not. The graduation rates are the outcome that is being measured and compared between the two groups.
6.
There will be a statistically significant difference in graduation rates of at-risk high-school seniors who participate in an intensive study program as opposed to at-risk high-school seniors who do not participate in the intensive study program." (LaFountain & Bartos, 2002, p. 57)
What is the INDEPENDENT variable?
Correct Answer
C. Participation in the intensive study program
Explanation
The independent variable in this study is participation in the intensive study program. The study aims to investigate the impact of this variable on the graduation rates of at-risk high-school seniors.
7.
"A director of residential living on a large university campus is concerned about the large turnover rate in resident assistants. In recent years many resident assistants have left their positions before completing even 1 year in their assignments. The director wants to identify the factors that predict commitment as a resident assistant (defined as continuing in the position a minimum of 2 years). The director decides to assess knowledge of the position, attitude toward residential policies, and ability to handle conflicts as predictors for commitment to the position." (LaFountain & Bartos, 2002, p. 8).
What is the INDEPENDENT VARIABLE?
Correct Answer
B. Knowledge of the position, attitude toward residential policies, and the ability to handle conflicts
Explanation
The independent variable in this scenario is the combination of knowledge of the position, attitude toward residential policies, and the ability to handle conflicts. These factors are being assessed by the director as potential predictors for commitment to the position of resident assistant. The director wants to determine if having a certain level of knowledge, a positive attitude towards policies, and effective conflict resolution skills can predict whether a resident assistant will stay in the position for at least 2 years.
8.
According to the graph, the value of Sarah's car INCREASED between 2001 and 2007.
Correct Answer
B. False
Explanation
According to the graph, the value of Sarah's car did not increase between 2001 and 2007.
9.
Tyrosine concentration ([Tyrsonine] mM) is shown as the DEPENDENT VARIABLE in this graph.
Correct Answer
B. False
Explanation
The correct answer is False. The reason for this is that the dependent variable in the graph is not specified. The graph could be showing the concentration of any substance other than tyrosine, or it could be showing a different variable altogether. Without further information, it is not possible to determine the dependent variable from the given graph.
10.
The diagram below represents the change in a sprouting onion bulb when sunlight is present and when sunlight is no longer available.
A student researcher hypothesized, "if the leaves of an onion bulb are removed from light for an extended period of time, then the leaves will wilt, or wither, because the leaves require sunlight to remain healthy." The above diagram, which models the results of his experiment, SUPPORTS this hypothesis.
Correct Answer
A. True
Explanation
The diagram shows that when sunlight is present, the onion bulb sprouts and grows healthy leaves. However, when sunlight is no longer available, the leaves wilt and wither. This supports the hypothesis that the leaves require sunlight to remain healthy. Therefore, the correct answer is true.