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 will have an effect on lettuce growth. By manipulating the presence or absence of iron in the growth solution, the company can determine its impact on the lettuce's 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 is a factor that is measured in scientific research to understand the impact of one or more independent variables. It is the variable that researchers are interested in studying and analyzing to determine how it is influenced by the independent variables. By measuring the dependent variable, researchers can gain insights into the relationship between the independent variables and the effect they have on the outcome being studied.
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
In this experiment, the height of each plant is being measured. The height of the plants is dependent on the concentration of salt water solution that they receive. Therefore, the height of the plants is the dependent variable, as it is the variable that is being measured and is expected to change in response to the different concentrations of salt water. The independent variable in this experiment is the concentration of salt water solution, as it is being manipulated by the experimenter to see its effect on the dependent variable. Qualitative data refers to descriptive observations and is not applicable in this scenario.
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 based on observations and reasoning. It follows the format of an "if-then" statement, stating that if the outdoor temperature reaches 32 degrees Fahrenheit or colder, then the lake will begin to freeze because water freezes at that temperature. This statement can be tested and potentially proven or disproven through experimentation or further observation. 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 an intensive study program and those who do not. The graduation rates are the outcome or response variable that will be 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 the participation in the intensive study program. This variable is being manipulated by the researchers to determine its effect 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 "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 of commitment to the position of resident assistant for at least 2 years. The director wants to determine if having knowledge of the position, a positive attitude toward residential policies, and the ability to handle conflicts effectively will increase the likelihood of a resident assistant staying in their position for a longer period of time.
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. It either remained the same or decreased during that time period.
9.
Tyrosine concentration ([Tyrsonine] mM) is shown as the DEPENDENT VARIABLE in this graph.
Correct Answer
B. False
Explanation
The correct answer is False because the graph does not provide any information about the concentration of Tyrosine. The dependent variable is not shown in the 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 sprouting onion bulb is healthy and growing. However, when sunlight is no longer available, the leaves of the onion bulb wilt and wither. This supports the student researcher's hypothesis that the leaves require sunlight to remain healthy. Therefore, the correct answer is true.