Labs - Environmental Science - page 361

Analyzing past exams can help you prepare for the AP Environmental Science exam. In this section, we
provide information is provided on the labs used in free-response questions and experimental-design questions
in the past. Review these sections to get a sense of how labs have been used on the exam in years past.
Free-Response Questions
Information from labs is frequently used in the free-response questions. Here is a brief description of the labs
or parts of labs that have been used in past free-response questions:
• In 1998, students were asked to determine the pH range for a fish species, explain how to determine that a
lake's pH has changed, and explain how to remediate the acidification.
• In 1999, students were asked to list three water quality tests and explain what information each water
quality test provides.
• In 2001, students were asked to draw a small food web from given information. In addition, points were
awarded for correct connections and energy flow between the species.
• Also in 2001, an information table was provided for four water quality tests and students were asked to
interpret the data. In addition, they had to provide two more water tests and the expected outcomes.
• In 2002, data from an LD 50 test on brine shrimp was provided, and students had to graph the data and de-
termine the threshold concentration and the concentration where 50 percent of the test species died.
• In 2003, students were asked to describe what changes might occur if worms ate all the leaf litter. Some
of the changes would involve soil quality.
• In 2004, students were asked to describe one physical soil test and one chemical soil test.
• In 2005, students were asked about surface mining, especially regarding the replacement of the removed
soil.
• In 2007, students were asked about primary and secondary sewage treatment and disinfection.
Experimental-Design Questions
Labs are also used in experimental-design questions. Review the labs and develop a detailed approach to an-
swering this type of question. You will also find it helpful to review the introduction of this topic for more in-
formation regarding experimental-design questions.
Here is a brief description of the labs or parts of labs that have been used in past experimental-design ques-
tions:
• In 1999, students were given a study and asked to describe the hypothesis, identify the variable being ma-
nipulated, outline a procedure including what data they would collect, discuss the results, and relate the
results to the distribution of an insect population.
• In 2001, students were asked to define a hypothesis and design a controlled experiment testing the pro-
duction of acorns and the gypsy moth population.
• In 2003, students were asked to design a controlled experiment that demonstrates cause and effect in a
forest ecosystem. The experiment had to include the environmental factor that would be tested, the hy-
pothesis that would be tested, and the data that would be collected.