Question 1
In this study, which factor was kept the same for every plot so that it could not explain the differences in soil loss?
Environmental Science Exam Prep
AP Environmental Science free-response questions: how they are scored
Three questions, 10 points each, earned part by part. A calculation earns one point for the setup and one for the answer; a proposed solution and its justification are separate points.
| Questions | 3 in 1 hour 10 minutes, 40% of the score |
|---|---|
| Question 1 | Design an investigation |
| Question 2 | Analyze and interpret quantitative data |
| Question 3 | Analyze an environmental problem doing calculations |
The task verbs
- Identify: name the answer. One word or phrase can earn the point.
- Describe: give the relevant characteristics, more than a name.
- Explain: say how or why, with the reasoning spelled out.
- Calculate: write the setup with numbers and units, then the answer.
- Propose a solution: a realistic action that addresses the stated problem.
- Justify: give a reason or an advantage beyond the one the question already names.
How to earn each point
- Answer the parts in order and label each one, so the reader finds it.
- For an investigation, name the independent and dependent variables, a control or a constant, and a testable question in their exact sense.
- For data, quote the numbers with units and the years or places they belong to.
- For a calculation, show the setup even when the calculator does the arithmetic: the setup is its own point.
- Each question is 10 points, so a short, exact answer to every part beats a long answer to a few.
Try 2 questions
Soil loss from four test plots
Four test plots of the same size were laid out side by side on one hillside with the same slope. Each was given a different surface cover, and the soil washed off each plot was collected and weighed for one year.
| Plot cover | Soil loss (metric tons per hectare) |
|---|---|
| Bare soil | 40 |
| Corn, plowed | 24 |
| Corn, no-till | 6 |
| Grass cover | 2 |
An experiment on carbon dioxide and shell growth
Students placed 30 snails of one marine species in each of three tanks of seawater. Each tank was bubbled with air containing a different concentration of carbon dioxide. All tanks were kept at 20 °C, and the snails got the same food. After 60 days, the students measured the average change in shell mass in each tank.
| CO2 in air bubbled in (ppm) | Average change in shell mass (mg) |
|---|---|
| 400 | +12 |
| 700 | +7 |
| 1,000 | +2 |
Question 2
What is the independent variable in this experiment?
Next step
College Board's past AP Environmental Science free-response questions and scoring guidelines
Questions people ask
How many points is each AP Environmental Science FRQ worth?
10 points each, so 30 in all, which is 40% of the exam score.
How long do you have for the AP Environmental Science FRQs?
1 hour 10 minutes for all three questions.
What are the three AP Environmental Science FRQ types?
Question 1, Design an investigation; question 2, Analyze and interpret quantitative data; question 3, Analyze an environmental problem doing calculations.