The common labs used on the AP Environmental Science exam are in this section.
There are no specific labs for the exam and the labs may vary from year to year.
Look at the basic principles behind each lab.
The labs will help you understand the curriculum.
Acid rain is caused by sulfur and nitrogen compounds emitted by burning fossil fuels.
Sulfur dioxide and nitrogen dioxide react with water to form acid.
The basic setup for this lab uses a combustion chamber to collect gases from burning fossil fuel and to test the pH of the gas.
The result is a lower pH.
There are several ways to collect particulates from the air, including attaching a white sock to the tailpipe of an older car or diesel vehicle.
Another method of trapping particulates in the air is to hang a sticky paper outside and collect it after a few days.
If you want to see the particulate material, you can use a magnifying glass or microscope.
The particulate may be large particles.
In this lab, you can use a commercial ozone detector, an ecobadge, or a homemade potassium iodine gel to collect data on ground-level ozone.
As the concentration of ozone increases, the ecobadge will become more intensely colored.
Car exhaust, burning charcoal, or another potential source of carbon dioxide can be tested with a commercial sampler.
Students are learning how to convert vegetable oil into biodiesel that can be used in cars and generators.
The procedure for using new or used oil is the same.
The students will create diesel fuel called "biodiesel" at the end of the procedure because the source is vegetable.
The lab looks at the diversity of insects in the area.
A trap is set up.
The total number of species and the total of each species are used to calculate the total number of insects.
The equation H is used to calculate the Shannon-Wiener Index.
H is the number of organisms of a particular species to the total number of organisms, pi is the ratio of the number of organisms to the total number of organisms, and ln pi is the natural log of pi.
Fall traps, sticky paper, or bait traps can be used.
The lab can be completed at home or in the classroom.
Students monitor the results of their composting on a weekly basis, keeping track of how much compost they add by weight and type.
Students collect the compost, analyze it, and develop a procedure to test it using plants.
The activity requires a lazy Susan, three pieces of paper, and markers.
Draw a line from the center to the edge on the first sheet of paper.
Draw a line from the center to the edge of the paper.
Draw a final line from the center to the edge after a third turn.
There will be three straight lines because Susan is not moving.
Place a second piece of paper on the lazy Susan and then move the platter counter-clockwise.
While the platter is moving, draw three lines from the center.
As you draw the lines on the paper, the lines will come out curved.
This procedure can be repeated except for rotating the lazy Susan clockwise.
Eco-columns are mini ecosystems made up of three chambers.
There is a fish and plant in the bottom section.
The students will be able to test the water with a small slit in the chamber.
The middle section can be reversed with the top section.
The aquatic section contains worms and organic matter that are broken down in the decomposition section.
The section has a small plant and animal.
The top has a small cap that can be used for watering.
The system usually doesn't need water after a few weeks.
The column shows the water cycle.
Students learn to identify which cycles are in the column when they find other biogeochemical cycles.
The activity teaches observation skills.
When students answer questions about their lifestyles in an online survey, they see their impact on the Earth.
Students can take the survey multiple times to see how their lifestyles may change.
The field experiment gives students the chance to learn how to use common environmental measurement instruments and examine the biotic and abiotic components of a local environment.
Students look at plants, consumers, decomposers, elements, and compounds.
Depending on the design, the data can be recorded two to four times.
The flow of energy throughout the system is noted.
Students look at energy usage at home or school to figure out ways to save energy.
To determine how much energy is used in kWh, you can look at the home energy bill.
To see the number of light bulbs in the house, how many are already in use, dimmer used, how many are compact fluorescent lights (CFLs), or how many are inefficient, a survey can be conducted.
Students can watch a meter to compare energy use when an appliance is turned on and off.
The students develop a plan to use less energy.
Field studies might include determining the types of plants and animals in the area, as well as the role of the water, weather, terrain, and human influences.
Water quality, air quality, soil studies, and transects may be included in additional studies.
Food webs are shown in several activities.
Students identify producers, primary consumers, secondary consumers, and tertiary consumers.
Students show the energy flow from the lower to the higher trophic level and to the decomposers.
Students can discuss the ramifications of removing one species with the help of exploring webs.
Students build a model of a mine and try to mine it from a partner's model.
The goal is to maximize the amount of resources collected and minimize the damage done to the mine.
The activity can be done with chocolate chip cookies.
Most labs for AP Environmental Science are actually lethal concentration labs, in which test organisms are placed in a known concentration of the test medium.
The organisms receive a lethal dose.
For different criteria, the number can be changed.
Brine shrimp can be used with copper sulfate.
The brine shrimp are placed in copper sulfate solutions.
After 24 hours, a count of live and dead brine shrimp is made and the number of dead shrimp is plotted on a graph.
The threshold and lethal concentration can be determined from the graph.
This activity involves cleaning up an oil spill.
A pie tray has vegetable oil in it.
A straw blows the oil around in the ocean.
Students try various methods to remove the oil and leave the water behind.
Small straws and string can be used as booms to surround the water.
Cotton balls and pads, cloth, newspaper, and other materials can be used to absorb oil.
Students can see how much oil remains on the pie tray when the water is dumped out.
This lab shows the relationship between predator and prey.
When predator numbers decline, prey numbers increase.
More prey leads to more predator, and fewer prey leads to fewer predator.
The lab is conducted with pieces of paper.
A pattern of population numbers should emerge after each round of data.
In this lab, grass captures energy from the sun through the process of photosynthesis, resulting in a measured increase in the grass's primary productivity.
The gross primary productivity is the amount of energy produced by the sun.
The net primary productivity is the amount of sugar produced by the plant when it is in motion.
Lemna minor, also known as duckweed, is a plant that can be used as an aquatic test plant for new pesticides.
It can be used as feed for chickens.
This lab is used to measure the growth of duckweed in waters with varying concentrations of nitrates, phosphates, pesticides, or salts.
Different soil samples are collected in the lab.
Gravel, sand, and fine sand are usually included in samples.
The length of time it takes for water to reach the bottom is recorded.
The activity shows how porous and permeability increase with larger particles.
The chance of flooding is higher if the soil has tighter pores and smaller particles.
The Central Valley of California has a problem with the build up of salts in the soil.
Students in this lab grow seeds in increasing concentrations of salt to determine the point at which the seeds stop growing.
Fast-germinating seeds such as Mung beans can be used because you can see results in about five days.
Salt concentrations begin at 0 percent and are increased up to 4 percent in small amounts.
The data can be graphed.
Students conduct physical and chemical tests on soil samples.
The results help determine if the soil is suitable for growing crops.
Students are directed to build buildings, bury systems, and conduct additional activities in the lab.
The concentration of H + and OH - ion is measured.
The scale has a range of 1 to 14 with 7 being neutral.
Values below 7 are acidic and values above 7 are basic.
Some soil types need to be mitigated.
Plants won't be able to use some nutrients in low-pH soils.
Also referred to as potash.
The soils that are moist are darker than the soils that are dry.
The presence of iron and/or other minerals can be seen in other soil colors.
The soil can be crumbled into smaller pieces with little pressure.
This is important for the roots of plants.
It is easier for plant roots to grow if the friability is greater.
The percent humus test is used to determine the organic component of the soil.
Permeability is the measure of how much fluid can flow through the soil.
The connection between soil particles can be determined by looking at the size of the pores.
Roll a sample of moist soil beneath your fingers, the longer the roll, the greater the percentage of clay.
The percentage of clay, silt, and sand is determined by placing a mixture of soil in a cylinder, allowing the soil sample to settle, and then determining the percentage of each.
Sand settles first, followed by silt and finally clay.
According to the soil texture triangle shown in Figure C-5, the percentages of each are used to determine the soil type.
The water-holding capacity is the amount of water held by the soil.
Sand has the least, while clay has the most.
While designing a solar house or solar cooker that uses the sun's rays to trap heat, this activity allows for creativity and innovation.
Lab objectives include defining the difference between active and passive solar energy, learning how both can be utilized, and discovering how to identify the important components of each.
The sun's radiation can be used to power electrical or mechanical equipment.
Passive solar power doesn't use mechanical systems.
Passive systems are simple and have minimal moving parts, while active systems use fans, pumps, and other technology.
Understanding how this energy is best captured is important with the increasing use of solar energy.
The amount of heat needed to raise the temperature of 1 gram of a substance by 1degC is called specific heat.
The amount of solar radiation needed to heat a substance depends on the material.
The heat-holding capacity of various substances is tested in this lab.
Specific heat is applied to the atmosphere and climate.
This particular lab compares the heat of soil to that of water and then relates the results to the climate.
Any resource that is shared by a group is called the commons.
This includes the air we breathe, water we drink, and fish taken from the ocean.
It also means city parks and other things that are shared by a group or are used by the public.
In this activity, students "fish" from a common ocean of fish (goldfish crackers, M&M's, or other similar products may be used) and usually all the "fish" are taken on the first round.
Students learn to cooperate to save the ocean.
Scientists sample small sections and then use the data to represent likely conditions in the area as a whole.
A 100m tape line is one method of sampling.
At every 10m interval, a 1- square-meter area is placed first on the left side of the tape and then on the right side.
The percentage of ground cover is estimated in each square-meter area.
The percentage of each plant is determined after the plant species is identified.
Evidence of animals in the square is recorded.
The information is compared to other areas in the study area.
This is an excellent activity to do on a regular basis.
Water quality can be tested with a variety of tests.
The concentration of either free H + or OH - ion is measured.
The normal freshwater pH is between 6.5 and 8.
The saltwater has a pH of 8.2.
The temperature is the heat content of the water.
Dissolved oxygen is a measure of the amount of oxygen in the water.
The concentration of DO is influenced by temperature.
Other factors that can affect the concentration of DO in water include the amount of organic waste, the plant and animal communities present, the water depth, and the flow rate of rivers and streams.
There is an average needed DO concentration for freshwater and saltwater fish.
Percent saturation is the amount of oxygen dissolved in the sample water compared to the maximum that could be present at that temperature.
The maximum amount of DO that the water can hold is one hundred percent saturation.
Excellent DO percent saturations are between 80 and 120 percent.
The clarity of the water is Turbidity.
The test can be done using a Secchi disk, which divides the quarters into black and white squares.
In areas where the water is clear, a colored disk can be used.
Turbidity is a measurement of dissolved particles in water.
The water is less clear because of the high amount of suspended solid material.
The food chain can be affected by this because it reduces the penetration of sunlight and the amount of sunlight in the water.
It is important for plant growth to havephosphate, which is found infertilizers and the water from agricultural lands.
Excess growth can be caused by excessively high phosphate levels.
In flowing water, the level ofphosphate should be less than 0.025 in still waters.
Nitrogen is important for plant growth and can be found in agricultural lands.
Eutrophication can be caused by excessive nitrogen levels.
The EPA's limit for a concentration greater than 10 grams per liter is considered high.
The alkalinity is the amount of compounds that can change the pH.
The normal range is between 100 and 250 parts per million.
The EPA does not have standards for alkalinity.
The Biological Oxygen Demand is a requirement for aerobic organisms in a body of water.
Unpolluted waters have a low concentration.
There is a correlation between high nutrient levels and high BOD.
Fecal coliform is a type ofbacteria that ferments and produces gas.
There are new tests that can change the color of gas.
Problems can arise from suspended sewage, industrial waste, soil erosion, and excess amounts of algae.
It's possible that total dissolved solids are objectionable in drinking water.
Salts can accumulate over time and make water unsuitable for irrigation.
The EPA's standard for dissolved solids per liter of water is 500, but the range is 20 to 2,000.
Driving on snowy and icy roads in the winter is easier and safer with the use of NaCl.
Local chlorine concentrations can increase when salts run off into the streams.
Animal waste is one of the sources of chlorine.
limestone formations may be affected by chlorine.
Measures dissolved salts that include calcium, magnesium, or iron.
Soft water is less than 20 parts per million.
The normal range of iron is 0.1 to 0.5 parts per million.
The lab tests the effects of acid rain on rock.
Observations are made to see how acid on the rock affects it.
The mass of the rock can be measured before and after exposure to acid.
This activity can be repeated to see the long-term effects on the rock.
Chemical weathering can include dissolving reactions.
In this lab, rock samples are shaking in a container of water.
Rock is weighed, placed in a container with water, and then drained.
The difference in mass is calculated after the rock is dried and weighed again.
Wind, water, ice, plant growth, and human-related actions are examples of mechanical weathering.
It is possible to prepare for the AP Environmental Science exam by analyzing past exams.
Information on the labs used in free-response questions and experimental-design questions in the past is provided in this section.
To get a sense of how labs have been used on the exam in the past, review these sections.
The free-response questions often use information from labs.
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 fix the acidification.
In 1999, students were asked to list three water quality tests and explain what they found.
Students were asked to draw a food web in 2001.
Points were awarded for correct connections and energy flow between the species.
Students were asked to read the data from the four water quality tests in 2001.
They had to provide two more water tests.
Students had to graph the data and determine the threshold concentration and the concentration where 50 percent of the test species died in 2002.
Students were asked in 2003 what would happen if worms ate all the leaf litter.
Some of the changes would involve the quality of the soil.
In 2004, students were asked to describe a physical and chemical soil test.
In 2005, students were asked about surface mining and the replacement of the removed soil.
In 2007, students were asked about sewage treatment.
Experiments and design questions use labs.
Take a look at the labs and see if you can answer this type of question.
You can review the introduction of the book to learn more about experimental-design questions.
In 1999, students were asked to describe the hypothesis, identify the variable being manipulated, outline a procedure, 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 an experiment to test it.
In 2003 students were asked to design an experiment that demonstrated cause and effect in a forest.
The experiment had to include the environmental factor that would be tested, the hypothesis that would be tested, and the data that would be collected.