The College Board decided to define the AP Environmental Science course as having a laboratory component.
This means that the laboratories you've performed in your course will be tested on the exam.
The College Board decided to be flexible about the labs that should be covered in the course.
The variety of different labs that can be performed gives students opportunities to explore various topics in environmental science; this also allows instructors the freedom to adapt their course laboratories to their geographic locations, which can make the course more interesting for students.
You will be expected to be familiar with the method.
The College Board describes several skills that you will be expected to have gained through participating in laboratories in your course.
One experiment can turn into another without the formal recording of a hypothesis or results.
The scientific method was created in order to provide a basic outline for scientific investigation.
You've probably been in the lab a number of times and completed many different types of laboratories during your AP Environmental Science course.
You may have had to do a class presentation after you wrote lab reports and handed them in to your teacher.
Due to the fact that the College Board didn't give your teacher a list of required labs, the lab experiences you had in your AP Environmental Science course are probably wildly different from the lab experiences other students have had at different schools.
On the AP Environmental Science Exam, you could be asked a number of different types of questions in which the lab component from your class will be helpful.
You won't be able to get full credit just by remembering what you did in the lab.
Critical thinking skills are required to answer these questions.
A lab-related free-response question on the exam might look similar to the one below.
The county range management office has just received a federal grant to study the breeding success of hawks in your area and you have been chosen to design and perform the research.
The range office wants to know if the hawk population at the state prairie reserve is comparable to the hawk population on the federal land and private ranch land.
There are no controlled burns allowed in the state prairie reserve.
An illness in the herd caused it to be destroyed.
lightning strikes are quickly extinguished.
The federal land is rented out to local ranchers.
The management of these lands allows for a specific number of days to be grazed.
No cutting, even of damaged trees, is allowed.
Private lands can be managed.
You may be saying to yourself that you don't know anything about hawks or the prairie other than watching Little House on the Prairie reruns.
Think about what you know before you decide that you can't answer the question.
Reread the passage and then ask the questions.
One way to assess the health of a population is to see how many offspring they produce and how many survive to reproductive age.
For hawks, the number of offspring produced could be determined by counting the number of eggs laid, and the number of offspring that survive to reproductive age.
In answering this part of the question, you can cite the two methods, as well as any others you can think of.
You're asked to come up with a plan of action.
The success of the hawk population is dependent on the number of eggs laid and the number of nestlings that leave the nest.
The reason for this proposed line of action is that the more eggs laid by individuals, the better the health of the population.
Rates of egg-laying give information about the health of the females of the population and whether or not they are getting adequate nutrition.
It's important to keep in mind that most birds of the same species lay about the same number of eggs, but that the difference between clutch sizes may not be an indicator of health.
Each of the three areas has a way in which the land is managed.
You can't change the management practices that you've been given.
This is not as clear-cut.
None of the management plans operate on land that's left untouched.
You could set up a control at one of the reserves, but it might be difficult to attract hawks and start with an adequate base control number.
A library control is an option.
In a library control, you could determine the maximum number of eggs that could be expected based on previous years' data.
One of these controls would be acceptable.
You might propose a plan of action.
Each of the three management areas has 10 acres of random plots.
You will determine the locations of the hawks' nest after observing them in the plots.
You can determine the number of eggs in each clutch by examining each nest and using binoculars.
You will continue to make observations throughout the summer to determine how many birds are hatched and how many leave the nest.
The success of the hawks will be determined by the percent success rate of each nest and the overall area.
You will compare your data from the three areas.
Determine the maximum success rate of offspring production in hawks using library resources.
You can count the number of hatched birds by observing the nest and hatchlings.
Baby birds are banded for tracking.
The number of birds that leave the nest should be counted.
The success of the hawks can be determined by statistical analysis.
The plan of action is the longest answer in this section, but hopefully you can see that it wasn't difficult.
You didn't need to know much about hawks because you took the information you learned this year and applied it to the situation.
The next parts will require you to know more, rather than asking you to use your imagination.
Explain how the land management plan of each of the three areas would affect the success of the hawk population.
The state land is heavy in undergrowth and may have damaged trees.
The diversity of the plant population in this area would be low because of the grass.
Not many other plant species would grow new grass.
There will be a lot of new grass in this area because the federal land is grazed.
The federal land might not be as diverse as the fall grazed land due to the natural thinning of the grass.
At any time, the private land can be grazed.
A controlled fire can be used to remove dead grass, add nitrogen to the soil, and remove plants that compete with grass.
The private land may have more diversity than other land management areas.
You could theorize that the private land could be low in diversity.
You could make a presumption and be counted as correct.
The first choice might be better since you are given data on the fire practices.
The more vegetation diversity there is, the more choices for the herbivores in food and habitats.
The more successful the plants are, the more successful the herbivores will be.
The more successful the hawks are, the more they will be.
Let's think about part (d) as you're almost done.
The success of the management plan would be shown by the success of the hawk.
It can't be successful if the rest of the food chain isn't strong.
You're done, and you didn't need to know much about the prairie or hawks.
How to set up a field experiment, the concept of the food chain, and land management plans are some of the things you need to know.
Critical thinking could have been used to deduce the management plans.
Below, we have listed some of the common labs performed during an AP Environmental Science course, a summary of the procedures you might follow, and the take- home message of each.
You might have done some of the labs, but you probably haven't completed all of them.
It's a good idea to review all of the labs and understand their basic workings.
In the soil testing lab, soil is tested for physical and chemical properties, which give information about the soil's condition and suitability for crops, septic fields, or other purposes.
The factors are listed below.
When the soil becomes alkaline, iron is not needed for plant growth.
To determine the percent of each type of particle in the sample, use mesh screen, cheese cloth, and soil to settle in water tubes.
Clay has a bigger holding capacity than silt or sand.
Good soil is rich, light, and easy to work with, which is good for plant growth because roots can easily grow through it.
Sand and clay are qualities of organic soil.
Small particles of soil form larger clusters.
Water can be retained inside a cluster.
The organic material is high in vitamins and minerals.
When exposed to acid, different types of bedrock, such as marble, granite, and basalt, have buffering capacity.
The high calcium content of marble makes it a better buffer than other rocks.
Water can be tested from many different sources.
The LaMotte kit and the spectrophotometer type kit are examples of sample kits that have different tools.
The results of some of the tests are expected.
It's not necessary for you to memorize all the standards, but you should be familiar with them.
Measurement of water clarity is required for warm-water and cold-water fish.
There will be low clarity and little sunlight in the water.
A Secchi Disk can be used to measure Turbidity, but a more accurate measure can be made with a Turbidity Unit.
The levels in still water and flowing water should be less than 0.025 and 0.05, respectively.
There are no EPA standards, but normal is between 100 and 250 parts per million.
Unpolluted natural waters have a low concentration.
There is a correlation between high nutrient levels or lots of biological material ready for decomposition and high BOD.
It can run off into streams when applied to roads and parking lots.
Animal waste is one of the sources of excess Cl.
Hardness is a measure of salts composed of calcium, magnesium, or iron.
The majority of water testing kits test for CaCl2.
Hard water is more than 121 parts per million, and soft water is less than 20 parts per million.
The EPA limit for total solids is 10 percent of the suspended solids.
Sewage, industrial waste, or excess amounts of algae can cause an objectionable taste in drinking water.
They can't be used for irrigation because of the salt on the soil.
The EPA standard is 500 IU/L, but dissolved solids can be as high as 20,000 IU/L.
Adding a water sample to a specialized media can be used to perform new tests.
There should be no colonies of growth in the water sample.
Air quality can be assessed using different methods.
Sticky paper can be used to collect particulates from various sources, and then the paper can be examined under a microscope.
The smallest particulates can be seen in the white paper.
In this lab, an eco badge is hung or worn in order to collect data on tropospheric ozone.
As the amount of ozone increases, the sample becomes more intensely colored.
A commercial sampling device is used to determine the amount of carbon dioxide in an air sample.
Car exhaust, burning tobacco, or other pollutants can be tested.
Lichen can be used to judge air quality.
Lichens are sensitive to air pollution.
The fruticose types are the most sensitive, followed by the foliose and then the crustose.
A model of a scrubber can be created to remove sulfur from burning coal.
A calcium compound can be used to wash the air column.
Invertebrates can be counted in an area and plotted to assess their diversity.
Fall traps or sticky traps can be set and bait can be used.
The number of different insects captured is counted and divided into the total number captured to give an idea of the area's flora and fauna.
A key can be used to determine the number of species.
A similar setup can be used to determine the impact of an invader.
In this process native bugs can be trapped and set up in terrariums and the effects documented.
Power plants, landfills, or municipal waste treatment plants can be visited on a field trip.
There are so many possibilities.
Think about how these experiences can help you on the exam.
In this lab, students are asked to use their homes as a laboratory and perform an energy audit, examining the amount of electricity used by their families over a set period of time and then using appliance standards to determine which is the largest energy consumer.
Students suggested how their family's electrical energy needs could be reduced.
Students look at the food chain in the lab.
They identify the organisms that are producers, primary consumers, and secondary consumers and determine how many levels make up the food chain.
In this lab, models are built to model land formations, coastlines, tectonic plates, mining operations, or any number of other physical formations.
In modeling the tectonic plates, students can slide orbump together plate models that are lying on top of a substance representing the magma.
Students can see how subduction zones and volcanoes work.
Students can use other models to create a representation of a physical structure in order to better understand it.
Students can build a model of a mine to represent the rock layers and mineral deposits.
In this lab, students use a kit or a lab procedure to test the concentration of LC orLD that will cause the death of 50 percent of the test organisms.
This procedure is used to test the effects of copper on Daphnia, a tiny species of freshwater crustacea.
Daphnia are fed fluorescently tagged sugar after being exposed to a range of Cu levels.
Daphnia are blue under the UV light.
The experiment can be done in a number of different ways.
One way to mark off two plots is to remove the vegetation from Plot 1.
For an additional period of time, Plot 2 is left to grow.
The investigation may be done in the lab with grass squares or bottles of algae.
The vegetation is weighed and dried.
The baseline data for the amount of biomass present at the beginning of the experiment is provided.
After the time period of growth for the second plot, the vegetation is removed from the first plot and treated the same.
This gives information about the increase in the experimental time period.
Productivity of vegetation is another way this can be expressed.
Productivity is calculated by subtracting the initial growth from the experimental growth.
This is the net productivity for the plot.
The grass in the second plot is producing a substance called photosynthate.
The number you calculate is the net, not the gross, productivity, because some of this photosynthate must be used to support the needs of the plant.
If an experiment is performed with bottles of growing algae or duckweed, the gross productivity can be determined.
The starting plant material in one of the bottles is covered with foil to prevent light from entering the bottle.
The plants are only able to breathe in this bottle.
At the end of the experiment, the bottle should have less biomass than the initial plant material because the plants have to use stored sugar.
The gross productivity is given when the metabolic rate information is added to the net productivity.
Sample plots can be used to examine the patterns of plant growth or dispersal.
Unless a garden was used as the sample plot, the target plant will most likely be dispersed in clumps.
Random dispersal is not typical in nature, and distribution is usually only found in plots planted by humans.
Population growth experiments can involve fast-growing populations such asbacteria, duckweed, roly-polies, or fruit flies, as well as the analysis of human population data.
Population growth can be plotted with time along the x- axis and on the y- axis.
Initially, the curve is a J shape.
The hook on the J is extended due to the lag time in growth as thebacteria acclimate to the new media.
In population growth experiments, other variables are added to samples ofbacteria to compare the growth of a normal population to one that has been altered.
This can be used to assess the effects of extra nutrients on the organisms.
Turbidity can be observed and recorded when studyingbacteria.
Growth has taken place if the tube is turbid.
Turbidity can be seen with a spectrophotometer.
The amount of light that passed through the sample tube is measured by the instrument.
The size of a population of a species is studied in this type of lab.
A population is a group of individuals in the same area.
Colored stickers and a collection box can be used in the experiment.
On the first day, caterpillar are captured and marked.
The new and recaptured individuals are marked on the second day after they are captured.
An estimate of the population that was originally captured can be obtained by dividing the number of recaptured insects by the size of the population.
The number of caterpillar captured is counted on the third day.
The total number of caterpillars captured on day three is divided by the number from day two to get an estimate of the population.
Students in this lab determine if salt levels affect seed germination.
Students use various salts to saturate a growing surface.
Salt levels are determined by the amount of seeds sown.
salinization is mimicked in this lab.
If you count the graph blocks, you can determine an appropriate scale.
The time is usually plotted on the x- axis.
Take Practice Test 2 after studying the words in the Glossary.
You can get sample multiple-choice and free-response questions on the College Board website.