Part A: Preparing for the Field Trip
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As you plan for your trip, follow the guidelines in the Lab Tips box and the field trip tips.
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You will make observations in the field and in the classroom. Prepare a data table similar to the one below to record observations.
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Make sure you are familiar with the six-kingdom classification system explained in Section 18-3.
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Write a plan that describes a procedure for your field trip. Have your teacher review the plan for practicality and safety.
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At home, select some food items to bring to class just before your field trip. These will be left unrefrigerated to speed growth of microorganisms.
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Before going on the trip, set aside the food items you brought in a place designated by your teacher. Dry foods such as beans or bread should be placed in a container with some moisture. Also, set aside a large plastic cup of water.
Part B: Working at the Site
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At the site, look in a variety of places with different characteristics to find the largest variety of organisms. Look in sunny areas, in the shade, in the water, in the air, behind plants, between the blades of grass, within a forest, at the edge of a forest, and so on. When you locate an organism, record your observations in your data table.
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Supplement your observations with drawings or photographs. Keep in mind that when you take photographs outside, using a flash may sometimes be necessary. Place the row number from your data table on each drawing, photograph, or container to help keep your observations organized.
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Here are some hints for filling in your data table:
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The organisms you see in the field will all be macroscopic (able to be seen without a microscope). This usually tells you that the organism is multicellular.
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When you look for locomotion, you are looking for movement by an animal, not motion because of wind or other objects.
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As you examine an organism's color, look for signs of the green pigment chlorophyll and note if it is present. The presence of chlorophyll is typical of plants and some protists.
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In your description, include information such as where the organism is found. If the organism is found on another living thing, for example, it may be using it for food as fungi do.
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Indicate whether the organism has appendages. Animals may remain still when you look at them, but the presence of wings or legs is a sign they can move.
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Note if the organism is anchored. Plants and fungi are generally anchored, but some animals such as sponges or barnacles are anchored, too. Look for an opening it uses for taking in food.
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Try to collect the following samples to bring back to the classroom: water from ponds, lakes, streams, oceans, or puddles; soil and sand; natural mulch or leaves; and small plants or parts of plants. Wash your hands with soap and warm water.
Part C: Following the Field Trip, Day 1
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If you collected moist soil, set up the apparatus shown below to collect roundworms and other tiny animals. Put a piece of rubber tubing on the end of a large funnel. Place a hose clamp on the rubber tubing. Hang the funnel through an iron ring on a ring stand.
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Double a piece of cheesecloth and place a sample of soil in the middle. Then tie it closed to make a small sack. Put the sack in the funnel. Then pour enough water into the funnel to fill it almost to the top. Leave the sack in the water for 24 hours.
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If you collected sand or dry soil, place a sheet of white paper in a dissecting tray and spread a thin layer of the sand or soil on the paper. Examine the thin layer of soil with a magnifying glass. Look for signs of life. If you find any organisms, record your observations in your data table and draw diagrams or take a photograph of what you find.
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If you collected mulch or leaves, place a clean piece of white paper in a dissecting tray and repeat the procedure you used in step 13 with a portion of the leaves or mulch.
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Fallen leaves and mulch often contain microorganisms that can be rinsed off for study. Take some moist leaves or mulch from the bottom of the pile and place them in the cup of water you set aside in step 6. Leave them overnight.
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To examine water samples you collected, prepare a slide as follows. Using a dropper pipette, withdraw water from the top of the water sample. Place a drop in the center of a clean slide. Then cover the drop with a coverslip. If you pick up any macroscopic organisms with your dropper pipette, use a depression slide rather than a plain glass slide.
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Prepare two more slides with water from the middle and bottom of the sample.
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Examine the slides under low power. If necessary, switch to higher power for a closer look. Record your observations in your data table and draw diagrams of what you find. Wash your hands with soap and warm water.
Part D: Following the Field Trip, Day 2
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Examine the food substances from step 5 for the presence of organisms. Look for fuzzy growth on the surface of the food. Examine the fluid surrounding the food using the process in steps 16–18. Record your observations in your data table and draw diagrams of what you find.
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Examine the water in the funnel you set up in steps 11 and 12. Look for the presence of soil organisms as follows. Place a beaker under the rubber tubing and open the hose clamp for an instant to release some water.
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Using a dropper pipette, put a few drops of the water onto a depression slide. Cover the slide with a coverslip. Locate some organisms under low power. Then switch to high power. Record your observations in your data table and draw diagrams of what you find.
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Prepare a slide from the beaker of water containing leaves or mulch from step 15. Using a dropper pipette, put a drop of the water onto a glass slide. Cover the slide with a coverslip.
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Locate some organisms under low power with a microscope. Then switch to higher power. If you don't find any organisms, make new slides each day for a week. As the organisms reproduce, your chance of finding them will improve. Record your observations in your data table and draw diagrams of what you find. Wash your hands with soap and warm water.
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Classify each kind of organism you observed using the dichotomous key below. Note any problems with the key as you work. Record the kingdom in your data table.
