Collecting Biological Data
Question/ Problem: What life characteristics can be observed in a pill bug?
Objectives:
Observe whether life characteristics are present in a pill bug
Discuss procedures for measuring and recording data
Discuss proper care of living organisms during an experiment
Hypothesize methods for making and studying quantitative and qualitative characteristics of an organism during an experiment
Create neat, organized, labeled charts, tables, and graphs of data for analysis.
Materials:
For Experiment 1: Pill bug toothpick watch glass or petri dish
Metric ruler dissecting microscope clock/watch with seconds
Procedure:
Write your hypothesis in your notebook. (Remember to make it a statement with a reason or explanation that answers the problem)
Carefully obtain a pill bug from your teacher.
Experiment 1:
- Observe your pillbug with your naked eye, a hand lens and under a dissecting microscope.
Record a list of qualitative observations of your organism. A qualitative observation is a descriptive observation.
Record a list of quantitative observations of your organism. A quantitative observation is a numerical observation.
Make an accurate, neat, colored drawing of the organism. This drawing should be larger than the actual size. (Multiple angles can be useful)
Describe any sensory structures (organs) that the organism possesses. Be sure to go back and label these structures on your drawing.
Measure in millimeters the length and width of your pill bug and label this on your drawing. Post your measurement for length on the board with the rest of the class data.
Construct a bar graph of everyone’s data for length. Be sure to label the title, axis, and units of measurement.
Experiment 2:
Gently touch the underside of the pill bug with a toothpick. It may be necessary to gently flip the pill bug over with the pencil to get at its underside. Caution: Use care to avoid injuring the pill bug.
Record a description of the pill bugs response.
Record the time, in seconds, how long the pill bug remains curled up. Repeat this four more times. Then calculate the average response time
Answer lab questions 1-5 before beginning experiment 3.
Conclusion: Follow the directions on how to write a laboratory report. Be sure to explain which parts of your hypothesis are supported, which are not supported, and which need further investigation. Be specific and give detailed reasoning and experimental data to support your conclusions.
Collecting Biological Data: Lab Report Template
Purpose:
This should be a one or two sentence explanation of the objectives and the problem being tested.
Hypothesis: Answer the problem (give your reasoning).
Procedure:
Experiment 1: See lab handout.
Experiment 2: See lab handout.
Data:
Experiment 1:
Quantitative Observations
|
Qualitative Observations
|
See below for suggestions
List things you can count...
Number of legs, eyes, antennae, segments
| Length in mm | Width in mm |
| Small | mm | mm |
| Big | mm | mm |
|
See below for suggestions
What does it look, feel, smell, sound like?
Describe its color, shape, form, behavior, odor and feel.
|
Labeled Diagram(s) of Pill Bug:
(This may be attached at the end, but then write see attached in this spot)
Bar Graph of length:
(Use excel to graph the class data)
Experiment 2:
Trial
|
Time (seconds)
|
Pill Bug Response
|
Researchers notes
|
|
|
|
(ex. Sources of error, changes in experiment, bug, etc.)
|
|
|
|
|
|
|
|
|
|
|
|
|
Average Time:
|
|
|
|
OR
| Large Pill Bug |
| Small Pill Bug |
|
| Trial | Response Time | Trial | Response Time |
| 1 |
| 1 |
|
| 2 |
| 2 |
|
| 3 |
| 3 |
|
| 4 |
| 4 |
|
Experiment 3:
(Design your own data table(s) to record relevant information. Don’t forget titles!)
Laboratory Questions:
Which characteristic(s) of life did the, quantitative & qualitative observations help you to identify?
Which characteristic(s) of life did the drawings help you to identify?
Which characteristic(s) of life did experiment 1 help you to identify?
Which characteristic(s) of life did the response time chart help you to identify?
Which characteristic(s) of life have you not observed in the pill bugs at this time?
Which characteristic(s) of life did experiment 3 help you to identify?
Conclusion: This is an explanation of what you learned!
Paragraph 1: Intro. Restate your hypothesis and say which parts of your hypothesis are supported, which are not supported, and which need further investigation.
Paragraph 2: Evidence and arguments. Take each part of your hypothesis that was supported and explain how your data supports this conclusion. Then take each part of your hypothesis that was not supported and explain how your data shows that your guess was wrong. Be sure to include what is now the correct conclusion. Then take each part that you got no information about and explain how you would test this characteristic of life. (Double check: Did I use all 6 characteristics of life in paragraph 2? If not go back. Did I use all the pieces of data in my explanation in paragraph 2? If not go back.)
Paragraph 3: Summary and Final conclusion. Summarize what your conclusion is from paragraph 2. Include any explanations for why you may have gotten different results than you expected. These explanations may include sources of error that occurred during the experiment. (This does not mean that you can say “I did the lab wrong”, you must explain what went wrong and why that may have affected the outcome of your results/conclusions.)
Background Info
These are sow bugs, don't get these. They don't roll up.
These are pill bugs, notice the difference
The pill bug (also called the wood louse and the roly-poly bug) is a small, segmented land creature that can roll into a tiny ball for protection. The pill bug is NOT an insect, but is an isopod (another type of arthropod).
Collecting Live Insects
Where to find
Look under logs, moist leaf litter, flower pots (a day after they have been watered), outdoor pet dishes, and under paving bricks or stones. Isopods live where it is moist and usually in a shaded area. To attract them, water soil or leaf litter in the shade and cover with plastic, piece of plywood or cardboard.
Traps made by hollowing out apples or potatoes may be used to catch them. Keep the area moist and check under the covering in a couple days. If you are unable to find isopods they can be purchased from: Carolina Biological Supply Company.
How to collect
Before looking for isopods, prepare a container and tools to gather the isopods. To collect them, use a spoon or shovel and a container. Look under a rock or log and be prepared to collect the isopods quickly before they scurry away from the light. Gently scoop up soil with the isopods and place them in the container. Look on the underside of the log or stone for others. They can be gently picked or brushed off with a finger into the container. Pill bugs often curl up and can be picked up individually or scooped up with the spoon. If you are going to keep the isopods a couple days before placing them in the classroom, use a plastic container with small holes poked in the lid and a moistened piece of paper towel or sponge lightly crumples inside. Use an old pie tin to sort the isopods from the soil before placing them in the container. The paper towel must be kept moist or they will die. When you are looking under rocks and logs be careful to avoid scorpions, centipedes and other animals that live there. Return the rock or log to the way it was when you found it.
How to Keep
A raw potato can be provided for food. Food should be removed if it shows any sign of mold and replaced with sliced carrot, potato, or apple.
If you are keeping them for a longer period of time, place them in a terrarium with rich, moist soil. Place moist paper towels in the container to provide humidity. Continue to add vegetables, replacing them as necessary to control mold. Keep container at room temperature in low light.
Classroom habitat. Isopods are excellent classroom animals—they exhibit interesting behaviors, they are small but not tiny, they don’t bite, smell, fly, or jump, and they are easy to care for. Isopods can live in just about any vessel, from a recycleasd margarine tub to a 50-liter aquarium. If the container is smooth-sided, it doesn’t even have to be covered, because isopods can’t climb smooth surfaces at all. A layer of soil covered with some dead leaves, twigs, and bark is great, but isopods will be comfortable with some paper towels or newspaper laid on the soil. They do like to have some structure to crawl under.
Food and water. The most important thing to remember is that the soil must be kept moist at all times—not wet, but moist—so that the isopods don’t dry out. A chunk of raw potato in the container with the isopods serves as a source of both food and moisture. Otherwise they will eat the decomposing leaves and twigs or the paper towels and newspaper.
Ecology
Woodlice need moisture because they breathe through gills, called pseudo trachea, and so are usually found in damp, dark places, such as under rocks and logs. They are usually nocturnal and are detritivores, feeding mostly on dead plant matter. Woodlice then recycle the nutrients back into the soil. In artificial environments such as greenhouses where it can be very moist, woodlice may become abundant and damage young plants, such as ferns.
The woodlouse has a shell-like exoskeleton, which it must progressively shed as it grows. The moult takes place in two stages; the back half is lost first, followed two or three days later by the front. This method of moulting is different from that of most arthropods, who shed their cuticle in a single process.
A female woodlouse will keep fertilized eggs in a patch on the underside of her body until they hatch into small, pink offspring. The mother then appears to "give birth" to her offspring.
Some species of woodlice are able to roll into a ball-like form when threatened by predators, leaving only their armoured back exposed. This ability, or dominant behavior, explains many of the woodlouse's common names.
Metabolic rate is temperature dependent in woodlice. In contrast to mammals and birds, invertebrates are not "self heating": the external environmental temperature relates directly to their rate of respiration.
They are not generally regarded as a serious household pest as they do not spread disease and do not damage wood or structures; however, their presence can indicate dampness problems.
Habitat and Distribution:
Pill bugs are common invertebrates that are found in many biomes around the world, including temperate forests, rainforests, and grasslands. They prefer moist areas, often living in soil and under decaying leaves, rocks, and dead logs.
Life Cycle:
A pill bug begins its life as a tiny egg. The young pill bug looks almost like a miniature adult. As it grows, it molts (sheds its old, outgrown exoskeleton) 4 to 5 times.
Anatomy:
Pill bugs are covered by a hard exoskeleton (also called the cuticle) made from chitin. They have three basic body parts, the head (which is fused to the first segment of the thorax), the thorax (the 7 segments of the thorax that are not fused to the head are called the pereon), and the abdomen (which is also called the pleon). Pill bugs have 7 pairs of jointed legs and 2 pairs of antennae (but one pair is barely visible). The antennae, mouth and eyes are located on the head. A pair of abdominal uropods are at the posterior end of the pill bug, but only the terminal exopods are visible from the top of the pill bug. Pill bugs are less than an inch long.
Diet: Pill bugs eat decaying plants and animals and some living plants.
Predators: Pill bugs are eaten by many animals. Their main protection is rolling into an armored ball.
Classification: Kingdom Animalia (animals), Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, Order Isopoda (isopods), Family Armadillidiidae, Genus Armadillidium, Oniscus, etc. Many species, including A. vulgare (the common pillbug).
