Earthworm lab:
NC Standard Course of Study Objective:
4.02 Analyze the processes by which organisms representative of the following groups accomplish
essential life functions including:
•
•
Unicellular protists, annelid worms, insects, amphibians, mammals, non vascular plants,
gymnosperms and angiosperms.
Transport, excretion, respiration, regulation, nutrition, synthesis, reproduction, and growth
and development.
4.03 Assess, describe and explain adaptations affecting survival and reproductive success.
•
•
•
Structural adaptations in plants and animals (form to function).
Disease-causing viruses and microorganisms.
Co-evolution
Activity
Description of Activities and Setting
Materials and Time
I. Focus and Review
(Establish prior
knowledge)
If students have previously learned the basic
characteristics of the different invertebrate phyla,
they should be asked to determine which phylum
includes earthworms. (Annelid)
5 minutes
II. Statement (Inform
student of objectives)
In class we will be examining the anatomy and
behavior of an earthworm. We will look closely at
one interesting behavior and determine why it is
adaptive for the worm.
III. Teacher Input
(Present tasks,
information, and
guidance)
Students should be divided into groups of three or
four and given an earthworm on a damp paper
towel. The paper towel should be placed in some
kind of container so that the worms don’t get
away. For two minutes, students should observe
the worm and record its behavior, including if and
how far it moves, and any additional behaviors
that they see. This will be recorded on their lab
sheet under “Worm’s behavior without
vibrations.”
10 to 20 minutes,
depending on length
of class.
Materials: Earthworm,
plastic or cardboard
box, damp paper
towel, clock or
stopwatch, tuning fork,
ruler, lab handout
Afterward, students will watch a short video of an
earthworm dissection where the different organs
of the worm are labeled and explained. Students
can follow along and label the different parts of
the worm on their diagram. It may be necessary to
go over the anatomy of the worm as a class after
the video. At the end of the lab, they will be asked
to think about which parts of the worm’s body are
responsible for regulating, signaling, and
performing its behaviors.
Earthworm dissection video:
http://www.youtube.com/watch?v=A2BY0hRUA9E
IV. Guided Practice
(Elicit performance,
provide assessment
and feedback)
In their groups of three or four, students should
follow the directions on the handout provided
below. Remind them that they should not forget
to include a hypothesis! Students will observe how
the worm responded to vibrations at different
distances from its body, and they will measure
how far it moves. (You should remind the class
that the worm will not necessarily respond by
moving towards or away from the vibration. They
should look for any other interesting behaviors as
well.)
When every group has collected at least three to
four trials of data, the class should compile what
they have observed. One way to accomplish this
would be to have students copy their data onto a
table on the board. Students should then calculate
the average distance moved and the average time
it took the worm to respond for each of the
distances from a vibration.
Students will record the class’s data in their
second table. They should then be asked to work
with their group to interpret their results.
After finishing the experiment, you can watch a
video about “worm grunting.” A link to one video
is provided here. It is possible to lure hundreds of
earthworms out of the ground by vibrating the
30 minutes
Materials: earthworm,
container for
earthworm, damp
paper towel, tuning
fork, ruler, handout
earth.
http://www.youtube.com/watch?v=FK-Oo7NwPiQ
If there is enough time left in class, ask students to
discuss with their group why they think
earthworms have evolved this response.
Leading questions:
-What are some dangers that earthworms face?
-What animals are dangerous to a worm? Why?
-What kinds of warnings would an earthworm
receive from an approaching predator?
After students have discussed the question and
generated a few possible explanations, show them
the last video.
This video shows how worms exhibit the same
behavior when a mole approaches them
underground. Earthworms’ response to vibration
is an adaptation they evolved to escape from
worm-eating moles.
Mole explanation:
http://www.youtube.com/watch?v=IGviTYCFksE
V. Independent
Practice -- Seatwork
and Homework
(Retention and
transfer)
Students are asked to answer conclusion questions 10 minutes or the rest
that require them to connect what they have
of class.
learned of worms’ anatomy and behavior.
Handout and Key:
Laboratory: Observing Worm Responses to Vibrations
Purpose: To determine how earthworms respond to vibration.
Materials: Earthworm
Tuning Fork
Ruler
Clock or Watch with Second Hand
Damp paper towel
Procedures:
1. Obtain one worm and the necessary materials.
2. Place the worm on the damp paper towel.
3. Observe the worm for one minute. Record its distance traveled. If it does not move or
behaves in some other way, record what it does.
4. Strike the tuning fork and place the handle of the tuning fork on the table at a distance of
2.0 cm. from the anterior (front) end of the worm.
5. Determine the amount of time it takes for the earthworm to respond and how far (if at
all...) the worm moves. Record these results in the Data Table 1. (Note: If the worm does
not respond within one minute, move on to the following step.)
6. Strike the tuning fork and hold it 3.0 cm. from the anterior end of the worm.
7. Record the time it takes for the worm to respond and how far the worm moves in any
direction.
8. Repeat Steps 5-6, increasing the distance by 1.0 cm. for every trial. Stop when the worm
does not respond to the tuning fork for three trials in a row. Note: Be sure to give
adequate time for the earthworm to feel the vibrations and start to move.
9. Compile class results in Data Table 2.
10. After recording all the information in the Data Table 2, determine the minimum,
maximum, and average distance of the tuning fork for an earthworm response.
Hypothesis:
For two minutes record how often and how far it moves, and any other behaviors that you observe.
Do not touch the worm during this time.
Worm’s behavior without vibrations:
Group Data Table
Trial
Distance from
vibration
Time to response
Distance traveled
Other
Observations
1
2
3
4
5
6
7
Class Data Table
Trial
1
2
3
Distance from
vibration
Average time to
response
Average distance
traveled
Other
Observations
4
5
6
7
What trends did you notice in this data?
What conclusions can you draw?
On the diagram below, label these parts of the worm:
Anus
Crop
Intestine
Segments
Blood vessel
Esophagus
Mouth
Brain
Gizzard
Pharynx
Clitelum
Hearts
Nerve Cord
Conclusions:
1. Will one worm form two live worms if it is cut in half? Why or why not?
2. Which parts of the worm’s anatomy are responsible for perceiving and then responding to the
vibration?
3. Why is this adaptation beneficial for the worm? Explain how this behavior would evolve.
Key: 35 points total
Hypothesis: 3 points
Control Worm distance traveled and other observations:
2 points
Data Table 1
Trial
Distance from
vibration
Time to response
Distance traveled
Other
Observations
1
2
3
4
5
6
7
Data Table 2
Trial
Distance from
vibration
Average time to
response
1
2
3
4
5
6
7
10 points for completed tables (5 points each)
Average distance
traveled
Other
Observations
What trends did you notice in this data?
Answers will vary. (2 points)
What conclusions can you draw?
Answers will vary. (3 points)
On the diagram below, label these parts of the worm: 5 points
Anus
Crop
Intestine
Segments
Blood vessel
Esophagus
Mouth
Brain
Gizzard
Pharynx
Clitelum
Hearts
Nerve Cord
Conclusions:
1. Will one worm form two live worms if it is cut in half? Why or why not?
No, this is a common misconception. The worm will not have all the organs it needs.
3 points
2. Which parts of the worm’s anatomy are responsible for perceiving and then responding to the
vibration?
The nerve and brain are responsible for perceiving and responding to the vibration. The
muscles are responsible for moving the worm.
3 points
3. Why is this adaptation beneficial for the worm? Explain how this behavior would evolve.
The worm can escape predators like moles. When they sense vibrations in the soil, they know
to move to the surface. Worms whose genetics made them more likely to move to the surface
when they felt vibrations were most likely to survive and reproduce. These worms will
continue to pass on their traits.
4 points