Arthropod Cycles
Rhonda Hawley, Educator, MathScience Innovation Center
Developed with funding from the MathScience Innovation Center
Major
Understanding
Arthropods are the largest phyla in the animal kingdom and all animals go
through orderly changes in their life cycles. Arthropods are animals that are
classified with specific physical characteristics, including exoskeletons, jointed
legs, and segmented bodies. Physical adaptations allow arthropods to protect
themselves and respond to their life needs: food, water, air, and a suitable place
to live (habitat). The life processes of arthropods are affected by seasonal
changes and weather.
Grade/Subject
Grade 2; Biology & Environmental Science
Objectives
Understand that behavioral and physical adaptations allow animals to
respond to life needs.
Classify arthropods based on two or more attributes.
Investigate and understand that arthropods go through a series of
changes in their life cycles.
Understand that weather and seasonal changes affect animals and their
surroundings.
Understand that living things are part of a system interdependent with
their living and non-living surroundings.
Time
Anticipatory Set
Arthropods VENN
Arthropods Up-Close!
Mixed-Up Life Cycles
Closure
Practice
Assessments
Materials
For the class:
 Tadpole’s Promise by Jeanne Willis
 Chart of animal distribution
 5 types of arthropods in cages/containers: tarantula, mealworms,
cockroach, cricket, and ladybugs
 Spider egg sac in viewing box
 Molt of a spider
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5 min
15 min
20 min
10 min
5 min
Variable
Variable
©MathScience Innovation Center, 2009
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Scissors
Glue sticks
Posters of complete and incomplete life cycles
Stages of life cycle cards
Metamorphosis Cycle Cloth
For each group of students:
 1 copy of Mixed-Up Life Cycles handout
State and National
Correlations
Virginia Standards of Learning: 2010 Science (2.1, 2.4, 2.5, 2.7, 3.4)
National Science Education Standards: Observe, predict, infer, and draw
conclusions; Life cycles; Living organisms are interdependent with their
surroundings; Investigate relationship of seasonal change and weather to the
life processes of arthropods; Behavioral and physical adaptations.
Instructional
Strategies
1. Anticipatory Set
1.1. Ask students, “What do you think is the largest group of animals in the
world?” Allow responses and record them on the board. Then show
students the chart of animal distribution and discuss. Tell students that
81% of all animals are arthropods.
1.2. Write the word “Arthropod” on the board and have students pronounce
the word. Tell students for an animal to be an arthropod it must have
three physical characteristics: 1) an exoskeleton, which is an outside
skeleton that is hard and protects the animal from the outside; 2) a
segmented body; and 3) jointed feet or legs. Allow students to give
examples of joints in their body (e.g., finger, jaw, knee, elbow, etc.).
2. Arthropod VENN
2.1. Tell students that arthropods are made up of some smaller groups of
animals, such as insects and spiders. Draw a VENN diagram on the
board to represent spiders and for the insects choose one type of insect
to focus on, butterflies. Explain how a VENN diagram works and ask
students to help you fill it in. Begin by focusing on the physical
differences and similarities; then move on the similarities of life needs
(food, water, air, shelter); focus also on habitat needs. Be sure to save a
bit more room in your VENN diagram to add more facts.
2.2. Share the life cycle of a spider by passing around the egg sac,
discussing growth via molting. Share the box of the tarantulas molt and
explain how the spider would lie down on their back and then kick off
the old skeleton and reveal the new skeleton underneath that is larger.
Explain why spiders need to take off their exoskeletons and the extreme
effort it involves. Conclude the spider life cycle by sharing that most
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©MathScience Innovation Center, 2009
spiders die at the end of 8-9 months but they leave eggs to start the life
cycle over again. (For more information about the spider life cycle,
refer to www.spiderroom.info which illustrates the cycle.)
2.3. Then ask students if they think that butterflies have the same life cycle
as a spider. At this point, students will probably shout out that the
butterfly does not have the same life cycle because it starts out as a
caterpillar and then builds a chrysalis and changes into a butterfly. Here
is the perfect place to introduce the words complete and incomplete
metamorphosis. Direct students’ attention to the Metamorphosis Cycle
Cloth (an enlarged version of the worksheet). Briefly review the
different stages and relate to the spider and butterfly from our VENN
diagram.
2.4. Reinforce the concept of complete and incomplete metamorphosis by
reading the book Tadpole’s Promise to students. Explain to students
that animals do not get to choose whether they will have complete or
incomplete metamorphosis—it is the natural manner for them to grow.
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8 legs
2 body parts
Webs
Looks like
mom & dad
Spiders
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Size
Food
Water
Shelter
Air
 Eggs
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6 legs
3 body parts
Wings
May look like
mom & dad
Butterflies
3. Arthropods Up-Close!
3.1. Now it is time to get an up-close look at some real arthropods. Divide
class into 5 groups. Introduce each animal and discuss their life needs
briefly. Give each group a different caged arthropod. Rotate the
animals from group to group every 5 minutes until all groups have
experienced all materials. Focus on the three physical characteristics of
each arthropod. Teacher should move from group to group observing
progress and answering any questions during the rotation.
3.2. Go over the rules governing arthropod observation. No opening the
cage of the tarantula. The cockroaches, crickets, ladybugs, and
mealworms’ cage tops may be opened so that students can put their
hand in to touch the animals. Be aware that all of the animals can move
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quickly. Do not allow them to fall from the table to the floor.
3.3. Discuss which of these animals can live in Virginia. The hissing
cockroach and tarantula do not naturally live in Virginia because it gets
too cold in winter for them. Can the others survive? How?
4. Mixed Up Life Cycles
4.1. Collect all animals and display them in front of the class. Then ask
which life cycle does each have—complete or incomplete?
4.2. Follow up this discussion by passing out the handout “Mixed Up Life
Cycles” where students will need to cut out the mixed up pieces of each
life cycle and put them together correctly. Before the pieces are glued
down, the teacher should check to ensure accuracy.
Practice
Student may go to http://www.SpiderRoom.info; then select Follow a Spider’s
Life Cycle; and take the Quiz to practice what we have learned today.
Closure
1. Have students assemble the two different life cycles using the handout
“Mixed Up Life Cycles.” Students may work in pairs or individually to
arrange the cycles correctly. Teacher will check each cycle before students
glue them down.
2. Ask students the following questions:
 List three special parts an animal must have to be classified as an
arthropod.
 What is an exoskeleton?
 What four things do all animals need to live?
 What do we mean when we talk about the life cycle of an animal?
 What is the difference between complete and incomplete
metamorphosis?
 Name a special adaptation that an arthropod might use to protect itself.
Extensions
1. In warm weather, go outside for an “Arthropod Hunt.” Provide students
with baby food jars or 35 mm containers with holes punched in the lids to
collect specimens. Allow students to observe the specimens using
magnifying glasses. Visit http://www.whatsthatbug.com/ and use their
archives to identify many of the arthropods that you have captured. Later in
the day, release the arthropods back into their natural habitats.
2. Check out the Spiderology Kit from the MathScience Innovation Center.
This kit offers a unit of study that covers habitats, food chains and webs,
adaptations, life cycles, and lots of hands-on amazing materials.
3. Go to http://www.spiderroom.info for a plethora of spider materials and
information. Some big topics that are covered are: the anatomy of a spider,
Arthropod Cycles
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©MathScience Innovation Center, 2009
spider life cycles, spider webs, spider survival, and many different Virginia
spider species. A great place to start is found under Spider Survival where
students can explore: Playing Defense; Hide a Spider; On the Offense; and
Survival Web Quest.
4. Have students visit the Web sites listed below to explore and research other
arthropods that were not discussed in class. Many of the Web sites listed as
resources provide detailed lesson plans which would greatly enhance
student learning.
Assessment
Sample items are provided for use in checking students’ understanding.
Paper Pencil Test: Arthropod Cycles
Paper Pencil Test Answers
Product and Rubric: Arthropod Cycles
The following table shows how the assessment items are related to specific
objectives.
Objective
PaperPencil
Test
Understand that behavioral and physical
adaptations allow animals to respond to life
needs.
1, 5, 6, 8
Classify arthropods based on two or more
attributes.
2. 9
Investigate and understand that arthropods go
through a series of changes in their life
cycles.
3
Understand that weather and seasonal
changes affect animals and their
surroundings.
4
Understand that living things are part of a
system interdependent with their living and
non-living surroundings.
7, 10
Major Understanding: Arthropods are the
largest phyla in the animal kingdom and all
animals go through orderly changes in their
life cycles. Arthropods are animals that are
classified with specific physical
characteristics including exoskeletons, jointed
Arthropod Cycles
http://mathinscience.info
Product/
Performance
Student
Project and
Rubric
©MathScience Innovation Center, 2009
legs, and segmented bodies. Physical
adaptations allow arthropods to protect
themselves and respond to their life needs:
food, water, air, and a suitable place to live
(habitat). The life processes of arthropods are
affected by seasonal changes and weather.
Teaching Tips
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Background Information
Insects undergo development known as complete or incomplete
metamorphosis. Over 80% of all insects develop through complete
metamorphosis. During this type of metamorphosis, an insect hatches from
an egg as a worm-like larva. The larva then advances to the pupa stage.
During this period, the insect is reactive. In the case of a butterfly, this
would be the cocoon state. The last stage of development is adulthood.
During incomplete metamorphosis, the egg hatches into a nymph. The
nymph looks like a small adult but may be missing some important
structures, like its wings. By the time it becomes an adult, these structures
will develop and appear. This is the type of metamorphosis a grasshopper
undergoes. Metamorphosis is important to an insect’s survival because
during this process, many of the young feed on different foods than the
adults. This allows the young to grow and develop without being in
competition for the adults’ food supply.
http://www.uen.org/utahlink/activities/view_activity.cgi?activity_id=2024
Of the animals that we have brought today the mealworm and ladybugs are
the only complete metamorphosis, and the tarantula, cockroach, and
crickets are incomplete metamorphosis.
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Purchasing arthropods is not difficult, but be aware that depending on the
time of year, some specimens may be hard to come by. Most pet stores will
sell tarantulas, mealworms, cockroaches, crickets, ladybugs and other
arthropods (i.e., hermit crabs, scorpions) that we do not use in this lesson.
A good resource for arthropods in the Richmond area is:
Fin & Feather Pet Center, Inc.
5208 Lakeside Ave.
Richmond, VA 23228
http://www.fin-feather.com
(804) 262-6681
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References
Arthropod Cycles
Set up a spider habitat in your classroom for students to get an up-close
look at spiders. Home Away From Home is a pdf file that gives you all the
directions for setting up a spider habitat in your own classroom!
Bugscope Project
The Beckman Institute’s project is an educational outreach program for K-12
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©MathScience Innovation Center, 2009
classrooms. The project provides a resource to classrooms so that they may
remotely operate a scanning electron microscope to image “bugs” at high
magnification. It also provides an excellent link to arthropods and lesson plans
by clicking “About Insects” under “Helpful Resources.”
http://bugscope.beckman.uiuc.edu
Camouflage Field Guide
Presented by Harcourt School Publishers, this is an AWESOME interactive
field guide that allows students to try and hide animals in the Arctic Meadow,
Coral Reef, Rain Forest, or African Grasslands.
http://www.harcourtschool.com/activity/camouflage/camouflage.html
Disappearing Act
Science Learning Network. This site allows you to hide shapes in patterned
backgrounds to learn about camouflage. May, 2002.
http://www.exploratorium.edu/exhibits/disappearing_act/
Exploring Hide & Seek
Dragonfly Magazine Web site. This is a GREAT site with a fun activity named
"Hide and Seek Sea." Click on the icon entitled Hide & Seek to begin.
http://www.units.muohio.edu/dragonfly/about.shtml
MathScience Innovation Center
Information on educational programs available to students, teachers and school
divisions, and procedures for registering for programs.
http://msinnovation.info
MathScience Innovation Center: On-Line Educational Programs
Learn through on-line virtual classrooms, Web-based lessons, and on-line
courses. Access proven lesson plans and instructional modules.
http://mathinscience.info
SpiderRoom.info
This site is created and operated by the MathScience Innovation Center and
offers a wide variety of activities for the teacher and students all centered on
spiders. Some big topics that are covered are: the anatomy of a spider, spider
life cycles, spider webs, spider survival, and many different spider species.
http://www.SpiderRoom.info
What’s that Bug?
Not sure what you have found creeping around in your classroom? This is the
site to help you out! First stop is their archives with lots of photos and
descriptions. But, if you can’t find it there, submit a photo of your creepy
crawly, asking what it might be and they will reply in a timely matter.
http://www.whatsthatbug.com/
Arthropod Cycles
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©MathScience Innovation Center, 2009