HO# _____
Arthropods Student Packet
Part 1: Arthropod Predictions
Arthropod Investigations
Investigating Insect Molting
Part 2:
Centipedes vs. Millipedes
How Do They Get Food?
Insect Body Structure
Complete vs. Gradual Metamorphosis
Name: _____________________________________________
Period: _________
Arthropod Predictions
1. Make a Prediction:
Below is a list of characteristics that may or may not be characteristics of arthropods.
Circle “yes” for each characteristic of an arthropod that you believe is true, otherwise
circle “no”. If you are unsure of an answer, take your best guess. You will have ten minutes
to complete “Make a Prediction” and “Choices.”
Characteristic
1.
An arachnid has a pair of antennae
Yes
No
2.
Insects have three body sections
Yes
No
3.
All arthropods have an internal skeleton
Yes
No
4.
Insects go through complete metamorphosis
Yes
No
5.
A lobster is a crustacean
Yes
No
6.
All arthropods have the same number of legs
Yes
No
7.
Millipedes are venomous predators
Yes
No
8.
Scorpions are insects
Yes
No
9.
Insects are the only invertebrates that can fly
Yes
No
10. The pupa stage occurs during complete metamorphosis
Yes
No
11. Spiders can inject venom into their prey
Yes
No
12. Arthropods shed their exoskeletons by molting
Yes
No
13. The bodies of all arthropods are segmented
Yes
No
14. Centipedes have two legs attached to each body segment
Yes
No
15. Arthropods are made up of five classes
Yes
No
2. Choices: In pairs, discuss your choices. Choose at least two of the characteristics above
and, using the lines below, describe your reasoning for each choice.
Characteristic # ______
Reasoning: ___________________________________________________________________________
_______________________________________________________________________________________
_______________________________________________________________________________________
Characteristic # ______
Reasoning: ___________________________________________________________________________
_______________________________________________________________________________________
_______________________________________________________________________________________
**As you complete this packet, you may correct any incorrect answers above, but please
use RED pen/pencil provided in the front of the class. DO NOT erase or cross out any
original answers.
Arthropod Investigation
3. Using text book pages 133 -145, complete the following information.
Define: Arthropod ________________________________________________________________________
__________________________________________________________________________________________
General Arthropod Notes:
 Advanced muscle structure and a well-developed
nervous system (brain and 2 nerve cords)
 Largest phylum- over 1,000,000 species
 Must MOLT because exoskeleton does not grow
with the animals
 Molt: to shed outer layer so a new one can grow
 Two body openings: mouth and anus
 Open Circulatory system- blood is not always
inside blood vessels; the blood sloshes over organs
and moves freely returning eventually to the heart
Characteristics of ALL Arthropods
1. __________________________
2. ___________________________
3. ___________________________
4. ___________________________
5 Arthropod Classes
Complete the following chart using your text book.
# of body
sections
Antennae?
# of
legs
Centipedes
Millipedes
Insects
Arachnids
Crustaceans
Total: ____
Pairs: ____
Total: ____
Pairs: ____
Total: ____
Pairs: ____
Total: ____
Pairs: ____
Total: ____
Pairs: ____
Yes or No
If yes, # ____
Yes or No
If yes, # ____
Yes or No
If yes, # ____
Yes or No
If yes, # ____
Yes or No
If yes, # ____
Investigating Insect Molting
Directions: Read the article below and then draw a picture/diagram showing your
prediction of how an insect molts.
Source: http://www.insectidentification.org/process-of-molting.asp
Molting is the process by which insects grow. Generally
accomplished through the early years of the insect's existence, molting
allows the body of the insect to expand under controlled and
protected conditions. In comparison, our (human) bodies expand with
the growing of our bones and muscles as we age. Insects, on the other hand, utilize what is
called an exoskeleton. This exoskeleton is basically their underlying bone structure that is
located on the outside of their bodies with corresponding organs and muscles located
underneath this hard shell. So in order for the insect to grow - i.e. increase in size - the insect
must shed its current skin in favor of the new skin underneath. This process is known in the
insect world as molting. As the process of molting occurs, a soft, expandable exoskeleton
begins to grow. The new exoskeleton will eventually harden and retain the original coloring
of the insect as it matures and is exposed to the elements and everyday wear-and-tear.
Depending on the species, molting can actually occur about 5 to 60 times in the life
span of an insect and is generally regarded as one of the most vulnerable processes that an
insect can go through. Yet this process is naturally required by insects to continue to grow
into a full adult stage. Not surprisingly, molting is not limited to insect species alone as even
spiders and snakes undergo the procedure as needed.
4. Based on what you learned in the article, draw a picture/diagram in the box below
showing your prediction of how an insect molts.
5. Why is it important for an arthropod to molt?
____________________________________________________
____________________________________________________
____________________________________________________
____________________________________________________
6. Using a dictionary, or context clues from the above
passage, define the word “vulnerable,” and explain
why an insect is highly vulnerable during the process
of molting. ________________________________________
___________________________________________________
___________________________________________________
___________________________________________________
7. After you have completed your drawing, go to this website:
http://www.youtube.com/watch?v=2A1i10ZIB-w
Now, update your initial picture/diagram (above) with any additional details. Be sure to
label your drawing.
Part 2
Centipedes vs. Millipedes
Directions: Read textbook p. 140 and complete the chart below.
CENTIPEDES
MILLIPEDES
How are they similar?
Differences:
Draw # of legs per segment
Differences:
How and what do they eat?
Directions:
get food.
Using textbook pages 136 - 143, describe in detail how the following arthropods
How Do They Get Food?
Crustaceans
Arachnids
Insects
Spiders
Ticks
Scorpions
Insect Body Structure
A. Read textbook p. 142, label the parts & body segments of an insect, and answer
the questions below:
B
Label the body parts:
D
A. ________________________
C
E
B. ________________________
C. ________________________
A
..
D. ________________________
..
E. ________________________
Label the body sections:
F. ________________________
F
G
H
G. ________________________
H. ________________________
8. How do the functions of the simple eye and compound eye differ? _____________________
______________________________________________________________________________________
______________________________________________________________________________________
______________________________________________________________________________________
9. Explain the process of how an insect obtains oxygen. __________________________________
______________________________________________________________________________________
______________________________________________________________________________________
______________________________________________________________________________________
Complete vs. Gradual Metamorphosis
Directions: Read textbook pp. 143 – 145. In the diagrams below, label each stage of
Complete and Gradual Metamorphosis, and describe what happens during each stage.
Name ________________________________
Period _____
Arthropod Closure
1. Closure:
Below is a list of characteristics that may or may not be characteristics of arthropods.
Circle “yes” for each characteristic of an arthropod that you believe is true, otherwise
circle “no”. If you are unsure of an answer, take your best guess. You will have ten minutes
to complete “Make a Prediction” and “Choices.”
Characteristic
16. An arachnid has a pair of antennae
Yes
No
17. Insects have three body sections
Yes
No
18. All arthropods have an internal skeleton
Yes
No
19. Insects go through complete metamorphosis
Yes
No
20. A lobster is a crustacean
Yes
No
21. All arthropods have the same number of legs
Yes
No
22. Millipedes are venomous predators
Yes
No
23. Scorpions are insects
Yes
No
24. Insects are the only invertebrates that can fly
Yes
No
25. The pupa stage occurs during complete metamorphosis
Yes
No
26. Spiders can inject venom into their prey
Yes
No
27. Arthropods shed their exoskeletons by molting
Yes
No
28. The bodies of all arthropods are segmented
Yes
No
29. Centipedes have two legs attached to each body segment
Yes
No
30. Arthropods are made up of five classes
Yes
No
3. Choices: In pairs, discuss your choices. Choose at least two of the characteristics above
and, using the lines below, describe your reasoning for each choice.
Characteristic # ______
Reasoning: ___________________________________________________________________________
_______________________________________________________________________________________
_______________________________________________________________________________________
Characteristic # ______
Reasoning: ___________________________________________________________________________
_______________________________________________________________________________________
_______________________________________________________________________________________