Download ANswer Key Arthropods

Name: _____________________________________
1.
Arthropods are characterized by their ______segmented_________________ body. Also their
body segments bear jointed extensions called ______appendages_________________.
2.
Another distinguishing feature of arthropods is their
_______exoskeleton___________________. It provides protection and support. It is
composed of _____3_____ layers . Describe the layers and of what they are composed.
Waxy outer layer- water repeling and prevents dessication
Middle layer- chitin and protein and sometimes, calcium carbonate- strength
Inner layer- protein and chitin- flexibility; anchoring of muscles
3.
Arthropods exhibit a high degree of cephalization. Most arthropods have
_____compound____ eyes. Can you think of how this can be an advantage?
Multifaceted- improves detail, light detectors
4.
Arthropods have an _____open___ circulatory system. How is this system different from a
closed system?
Open: heart pumps blood to some vessels to open cavities where tissues are bathed in hemolymphcollected and circulated back to heart
Closed: heart- to vessels- back to heart
5.
Describe the molting process.
Shedding of exoskeleton and making a new one
6.
Arthropods are usually divided into ____5___ subphyla. Which subphyla is extinct? Trilobites
7.
Indentify the difference between chelicerae and mandibles.
Chelicerae- Pincers
Mandibles- jaws
8.
Please list 5 examples of animals for both divisions (having mandibles and having chelicerae).
9.
The diversity of crustaceans is immense. Describe the few things that all crustaceans have in
common.
Two pairs of antennae; most have mandibles
10. Describe the larval stage that all have in common. What is it called?
Nauplius- free swimming larval stage; three pairs of appendages and central eye
11. Please give examples of crustaceans that live on the land and live in the water.
Isopods, copepods
12. Why are copepods important? Can you think of another organism that depends upon them
for survival?
Source of plankton; Blue Whale
13. Isopods (a terrestrial crustacean) live in moist environments. How is their exoskeleton
adapted or lacking in adaptations for this environment?
Lacks waxy coating; needs to live in moist environment so as not to dry out
14. Please observe the remnants of the lobster on display. Can you compare the lobster parts
with the crayfish, a freshwater crustacean? Can you identify the parts.
a. Cheliped; cephalothorax; abdomen; uropod; telson
15. The subphylum Chelicerata include spiders, ticks and mites. What characteristics do they
have?
Lack of antennae; six pairs of appendages; chelicerae; pedipalps; four pairs of walking legs
16. Can you compare the respiratory organs responsible for gas exchange (intake oxygen and
discharge carbon dioxide ) with crayfish, spiders and grasshoppers?
a. Crayfish- gills; spiders- book lungs; grasshoppers- tracheae
17. What are pedipalps?
a. Aid in holding food and chewing
18.
What are spinnerets? In what animal are these found?
a. Organs that aid in making silk; found in spiders
19. Compare the excretory organs of crayfish and spiders.
Crayfish- green glands; Spiders- malpighian tubules
20. Name the two venomous spiders in the United States. Can you draw them?
a. Black Widow and Brown Recluse