Ecdysozoans & Molting
Ecdysozoans grow by shedding this.
Cuticle or exoskeleton
What is the common name for nematodes?
Roundworms
What is the common name for tardigrades?
Water bears
What is the common name for Onychophora?
Velvet worms
Arthropod segmentation is organized into regions called ___.
Tagmata
How do ecdysozoans grow compared to lophotrochozoans?
Intermittently (in stages, not continuously)
What type of body cavity do nematodes have?
Pseudocoelom
What type of appendages do tardigrades have?
Unjointed lobopodal appendages
What type of skeleton do they have?
Hydrostatic skeleton
The exoskeleton is made of this polysaccharide.
Chitin
During molting, why are ecdysozoans vulnerable?
Soft body is exposed
How do nematodes perform gas exchange?
Diffusion across body surface
Name the process that allows tardigrades to stop metabolism.
Cryptobiosis
This is the only animal phylum restricted entirely to terrestrial habitats.
Onychophora
In insects, name the three tagmata.
Head, thorax, abdomen
After molting, what inflates the body before the new cuticle hardens?
Fluid expands the body
This nematode was the first multicellular organism to have its genome sequenced.
C. elegans
Tardigrades lack specialized ___ organs.
Respiratory
Onychophorans have lobopodal appendages with what feature?
A pair of claws
This external structure contributes to arthropod success.
Exoskeleton
Despite being protostomes, ecdysozoans do not show this cleavage pattern.
Spiral cleavage
Nematodes make up what percentage of all terrestrial animals?
80%
True or False: Tardigrades are extremophiles.
False (they survive extremes, but do not prefer them)
Onychophorans are unusual because some species show this behavior.
Social behavior
Estimated number of undescribed arthropod species.
9 million