Ecdysozoans Flashcards
Ecdysozoans: The _______ Animals
Molting
In Ecdysozoans, A major innovation during animal evolution: development of ________
exoskeleton
An animal with an exoskeleton grows by ___________
periodically molting
The presence of an exoskeleton opened avenues for the evolution of ___________ plans
new body
Animals with Flexible Exoskeletons have Tough _________ are found in members of two phyla that live in freshwater, marine, and terrestrial environments
cuticles
What are cuticles?
exoskeleton that protects body but provides no support
Phylum ___________: Roundworms
Nematoda
Nematoda; Many are ________; most are _______ living
parasites; free
What are some examples of Nematoda?
Trichinella; Ascaris, hookworms, pinworms, Wuchereria
Phylum ___________: “jointed foot”
Arthropoda
In arthropoda, Body covering became thickened and rigid by the incorporation of layers of ______________
protein and chitin
Animals with rigid exoskeletons have appendages that can be _____________ by muscles
manipulated
The bodies of all chelicerates are divided into two major regions: ______________
cephalothorax and abdomen
Cephalothorax bears __________ of jointed legs
four pairs
In Chelicerates, the class __________ include scorpions, harvestmen, spiders, mites, and ticks
Arachnida
Crustaceans have a body divided into two regions: a __________________
cephalothorax (= head + thorax), and an abdomen
Examples of Crustaceans
shrimps, lobsters, crayfishes, crabs, sow (= pill) bugs (or roly polies), barnacles, and sand fleas
Insects have three body regions: _____________
head, thorax, and abdomen
Insects, single pair of _________ on the head
antennae
Insects, _____________ attached to the thorax
three pairs of jointed legs
Insecta, Crustacea, Arachnids, and Chelicerata are part of what phylum?
Arthropoda
What is metamorphosis?
Metamorphosis: substantial change between one developmental stage and another
Complete Metamorphosis: adult looks __________ from larva
completely different
Incomplete Metamorphosis: eggs hatch into nymphs (or instars) which look like ____________
miniature adults
What subphylum are the Centipedes and Millipedes part of?
Myriapoda
Myriapoda have many _____________ and ________ pairs of legs
segments; many
Centipedes: _____ legs per segment; _________
two; predators
Millipedes: ________ legs per segment; ________ or plant feeders
four; scavengers
Most evolution of protostomes took place in the _________
oceans
In protostomes, Early animals used fluid-filled spaces as _________ skeletons
hydrostatic
In protostomes, __________ may have led to the development of hard, external body coverings
Predation
In protostomes, Subdivision of the body cavity _____________________
increased movement control and permitted independent body part movement
