zoology arthropods and mollusks Flashcards
where are arthropods found
any environment
what is the difference between an open an closed circulatory system?
closed systems keep blood in veins, open systems pump blood into body
What kind of circulatory system do mollusks have?
open
what kind of circulatory system do arthropods have?
open
what is the name of the body cavities where blood collects in open circulatory systems?
hemocoel
what is the difference between biramous appendages and uniramous appendages?
biramous appendages are branched, uniramous appendages aren’t
what is ecdysis?
molting
why do arthropods molt?
in order to grow
what part of the mollusk secretes the shell? what is it made of?
secreted by mantle, made of CaCO3
general body plan of hexapods
head, thorax, and abdomen
general body plan of chelicerates?
cephalothorax and abdomen
general body plan of myriapods
head and trunk
grasshopper vs. crayfish: which has more body segments? which has more walking legs?
the grasshopper has 3 body segments, crayfish have 2 segments. Grasshoppers have 3 pairs of legs, crayfish have 5 legs (1 of which are claws)
which arthropod most likely first lived on land?
millipedes
What characteristics of arthropods allowed them to transition from aquatic to terrestrial life?
book lungs; first absorbed oxygen as a gas, not from water
exoskeleton; keeps shape outside of water, keeps animal dry
what are chelicerae? how are they used by chelicerates?
they are pointed mouthpieces, used to catch prey
where are the legs and wings attached to the body of a typical hexapod?
thorax
etymology of mollusca
soft body
etymology of arthropoda
jointed foot
compare number of legs on millipedes and centipedes
millipedes have 2 appendages per segment, centipedes have 1 appendage per segment
what are exoskeletons made of?
chitin
arthropod reproduction
sexual, internal
what is the largest and second largest animal phylum?
arthropoda, then mollusca
what is a carapace?
hard plate covering the thorax and head (ex. turtle shell)
respiratory structures of hexapods
tracheae
respiratory structures of crustaceans
gills
respiratory structures of arachnids
lungs and tracheae
what do most millipedes eat?
rotting wood or fruit, other plants
what do most centipedes eat?
bugs
how do major mollusk groups move?
with their foot (jets with cephalopods)
how do major mollusk groups feed?
with radula (mouth for cephalopods)
common chelicerates
spiders, scorpions, horseshoe crab
common crustaceans
lobster, crab, krill
common hexapods
ants, beetle, moth
common myriapods
centipedes, millipedes
living fossil
horseshoe crab
largest arthropod
hexapod
how does the cephalopod’s foot compare to other mollusks?
they turned into arms
what are three body parts common across all mollusks
head, foot, visceral mass
common bivalves
oysters, clams, mussels
common cephalopods
octopus, squid, nautilidae
common gastropods
snails, slugs
characteristics shared by all arthropods
segmented body, jointed appendages, bilateral symmetry, exoskeleton
