arthropods part two Flashcards
what two classes belong tow the sub phylum hexapoda
1) entognatha
2) insecta
what is the insecta class divided into
1) apterygota
2) pterygota
give some characteristics of the class insecta belonging to the subphylum hexapoda
- abundant
- key role in diets of many animals
- role of decomposers
- vectors of diseases
how does the strengthened exoskeleton act in hexapods
- protection from predation
- increased support for terrestrial life= more gravity than in water
how have beetles forewings been modified
produced two wing cases called a elytra
what are halteres
the balancing organ of a two-winged fly, seen as either of a pair of knobbed filaments that take the place of the hindwings, vibrating during flight.
where does the flower for flight usually come from in insecta
the elastic-mechanical properties of the exoskeleton which changes shape in the thorax rather than direct flight muscles
what is a tagmata
a morphologically distinct region comprising of several adjoining segments such as the head, thorax and abomen
an insects body is organised into three tagam
how is the body divided in the subphylum cheliceriformes
dived into two tagmata
1) prosoma aka cephalothorax
2) opisthosoma aka abdomen
- no antenna
what are the two classes of cheliceriformes
1) pycnogonida (marine spiders)
2) chelicerata (all the rest)
outline the body plan of the pycnogonida
- anterior proboscis and oviger (modified legs to carry eggs)
- pedioalos =
where are pycnogonida found (sea spiders)
all marine from intertidal to deep sea
what species belong to the class chelicerata in the subphylum cheliceriformes
- horseshoe crabs
- spiders
- scorpions
- mites
what is the sub class of the class of chelicerata
merostomata = horseshoe crabs
what subclass to mites, ticks, scorpions and spiders belong to
arachnida
what is the difference between hard and soft ticks
hard ticks are heavily scleroticised and remain attached to hosts for days- weeks
soft ticks are transient and remain on host for a few hours
what order do spiders belong to
araneae in the subphylum cheliceriformes
outline the body plan of spiders
prosoma (chephilothorax) undivided and covered by a shield attached to a opisthoma by a pedicel (the thin waste like structure)
what is found in the prosoma of spiders
- chelicerae modified fangs
- eight eyes on the dorsal surface
what does the opisthoma (abdomen) have in spiders
- book lungs/ tracheae for respiration
- silk producing glands
how is a scorpions (order scorpiones) body divided
1) prosoma with a carapace sheild
2) opisthoma (abdomen) elongated
3) telson (terminal appendage)
4) pedipalps
why do scorpions glow under UV light
a result of sclerotization
what is spider silk
complex fibrous proteins produced in a liquid form which turns into an insoluble thread
outline some characteristics of the phylum tardigrada (not an arthropod)
- minute
- found in water
- thin chitnous cuticle
- feed on algal or moss cells
