arthropods and mollusks bio quiz

most successful phylum on the planet

arthropoda

segmented bodies, tough exoskeleton, jointed appendages

body plan of arthropods

arthropods phylum name

arthropodan

molting that occurs in young animals, necessary for a crustacean to increase in size (exoskeleton does not grow) underlying epidermis secretes cuticle

ecdysis

subphylum of anthropods

* Ancient group
* No mandibles or antennae
* 2 tagma and six pairs of cephaloothroracic appendages
* 1 pair of chelicerae (define subphylum)
* 1 pair of pedipalps
* 4 pairs of walking legs

chelicerta

body plan of chelicerta

spiders, scorpions, ticks, mites, harvestmen are all part of what class

Class Arachnida

body plan of a arachnida (spider)

what order is all predaceous, have chelicerae that function as fangs, cephalorthorax and abdomen joined by thin pedicel and use web spinning to trap prey

order araneae

body plan of an araneae

all predaceous, pedipalps tp capture prey, chelicerae to rip apart prey, well developed young with maternal care

scorpions

scorpion body planShort cephalothorax (has appendages), abdomen (pre-abdomen and post-abdomen with stinging apparatus)

scorpion body plan

ticks and mites are part of what order

order acari

has cephalothorax and abdomen completely fused, mouth parts on capitulum, some are free living while others are not, transmit diseases and cause economic harm

order acari

what class are centipedes apart of

class chilopod

what class are predators, each segment contains one pair of legs, dorsoventrally flattened, maxillipeds on first segment are modified to venom claws, pairs of eyes consist of group of ocelli

class chilopods

what class are millipedes apart of

class diplopoda

Cylindrical bodies, 4 thoracic segments 1 pair of legs, Abdominal segments 2 pairs of legs

class diplopoda (millipedes) body plan

what subphylum has the general nature of a crustacean and includes lobsters, crayfish, shrimp, crabs, water fleas, copepods, and barnacles

subphylum crustacea

what is the distinguishing characteristic of crustaceans

two pairs of antennae

* Head also has a pair of mandibles and 3 pairs of maxillae
* One pair of appendages on each of the additional segments
* Some segments may lack appendages
* All appendages except perhaps first antennae are biramous
* Primitive crustaceans may have up to 60 segments: derived crustaceans have fewer
* Tagmata are usually head, thorax, and abdomen
* In most one or more thoracic segments are fused with the head as a cephalothorax
* Dorsal covering is the carapace
* May cover most of body or just cephalothorax

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body plan of subphylum crustacea

* Swimmerets or abdominal appendages retain biramous conditions
* Have evolved a wide variety of walking legs, mouthparts, swimmerets etc.. Form modification of the basic biramous appendage, some have lost 1 branch and are uniramous
* The first pair of walking legs is a cheliped with strong claw or chela for defense
* 1st pair of swimmerets in male called gonopods used in copulation
* Telson and uropod are last pair of appendages used for backwards movements and protection for eggs or young on swimmerets

appendages of crustacea

* Many forms can shift from one type of feeding to another, but they all use the same fundamental mouthparts
* Hold and crush food, mandibles and maxillae shred food and place it I mouth, cheliped serves in food capture
* Suspension feeders generate water currents in order to feed
* Predators consume larvae, worms, crustaceans, snails and fishes
* Predators consume larvae, worms, crustaceans, snails and fishes
* Scavengers eat dead animal and plant matter

feeding habits in crustacea

* The gills of crustaceans vary in shape
* Smaller crustaceans breathe through their general body surface
* Larger crustaceans use featherlike gills for gas exchange

respiratory system in crustacea

* Antennal or maxillary glands
* Waste products are mostly ammonia with some urea and uric acid
* Some wastes diffuse though gills as well as antennal gland
* paired glands located in the head

excretory and osmoregulatory organs in crustacea

what circulatory system Depends less on heartbeats and more on movement of organs and limbs to circulate blood

found in crustacea

Hemocyanin and/or hemoglobin are respiratory pigments

open circulatory system

what class is Most numerous and diverse group, has 3 pairs of legs and 2 pairs of wings on thoracic segments, has a Wide variety of habitats but few are marine, has Success due to cuticular exoskeleton and ability to fly

class insect

* Determined by mouthparts- chewing or sucking
* Phytophagous
* Plant juices
* Saprophagous
* Dead animals
* Parasites
* Host survives
* Parasitoids
* Host dies

feeding in insects

* Tubular heart
* Hemolymph- distributes hormones and nutrients

circulation in insects

* Tracheal system directly to cells
* Uses concentration gradient
* Spiracles- tracheae (cuticle) - no tracheoles (no cuticle)

respiratory in insects

* Sight
* Compound eye: composed by ommatidia
* Ocelli

sensory organ in insects

* Separate sexes
* Internal fertilization
* Various fertilization
* Various courtship behavior
* Usually lay legs
* Often specific habitats

reproduction in insects

* Holometabolous
* Complete metamorphosis
* 88% of insects
* Egg- larva- pupa(chrysalis) - adult
* Hemimetabolous
* Incomplete metamorphosis
* Egg-nymph- adult
* Nymphs often different habitat than adult

metamorphous and growth in insects

* Subject of many studies
* Can have complex and highly structured social groups
* Others temporary and uncoordinated

social behavior in insects

* Produce
* Pollination of crops
* Honey and beeswax
* Silk
* Predators on destructive insects
* Clean up of dead material
* Destroy plants causing economic losses
* Carriers of diseases
* Blood-sucking or biting species
* Destruction of property

insects and human welfare

what phylum evolved in the ocean and most groups have remained there

phylum Mollusca

what mollusk is known as an invasive pest

overtakes habitat and doesn’t let anything grow

zebra mussels (dreissena polymorpha)

* Mollusks are bilaterally symmetrical
* Characterized by a reduced coelom surrounding the heart and excretory organs
* The digestive, excretory and reproductive organs are contracted in a visceral mass
* Mollusks may have a differentiated head at the anterior end of the body
* Mantle= a thick epidermis that covers the dorsal side of the body
* Forms a cavity which houses the respiratory organs (gills) and the openings of excretory, reproductive and digestive organs
* The muscular foot of a mollusk is adapted for locomotion, attachment, food capture
* Or a combination of all

mollusk body plan

a special excretory structures that remove nitrogenous wastes in mollusks

nephridia

a cilia lined opening in nephridia

nephrostomies

what is the only mollusk that doesn’t have an open circulatory system

cephalopods

* Most mollusks have distinct male and female individuals
* Most engage in externa; fertilization
* Trochophores: free-swimming larval stage
* Only in bivalves and snails

mollusk reproduction

what are the four classes of mollusks

1. Polyplacophora
2. Gastropod
3. Bivalvia
4. Cephalopoda

which mollusk class is

* Marine mollusks that have oval bodies with eight overlapping dorsal calcareous plates
* Body is not segmented under the plates
* Most chitons are grazing herbivores



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class polypacophora (chitons)

which mollusk class is



* A primary Marine group
* Heads typically have pairs of tentacles with eyes at the ends
* During embryological development, gastropods undergo
* Torsion- mantle cavity and anus are moved from the posterior to the front
* Coiling- spiral winding of the shell

class gastropod (snails and slugs)

which mollusk class is



* Includes clams, scallops, mussels, oysters and others
* Have two lateral (right and left) shells (valves) hinged together dorsally
* Most are sessile filter-feeders
* Water circulation is mediated by siphons and rhythmic beating of cilia on gills

class bivalvia (bivalves)

which mollusk class is

* Active marine predator
* Foot has evolved into series of arms equipped with suction cups
* Squids have 10, octopuses have 8, and nautiluses have 80-90
* Have highly developed nervous systems
* Exhibit complex patterns of behavior and a high level of intelligence

class Cephalopoda