zoology exam 4

what is the difference between a protostome and a deuterostome?

protostomes have a cuticle and deuterstomes do not share the same body plan

what is a lophotrochozoan and to which group above do they belong?

protostome animals characterized by either a ciliated feeding larval stage or a crown of tentacles. They belong to clade bilateria

what is a primary trait of ecdysozoans?

the molting of a cuticle as they grow

which phyla of ecdysozoans has the greatest impact on humans and why?

arthropoda are more impactful due to their sheer diversity, dominance in nearly every ecosystem, and their multifaceted, direct influence on human agriculture, health, and daily

name and describe four nematode parasites of humans. what is the nematode (common name is fine), what does it cause (symptoms), how is it contracted?

Ascaris lumbricoides causes abdominal pain, nausea, and vomiting, it is contracted from food contamination.

Hookworm causes chronic intestinal blood loss, severe anemia, weakness, and dizziness it is contracted from soil

Pinworm causes severe itchiness it is contracted through the fecal-oral route

Filarial Worm causes severe edema and thickning of the skin. it is contracted by mosquito bites.

what three phyla are in clade Paranthropoda?

Anthropoda, Onychopora, and Tardigrada

describe phylum Onychophora

velvet worms found in damp, dark, and tropical forest floors they have a soft, segmented, velvet textured cuticle, paired unnjointed stub feet with claws, and a predatory lifestyle using glue shooting oral glands to capture prey.

describe phylum Tradigrada

water bears or moss piglets found in aquatic films on mosses, litchin, soil , and marine environments they have a tubular body with four pairs of clawed legs and a chitinous cuticle that requires nothing.

why are arthropods so diverse and abundant?

because of their versatile chitinous exoskeleton, jointed appendages, small size, metamorphisis, and high reproductive rate

what are the traits of subphylum chelicarata and what are the two classes in this group?

their traits include two part body, six pairs of appendages, pincer like chelicerae, pedipalps, four pairs of walking legs, and no antennae. the classes in this group are Aracnida and Merostomata

why aren’t horseshoe crabs considered crustaceans?

because they are phylogenetically classified as chelicerates

class arachnida is highly diverse. what are four orders within the class?

Araneae two part body and most produce silk. They have fangs used to inject venom into prey. They have venom they use it to subdue prey. They are not parasites they are free living predators. example: black widow.

Scorpiones distinct segemented tail with a terminal stinger and large pincer like pedipalps. They have small pincers used to shred food, not for venom. They have venom is delivered via the stinger on the tail. They are not parasites they are free living terrestrial predators. example: emperor scorpion.

Opiliones body appears as a single oval unit legs are often extremely long and thin. They have simple pincers used for scavenging or capturing small insects. They do not possess vennom glands. They are not parasites most are scavengers or predators. example: daddy longlegs.

Acari usually tiny or microscopic cepholothorax and abdomen are broadly fused. They are variable and can be piercing stylets or barbed anchors for feeding. Them having venom differs ticks use toxins to aid feeding most mites do not. Many have parasites on plants or animals. example: deer tick

which order of arachnids exhibits complex courtship rituals?

the aranae are most known for their highly complex courtship rituals

what unifies subphylum Myriapoda? what are the two classes and how are they distinct?

They have segemented bodies a head followed by a long, modular trunk with numerous leg bearing segments, one antennae, simple eyes rather than complex compound eyes, and a tracheal system. the two classes are chilopoda and diplopoda

Chilopoda has one pair of legs per body segment, dorsoventrally flattened, are carnivorous predators that hunt insects and small animals, have venom, fast and agile runners, and primarily use speed to flee or their venomous bite to fight back

Diplopoda has two pairs of legs per segment, cylindrical or rounded, detritovors that feed on decaying plant matter and leaf litter, do not have venom they often secrete toxic or foul smelling fluids for defense, slow and steady movers with a wave like leg motion, and typically curl into a spiral to protect their soft underside

what unifies subphylum crustacea? what are the two classes and how are they distinct?

subphylum is unified by a unique combination of physical traits and developmental stages.the two classes are malacostraca and maxillopoda

malacostraca consists of crabs, lobsters, shrimp, krill, and woodlice, have a fixed body plan: 5 head segements, 8 thoratic segments, and 6 abdominal segments, they possess pleopods on the abdomen, they are typically larger and more complex, and usually have stalked compound eyes.

maxillopoda consists of barnacles, copepods, and fish lice, have short bodies with no more than 11 segments and often a reduced abdomen, abdomen usually lacks appendages, tiny or microscopic, and often have a single simple eye.

some crustaceans are filter feeders, but others are predators. what is an example of an organism for each of these feeding habits and how do they accomplish their goal ?

the goose barnacle: they are essentially “shrimp like” animals that live upside down in a limestone house. they use feathery thoracic legs called cirri it opens it shell and kicks its cirri into the water column thy act as a microscopic net trapping their prey.

the peacock mantle shrimp: spearers lunge with lightning speed to implate soft bodied fish. smashers then use a spring mechanism to strike instantly shattering the shells of crabs and snails.

some crustaceans are parasites. what are two examples of parasitic crustaceans and what is their method of parasitism?

tongue-eating louse: this is a specialized isopod, it enters the fish through its gills and attatchs itself to the base of the fish’s tongue. it grips the tongue with its legs and sucks blood until tongue tissue withers away and falls off.

sacculina barnacle: this barnacle targets crabs, a female larva finds a chink in a crab’s armor and injects a tiny clump of cells into its body. the cells grow into a rootlike network that spreads throughout the crab’s entire body, absorbing nutrients directly from the blood.

class malacostraca is the largest and most diverse of crustaceans. what unifies this class? what are the three orders and how are they distinct?

class malacostraca is unified by a strict, highly organized body plan. nearly all members share a specific 20 segment structure.

head: 5 segments always bearing a pair of legs

thorax: 8 segments each typically bearing a pair of legs

abdomen: 6 segments featuring swimming legs and a tall fan

stalked compound eyes: most species have eyes on moveable stalks, providing a wide field of vision

the three major orders:

decapoda consists of crabs, lobsters, and shrimp, they have five pairs of thoracic walking legs, well developed carapace covering the head and thorax; typically has stalked eyes

isopoda consists of woodlice, and sea slaters, they are pancake flat from top to bottom, and no carapace; eyes are sessile includes many teresttrial species.

amphipoda consists of scuds and sandhoppers, they are flattened from side to side, no carapace; possesses

among decopods, what differenciates infraorder brachyura from infraorder anomura?

the number of

which class of arthropods is the largest and most diverse of any organism on earth?

class insecta

what are the body segments of insects and where do legs and wings attatch?

the segments of an insect are head, thorax, and abdomen. the legs attatch to the thorax on an insect, the wings are attatched to the thorax on an insect,

what are the different feeding methods of insects? provide an example for each, how are the mouthparts different?

the major feeding methods of insects are chewing, piercing/sucking, siphoning, and sponging. the mouthparts differ becuase the mandible is hard tooth like jaws that move horizontally to cut and crush, the stylet is a needle like bundle formed from several mouthparts usually in a protective sheath, the proboscis is a long, coiled tube that acts like a straw, it uncoils using fluid pressure to feed, and the labellum is a fleshy, spongelike pad at the tip of the proboscis

what is the significance of hemolymph and a tracheal system?

they duplicate the delivery of nurtients to the delivery of the oxygen

what are four sense organs foun in insects?

compound eyes, antennae, typanal organs, and johnston’s organs

what is the difference between holometabolous and hemimetabolous metamorphosis? provide an example for each.

holometabolous involves a total recognition of the body. young larva usually look, eat, and live completely different than the adults. example: monarch butterfly

hemimetabolous is a more gradual transition the young look like miniature wingless versions of the adults. example: grasshopper

what are methods of communication among insects that exhibit social behvior? provide an example for each.

the methods of communication are chemical communication example: ants, tactile and vibratory communication example: honey bees, acoustic communication example: soldier termites, and trophallaxis example:wasps.

what are two benefits and two harmful interactions between insects and humans?

two benefits between insects and humans are pollination because one third of human food supply depends on insect pollination, the pollen enables the production of fruit, vegetables, and nuts. decomposition and soil health because insects break down the dead organic matter in soil and it produces vital nutirents into the soil, and prevents the buildup of waste in the environment

two harmful interactions between insects and humans are disease vectors because insects are responsible for spreading some of the most deadliest diseases, this interaction causes millions of human deaths and illnesses. agricultural pests because insects can decimate entire crops in one day leading to million dollar losses and producing famine

what are three phyla in deuterostomes?

chordata, echinodermata, and hemichordata

what unifies all echinoderms ; what are the four primary classes and how are they distinct?

it is a group of exclusively marine animals, they are unified by several unique biological “blue prints”

asteriodea consists of sea stars, have thick arms that blend into a central disc, move slowly using tube feet.

ophiuroidea: consists of brittle stars, distinct central disk with long flexible arms, move quickly by wiggling their arms.

echinoidea: consists of sea urchins and sand dollars, no arms and body is a shell, uses moveable spines and tube feet,

holothuroidea consists of sea cucumbers, have elongated bodies with leathery skin and no spines, they move using rows of tube feet or body contractions

in detail describe the water vascular system of sea stars and how it is used for locomotion

it is a unique hydraulic system that functions using a combination of circulatory system and a mechanical engine. it allows the sea stars to move and grip surfaces and also evenly prout open prey by using water pressure rather than trsditional muscle to bone leverage. it aids in locomotion through the cordinated action of thousands of tube feet. tube feet consists of two main parts the ampulla and the podium

in detail describe feeding and digestion among sea stars

sea stars often perform extra oral digestion meaning they begin breaking down their food outside their body. this allows them to consume prey that is much larger than their mouth

what is the difference between a sea star and brittle star?

how their arms connect to their central body and how they crawl across the seafloor

what is the difference between a “regular” urchin and an “irregular” urchin, provide an example for each

the difference is their symmetry and how they move through their environment

an example of a “regular” urchin is a purple sea urchin

an example of a “irregular” urchin is a sand dollar

what is the feeding structure of echinoids?

a complex five toothed mechanism called aristotle’s lantern

why are sea cucumbers able to jettison their digestive tract, respiratory tree, and gonads?

they do it through a process called eviseration, it allows them to sacrifice expendable parts to ensure the survival of the whole organism

why arent hemichordates considered true chordates?

they lack the big four characteristics that define a true chordate

compare and contrast class enterpneusta and class pterobranhia.

enterpneusta live solitary, burrow in sand or mud on the seafloor, are deposit feeders, use a large muscular proboscis to collect food, are generally larger, and have neumerous pairs of gills used for respiration and filter feeding.

pterobranhia mostly colonial, are sessile, are filter feeders, they possess branching, ciliated tentacles on the collar, are minute, the gills are reduced to on pair or are absent