BIO 221 Exam 3 Study Guide

What is the tagmata of arachnida?

Cephalothorax (prosoma) and Abdomen (opisthosoma)

T/F: Cephalothorax with 1 pair of chelicerae and pedipalps each, 4 pairs of legs

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What is the tagmata of Scorpiones?

Cephalothorax, preabdomen, postabdomen, pedipalps large and chelate

What appendages does the cephalothorax have in Scorpiones?

chelicerae pedipalps, legs

How many segments does the Scorpiones have in the preabdomen?

seven

How many segments does the Scorpiones have in the postabdomen?

5 with stinging apparatus

What appendages is attached to the pedipalps large and chelate in Scorpiones?

4 pairs of walking legs

What tagmata does Acari have?

Idiosoma and Capitulum: chelicerae, pedipalps

What appendages is attached to capitulum in Acari?

4 pairs of legs

What are the tagmata of Myriapoda?

head and trunk with multiple segments

Where are most paired appendages in Myriapoda?

trunk segments

What are the diseases that Acari can transmit?

Ixodes transmit lyme disease (bacterium Babesia)

Dermacentor: Rocky Mountain spotted fever (bacterial infection)

What is the Hexapoda tagmata?

head, thorax, abdomen

What are the key features of Entognatha?

orders: protura, diplura, collembola

mouthparts retracted in head

wingless (apterygota)

are all ametabolous

What are the key features of Insecta?

Ectognathous mouthparts (outside of head)

(usually) two pairs of wings

external form and function

exoskeleton: sclerites that are connected by flexible joints

Head: one pair of antennae, pair of large compound eyes, three ocelli

What are the sclerite types surrounding each segment on each side?

It is hard, waterproof, and light (→ flight)

dorsal: tergite

ventral: sternite

lateral: pleurite

What are the 4 general mouthparts of Hexapoda?

Labrum

mandibles

maxillae

labium

What circulatory system does Hexapoda have?

open circulatory system

Indirect flight muscles

change shape of thorax, indirectly moving wings up or down

What are some examples of indirect flight muscle insects?

fly, butterfly, cricket

Direct flight muscles

attach directly to wing; one set raises the other set lower wing

What are some examples of direct flight muscle insects?

dragonfly, mayfly

What is the tracheal system for Hexapoda?

spiracles to trachea; trachea to tracheoles (1.5 mio)

diffusion of oxygen into cells

pumping movements aid in breathing as well

What are the 3 development patterns of Hexapoda?

Ametabolous (direct) development

Hemimetabolous (incomplete) metamorphosis

Holometabolous (complete) metamorphosis

What does ametabolous (direct) development do?

juvenile is a small, immature version of adult (egg → juvenile → adult; e.g., Collembola)

What does hemimetabolous (incomplete) metamorphosis do?

juveniles are nymphs without wings that grow with successive molts until final molt: winged adult

egg → nymph → adult

e.g., cicada, grasshopper, katydid

What does holometabolous (complete) metamorphosis do?

88% of insects

egg → larva (e.g., caterpillar maggot) → pupa → adult

pupal stage: metamorphosis, restructuring of body; overwintering

e.g., beetles, butterflies, flies

What are the sensing organs in Hexapoda?

Mechanoreception

auditory reception

chemoreception

visual reception

compound eyes

What do compound eyes consist of?

ommatidia

cornea and cone (focus and gather light)

photoreceptor cells

Rhabdom (contains photo receptor cells)

pigment cells (separate the light entering each ommatidium)

axons

Mechanoreception

touch, pressure, vibration detected by sensilla (seta connected to nerve cell)

Auditory reception

Tympana (e.g., orthoptera, lepidoptera) or sensilla can detect airborne sounds

What are examples of animals that have auditory reception?

moths, cricket, katydids, and others detect ultrasounds (→ bats)

Chemorecption

taste, smell; sensory cells on mouthparts, antennae, tarsi of leg

Visual reception

Ocelli (simple eye)

Compound eye

Ocelli

light intensity, day length

Compound eye

adults; thousands of ammatidia (bee: 6300)

What are the different defense mechanism for Hexapoda?

Aposematic coloration

Crypsis

Batesian mimicry

Mullerian mimicry

Aposematic coloration

warning coloration

e.g., toxicity, foul taste, being aggressive

Crypsis

camouflage

Batesian mimicry

animals copy appearance of noxious/dangerous species, even though they are not noxious/dangerous to avoid being eaten

Mullerian mimicry

two (or more) noxious animals develop similar appearance as a shared protective feature; share the cost of teaching inexperienced predators what not to eat. Lower death rate for mimics

What are the characteristic features of Echinodermata?

spiny endoskeleton of ossicles (calcareous plates): armor

Unique water-vascular system: hydrostatic system to move feet

Pedicellariae: pincers

Change symmetry; pentaradial symmetry (adults), larvae: bilateral symmetric

Do Echinodermata have a deuterostome or protostomes?

Deuterostome

What type of cleavage do Echinodermata have?

radial

What coelom do Echinodermata have?

Eucoelom (=true coelom)

What is the general body arrangement of Echinodermata?

central disc with five arms

body covered with ciliated, pigmented epidermis

mouth: under side (oral surface), other side: aboral surface

Ambulacral area/groove in Asteroidea

from mouth to tip of each arm

Water-vascular system in Asteroidea

Hydraulic system

opens to outside through: madreporite → stone canal → ring canal → radial canals in arms (ambulacral groove) → lateral canals → podia

Pedicellaria in Asteroidea

keep body clean, food capture, protect papulae

Papulae in Asteroidea

Dermal branchia (‘skin gills’) → projections of coelomic cavity: respiration

Tube feet (podium) in Asteroidea

they are protected by spines inside the groove

hollow, muscular tube with ampulla (fluid reservoir) and sucker

muscle contraction of ampulla forces fluid into tube feet, which hydraulically stiffens podia

longitudinal muscles in foot retracts it: fluid back into ampulla

contraction of longitudinal muscles on one side of podium bends foot into that direction

Catch-collagen in Asteroidea

can change from liquid to solid through nervous impulses (secs)

Ossicles in Asteroidea

Calcareous plates

bound together by connective tissue; embedded in epidermis

Nervous system in Asteroidea

decentralized nervous system

nerve ring in disc around mouth with radial nerves in each arm

plus epidermal nerve net

together: sensory input and coordination of locomotion of tube feet

sensory system responds to touch, chemical cues, temperature, orientation, light

What are the two larva types for Asteroidea?

Bilateral larvae → pentaradial juvenile

Brachiolaria larva → attachment to substrate and metamorphosis to juvenile

What is Ophiuroidea larva name (after egg)?

ophiopluteus larvae

How does Ophiuroidea differ from Asteroidea?

Ophiuroidea has no pedicellariae or papulae, ambulacral grooves covered with ossicles (closed), no suckers on feet (aid in feeding not locomotion), madreporite on oral surface, no ampullae for podia, no anus, no intestine

What is the larva after egg called in Echinoidea?

Echinopluteus larvae

Endoskeletal test in Echinoidea

shell made by ossicles

Aristotele’s lantern in Echinoidea

chewing mechanism with teeth

Evisceration

ejection of internal organs

Autotomy

self-amputation for self defense; avoids grasp of predator and/or confuses the predator

What are the 5 key features of Chordata?

Notochord

Dorsal tubular nerve cord

Pharyngeal pouches with slits

Endostyle

Postanal tail

What is the function of the notochord?

flexible, rod-like structure, extending through length of body

stiffens body and is attachment site of swimming muscles

lateral bending allows undulatory movement

in most vertebrates: notochord replaced by vertebral column

jawless vertebrates (agnatha) and amphioxus (cephalochordata) notochord exists throughout lifetime

What is the function of dorsal tubular nerve cord?

anterior end enlarged: brain

brain in skull (cranium)

nerve cord passes through neural arches of vertebrae (B)

Both: protection

What is the function of pharyngeal pouches with slits?

pharyngeal pouches with slits: pockets in pharynx

tetrapoda: give rise to Eustachian tubes, middle ear cavity, tonsils, and parathyroid glands

What is the function of endostyle?

protochordates (sea squirts, Amphioxus) and lamprey larva: secretes mucus to trap food particles in pharyngeal cavity

thyroid gland is derivative of endostyle

What is the function of postanal tail?

Postanal tail + muscles + notochord = motility (swimming)

humans: coccyx

What are the general features of Chordata?

bilateral symmetry

metamerism: muscles, vertebrae, ribs

has cephalization

has radial cleavage

deuterostomia

mode of coelom formation is enterocoely

Which group of ancestral fish gave rise to bony fish?

Acanthodians

What gave rise to jaws?

modifications from first two gill arches, muscles attached to these gill arches for ventilation of gills to meet increased metabolic demands

What are the 2 additional evolutionary milestones (vertebrata) and advantages of those milestones?

Jaws - firmly grasp objects (with teeth) and cut and grind food into pieces which expanded range of food sources

Paired pectoral and pelvic fins - jaws and paired fins paved way for diversification of vertebrates; more controlled swimming

What helps shark float?

pectoral fins and broad head provide lift

large liver (lipid squalence; 30%) with low density aids in buoyancy

cartilaginous skeleton much lighter than bones

What are the special senses of sharks?

Lateral line and ampullae of lorenzini

What does lateral line do in sharks?

sense vibrations, movement, and pressure gradient, current, orientation of body in water

What does Ampullae of Lorenzini do in sharks?

electroreceptors pick up electric field of prey animals

Anadromous life cycle

larvae hatch from eggs (freshwater) → burrows in sandy habitat: filter feeders (ammocoetes larva) → grow 3-7 years (freshwater) → metamorphose into adults move to sea → migration back into streams for reproduction after 1-4 years

What is an example of anadromous?

salmon

Catadromous life cycle

the opposite of anadromous

What is an example of catadromous?

eel

What adaptations in sharks help them swim?

Fusiform, heterocercal tail, many fins, median anal fin

What is fusiform in sharks?

spindle-shaped

What is heterocercal tail in sharks?

vertebral column turns upwards into dorsal lobe of caudal fin: thrust and life

What do the many fins help with sharks?

paired pectoral and pelvic fins, 1-2 dorsal fins: aid in mobility, stabilization, and steering

What does the median anal fin do in male sharks?

partly modified to claspers: used for copulation

What are the three modes of reproduction in sharks

oviparous, ovoviviparous, viviparous

Oviparous

lays egg in keratinized ‘mermaid’s purse’ that attached with tendrils to anything it touches

Ovoviviparous

eggs hatch in mother, developing young retained in uterus while nourished by yolk sac until born

Viviparous

embryos nourished through placenta or ‘utterine milk’; birth of live young

How do sharks osmoregulation?

osmolarity solution

retain nitrogenous compounds in extracellular fluid

body is slightly higher concentrated than sea water

no loss of water

Oophagy

developing embryos feed on unfertilized eggs in womb

Embryophagy

In Sand Tiger Shark and Grey Nurse Shark, embryos cannibalize each other; rich diet, strongest, healthiest and largest pups emerge; have already learned to hunt; the father’s genes of biggest offspring are passed on

What morphological trend have facilitated ecological diversity of Osteichthyes and Telostei?

mouth pump and operculum with muscles over gills (increased respiratory efficiency: increased metabolism and thus activity)

swim bladder (neutral buoyancy: remain suspended indefinitely at any depth with no muscular effort)

specialization of jaw muscles and skeletal elements allow more efficient feeding

What are the key features in Urochordata as juveniles and adults?

Sessile as adults

What are the key features in Ascidiacea as juveniles and adults?

only free-swimming larva bears all the Chordata hall marks

Metamorphosis: notochord and tail disappear, dorsal nerve chord becomes reduced to single ganglion

Adults: only pharyngeal slits and endostyle

What is the locomotion of Ophiuroidea and Asteroidea?

Arm movement

What are the three segmentation of the thorax in Hexapodas?

Pro-, Meso-, Metathorax-

What is attached to the metathorax in Hexapoda?

wings; each segment with one pair of legs

Chilopoda morphological differences from Diplopoda

venom claws to kill and then chew with mandibles

segment behind head and last two segments without legs; all other segments bear one pair of legs

last pair of legs has sensory function

pair of antenna, pair of mandibles, 1-2 pairs of maxillae

Diplopoda morphological difference from Chilopoda

millipedes

most are detritivore

roll into coil when disturbed

can secrete toxic/repellent fluids (lateral repugnatorial glands)

head and trunk tagmata

4 segments: each with one pair of legs (haplosegments)

Then, each abdominal segment: 2 pairs of legs (diplosegments)

last pairs of legs used for reproduction in males