Final Exam Flashcards
1
Q
What is neodermis?
A
specialized epidermis found in platyhelminthes specifically neodermata
2
Q
What is mesoderm?
A
muscles, circulatory system, other process
3
Q
What is triploblast?
A
-blastocoel fills with cells
-three germ layers
4
Q
What is cephalization?
A
concentrating sense organs in the head region
5
Q
what is the ectoderm?
A
layer that is in contact with the outside environment
6
Q
what is the endoderm?
A
layer that processes food
7
Q
what are true muscles?
A
-made of contractile cells
-develops from mesoderm
-muscles in cnidaria have a separate evolutionary origin
8
Q
what is primary bilateral symmetry?
A
-active, directed movement most efficient with an elongated body form with anterior, posterior, dorsal, and ventral sides
9
Q
describe the coelom of mollusca
A
-very small
-small chamber around the heart
10
Q
what is the mantle in mollusca?
A
-folds of tissue covering the viscera and mantle cavity
-produces the shell in some molluscs
-houses gills or lungs (gas exchange)
11
Q
describe the head-foot region in molluscs
A
-some have a well developed head
-radula (a ribbon like organ)
-foot is used for movement (adhesion, extend hydraulically, burrow into mud/sand, fin-like for swimming)
12
Q
describe the radula and its function
A
-ribbon like organ
-found in all molluscs except bivalves
-muscles move the radula
-used for scraping, piercing, tearing, cutting, and boring
-acts as a conveyor belt to move food towards the stomach
13
Q
describe the circulatory system of molluscs
A
-open circulatory system
-includes heart and some blood vessels
-vessels open to blood sinuses (larger open cavities)
-respiration involves a gill-like organ
13
Q
describe the circulatory system of molluscs
A
-open circulatory system
-includes heart and some blood vessels
-vessels open to blood sinuses (larger open cavities)
-respiration involves a gill-like organ
14
Q
describe the respiratory organ in molluscs
A
-found in most bivalves and some gastropods
-found in mantle cavity
-ctenidia (primitive gill)
-secondary gill or lungs in some gastropods
15
Q
general info of bivalves
A
-most are marine, some freshwater and some brackish water
-sedentary filter feeders
-create water currents with cilia
-no defined head
-no radula
-very little cephalization
16
Q
describe a bivalve shell
A
-2 shells held together by hinge ligament
-valves drawn together by adductor muscles (resting state is open shell
-umbo is the oldest part of the shell
-pearls are produced when an irritant enters between the shell and mantle (layers of nacre secreted around the foreign material)
17
Q
describe the general interior of the bivalve
A
-foot is in the midline
-modified ctenida on either side of the foot
-siphons are extensions of the mantle (incurrent and excurrent)
-siphons can be used to obtain food and O2 and are an adaptation of burrowing marine bivalves
18
Q
movement of bivalves
A
-not very mobile
-larvae are mobile
-scallops swim to escape from predators by creating a jet propulsion by clapping valves together
19
Q
respiration in bivalves
A
-some have modified gills to also collect food particles from water
-derived from primative ctenidia (lengthened filaments)
-filaments form plate like lamellae
20
Q
feeding in bivalves
A
-connected to respiration
-filter feeding
-particles enters the incurrent siphon
-gland cells on gills release mucus to capture particles
-cilia and palps direct the mucus and food to the mouth
21
Q
excretion in bivalves
A
-blood passes through nephridial tubules (kidneys) to remove waste
22
Q
nervous system in bivalves
A
-controlled by three pairs of ganglia with connected nerve cords
-simpler than annelids or arthropods
-sense organs are reduced and poorly developed
23
Q
reproduction in bivalves
A
-only sexual
-fertilization is external (gametes released through excurrent siphon)
-indirect development
-produce free swimming trochophore larva
-next is veliger stage
-then spat stage
-then adult
24
reproduction in freshwater bivalves
-internal fertilization (sperm enters the incurrent siphon)
-eggs fertilize in water tubes of gills
-larvae develop into glochidia stage (specialized veliger stage) (attach to gills of passing fish and are briefly parasites)
-cannot swim in this stage
-detach and sink to bottom as free living juveniles
25
zebra muscles vs native clams
-zebra muscles live on sediment or attached to hard surfaces
-zebra muscles form swimming trochophores and veligers
-native clams live burrowed in sediment
-native clams form non-swimming glochidia and must live on fish for a few weeks
26
general description of gastropods
-many have shells
-univalve
-shell is coiled or uncoiled
-development usually involves trochophore stage and veliger stage
-undergo torsion (rearranging of body during development of the adult)
27
explain torsion in gastropods
-initially the complex gut runs in a straight line (anterior to posterior) (mouth at top and anus, gills, and mantle cavity at the bottom)
-slowly the shells rotates 180° and the mantle cavity is over the head
-the gut and viscera also rotate
-finally the gastropod loses a gill and other paired organs and the head can be retracted into the mantle cavity
28
explain benefit of torsion in gastropods
-shell weight is more evenly distributed
-organs are lost so that excreted waste does not foul the gills (anus is by the head now)
-the coiling of the shell also pressed on the right side of the mantle cavity so organs were lost to compensate this
29
symmetry of gastropods
most are bilaterally asymmetrical
30
coiling of gastropod shells
-right-handed dextral
-left-handed sinistral
31
how do gastropods feed?
-well defined head and mouth
-have a radula (toothy ribbon that is used to collect food
32
what do gastropods feed on?
1. herbivores
-scape algae off surfaces
-forage for green vegetation
2. scavengers
-feed on dead and decaying matter
3. parasites
-of corals
4. predators
-use radula to tear at their pray
-bore holes into shells and proboscis to feed on soft tissue
-some have toxins that incapacitate prey
33
respiration of gastropods
-by ctenidia and mantle/ skin surface
-some have developed lungs and breath air (pulmonate snails)
34
nervous system of gastropods
-well developed
-brain (3 pairs of ganglia)
-ventral nerve cord
-sense organs (light, balance, touch, chemical)
35
reproduction of gastropods
-monoecious or dioecious
-indirect development
1. fertilization in water
-trochophore develops within the egg
-shelled eggs can be released to water column or attached to surface and veliger emerge
2. terrestrial and some freshwater
-fertilize internally within oviduct
-young snails emerge from egg but other life stages occur in egg
36
general description of cephalopoda
-marine predators
-sensitive to salinity
-no freshwater
-modified foot (mostly in the head with anterior end extending as a ring of arms)
-foot and mantle form a funnel shape called a siphon
37
locomotion of cephalopods
-forcefully expel water through siphon
-lateral fins (in squid and cuttlefish) stabilize and flutter to allow swimming motion
-octopuses can crawl along rocks/coral using arms
-some octopuses have webbing between arms and can also swim like a medusa
38
hunting in cephalopods
-capture prey with arms/tentacles
-draw food into biting range
-bite off pieces using hard beak
-digestion/ nutrient absorption in digestive gland
-radula also present
39
respiration in cephalopods
-have one pair of gills which are more specialized
-no cilia as it can't meet high O2 demand
-mantle musculature enlarges/ compresses to move water in and out
40
circulation in cephalopods
-highly active lifestyle cannot be accommodated with open circulatory system
-closed network of vessels
systemic heart leads to body + kidney, then to brachial hearts and into the gills
-this creates increased blood pressure in the gills
41
excretion in cephalopods
-contain metanephridia (similar to annelids)
-coelomic fluid/ blood filtered to remove waste
-waste is excreted into mantle cavity then out to the water
42
nervous system in cephalopods
-largest brain of any invertebrate
-can learn by reward, punishment, and observation of others
-use tools
-lack hearing but have tactile and chemoreceptors in their arms
43
eyes of cephalopods
-camera like eyes like humans
-complex eyes with cornea, lens, and retina
-excellent sight underwater
-although similar to human eyes, development is different (convergent evolution)
-visual signs are main form of communication
44
communication in cephalopods
-chemical and visual signals
-whole body colour change
45
colour change in cephalopods
-chromatophores are cells in the skin that contain pigment granules
-contractions in muscle fibres attached to chromatophores cause change in colour pattern
-colour change can happen rapidly
-can occur independently across the body
-some deep water cephalopods have luminescent organs
46
reproduction in cephalopods
-internal fertilization
-in male seminal vesicle sperm are packaged in spermatophores
-one male arm is modified as a copulatory organ (hectocotylus)
-removes spermatophore and inserts it in female genital opening (break off arm in opening)
-fertilized eggs leave oviduct and attach to stones
-hatch but without the free swimming larval stage
47
what are the 5 subphyla of the phylum arthropoda?
1. myriapoda (centipedes, millipedes)
2. chelicerata (spiders, horseshoe crabs)
3. Trilobita (trilobites- extinct)
4. Crustacea (lobsters, crabs)
5. Hexapoda (insects)
48
general description of arthropoda
-no cilia
-appendages with joints
-no nephridia
-haemocoel instead of coelom
-body segmented into tagmata
-hard protective exoskeleton containing chitin
-molt exoskeleton to increase in size (ecdysis)
49
stages of molt
premolt (rupture of membrane between abdomen and carapace) --> molt (old carapace separates and rises and abdomen emerges) --> intermolt
50
what the the exoskeleton?
-non-living (non-growing)
-made of chitin, protein, and calcium
-used by animal to move
51
what are the layers of the exoskeleton?
-over entire body, exoskeleton is made of plates joined by flexible hinges called sclerites
1. epicuticle
-thin epicuticle
-waxy texture
-no chitin
2. procuticle
-multiple layers
-chitin bound with protein
-lightweight and flexible
-protects against dehydration
-exocuticle is produced before molting
3. epidermis
-secretes cuticle
52
process of molt
-hormones begin process
-old cuticle separates from epidermis
-enzymes released to recycle procuticle
-new epicuticle and procuticle start to form
-animal expands and pushes on old exoskeleton
-as the animal exits, new cuticle is being secreted
53
general features of crustaceans
-all appendages except first antennae are biramous (two main branches)
-presence of nauplius larvae
-bilateral symmetry
-compound eyes
-2 antennae
-jointed appendages
-cuticular exoskeleton
-three tagamata (segments fused for common function)
-many have thorax fused with head to form cephalothorax
-non-segmented rostrum
-non-segmnted telson with uropods form tail
-dorsal covering (carapace)
54
appendages of crustaceans
-evolved from modifications of the basic biramous appendages
-used for eating, holding/crushing food, capturing prey, and walking
55
feeding in crustaceans
-filter feeding
-predation
-scavenging
-food is shredded by mandibles
-food is ground up by gastric mill
-passed into the intestine for digestion
56
respiration and circulation in crustaceans
-open circulatory system
-hemolymph is involved in gas transfer
-may have copper or iron containing pigment (Hemocyanin or Hemoglobin)
-have gills under carapace
57
excretory system of crustaceans
-green gland
-hydrostatic pressure of hemocoel forces fluid to filter into the gland
-resorption of salts and amino acids occurs as the filtrate passes the excretory tubule and bladder
-regulates the ionic/ osmotic composition of body fluids
58
nervous system of crustaceans
-similar to annelids
-fused ganglia throughout the body
-brain connects the eyes and two pairs of antennae
-subesophageal ganglion connects to brain and supplies nerves to the rest of the body
59
sense organs of crustaceans
-compound eyes
-statocysts
-tactile bristles (setae), mostly on mouthparts and telson
-chemical sensing of taste and smell occurs on setae
60
how do compound eyes work in crustaceans
-single unit is called ommatidia
-each unit works like a separate tiny eye
-contains pigment
-they can see in all directions simultaneously
-image is fuzzy
-transparent cuticle (cornea) covers the eye
61
reproduction in crustaceans
-dioecious
-most decapods brood eggs in brood chambers, attached to the abdomen or abdominal appendages
-crayfish develop directly without a larval form
-otherwise it is indirect development
-nauplius is the most common larval life stage (3 pairs of appendages all for swimming)
62
other important crustaceans
1. class maxillopoda (subclass copepoda)
-the eye is unique in structure
-small but important part of food web
2. class malacostraca
--order isopoda
-only truly terrestrial crustaceans
-need moist habitat
-also have marine and freshwater forms
-dorsoventrally flattened, lack a carapace, have sessile compound eyes
--order decapoda
-5 pairs of walking legs
- includes crayfish, lobsters, crabs, and true shrimp
-crabs have broader cephalothorax and reduced abdomen compared to crayfish and lobsters
63
what is a protostomes
mouth develops first in gastrula
64
what is a deuterostome
-anus develops first in gastrula
-includes: echinodermata, hemichordata, chordata
65
what are the 5 classes of echinodermata?
1. asteroidea (sea stars)
2. ophiuroids (brittle stars)
3. holothurians (sea cucumbers)
4. Echinoids (sea urchins)
5. Crinoids (sea lilies)
66
what is the general form of asteroidea?
-ambulacral area from mouth to each tip of arm
-ambulacral groove bordered by podia
-movable spines surround and protect the podia cover much of animal surface
-radial nerve occurs just below thin cell layer in the center of the groove
-endoskeleton lies under the radial nerve, extend into spines
-endoskeleton made of calcareous plates (ossicles)
-contains catch collagen that can be controlled to change from liquid to solid
-papulae are small projections of coelomic cavity (gas exchange and excretion)
67
what is the water vascular system in asteroidea?
-used for movement, food-gathering, respiration, excretion
-hydraulic system that uses muscular pressure to coelom
-ampulla are muscular sacks that hold fluid above the podia --> contraction forces fluid into the podia and stiffens them for walking (creates suction cup)
68
feeding and digestion in asteroidea
-cardiac stomach can be everted through the mouth
-upper stomach is smaller and connected to digestive glands
-digestion is mostly extracellular
69
nervous system of asteroidea
-tube feet connect to central nervous system
-no brain
-all podia move in one direction but not in unison
-cutting a radial nerve ends coordination in one arm
-cutting a circumoral nerve ring stops all movement
70
sense organs in asteroida
-tactile organs are scattered over the surface and an ocellus (simple eye) at the tip of each arm
-reacts to touch, temperature, chemicals, and light
-mainly active at night
71
reproduction in asteroidea
-sexes separate in most species
-pair of gonads in each arm
-fertilization is external
-gametes are shed into the water in early summer
-indirect development
-bilateral symmetry in larvae
-arms can regenerate if at least one fifth of the central disc is present
-can voluntary lose arms (to escape predators)
72
general info about brittle stars
-organs contained in central disc
-entire arms are moved in pairs for locomotion (no tube feet)
-5 movable plates act as jaws and surround the mouth
-no anus
73
general info about sea cucumbers
-extended along oral-aboral axis
-suspension/deposit feeders
-trap particles on the mucus of tentacles, ingesting particles in pharynx
-cast out part of viscera when irritated (organs of cuvier) (sticky and have a toxin)
-breathe through their butts
74
general info about sea urchins
-outer covering is row of hard plates with moveable spines
-may produce toxins to paralyze prey
-eaten by sea otters
-can cause urchin barrens if numbers not controlled
-feed on algae or detritus
75
general info about sea lilies
-"upside down" compared to others echinoderms
-stretch arms to feed on plankton and suspended particles
-can attach to surface with a stalk or can swim
-arms resemble feathers
-upper surface has mouth that opens into esophagus and intestine
-tube feet and mucous nets allows it to feed on small organisms in the ambulacral grooves
-live attached most of their life
-deep water species
76
general info about annelida
-segmented worms
-triploblasts
-bilateral symmetry
-outer covering (cutile)
-eucoelomates (hydrostatic skeleton, longitudial and circular muscles surrounding the body)
-2 cavities (gut and coelom)
77
what is metamerism?
-independent movement of each segment
-needs more complex nervous system
-if one segment is injured the animal can still function
78
what class do earthworms belong to?
clitellata
79
describe the class clitellata?
-all have a clitellum
-most found in freshwater or moist terrestrial environment
-marine and parasitic forms as well
80
clitellata response to stimuli
-2 cerebral ganglia for processing stimuli
-ventral nerve cord travels length of body
-pair of ganglia in each segment
-giant axons in ventral nerve cord for rapid escape movement
81
movement in clitellata
-contract circular muscles (segments become elongated)
-contract longitudinal muscles (segments become short and wide) (helps anchor body)
-setae
82
describe setae in clitellata
-aid in movement
-extend from pores in cuticles
-act as anchors in earthworms
-moved by muscles
-4 pairs per segment
-helps anchor body and facilitate movement
83
feeding in clitellata
-scavengers
-food in the mouth, moves to pharynx, crop, gizzard
-digestion/absorption at intestine
-waste released at anus
84
respiration in clitellata
-no specialized organs for respiration
-moist skin allows passive transfer of gases across body covering to blood
-hemoglobin in blood carries oxygen, carbon dioxide released
-circulatory system is present to allows gas exchange throughout body
85
excretion in clitellata
-some releases excess water/salts at skin
-specialized organ (Nephridia) 2 per segment
86
nephridia in clitellata
-opening to coelom and outside animal
-coelomic fluid passes through
-selective resorption as fluid passes through
87
reproduction in annelids
-sexual reproduction
-no asexual reproduction
-some clitellates reproduce asexually by budding
-direct development
-no metamorphosis
-juveniles resemble adults, but smaller
88
what is the clitellum
-ring of secretory cells
-secretes mucous to join worms
-always visible in oligochaetes
-only visible during mating season in leeches
-monoecious
-sexual organs at segments 9-15
-mutual insemination
-clitellum produces cocoon where fertilization occurs
-both partners produce cocoon
-young worms emerge in 2-3 weeks
89
what do earthworms do?
-intestines of the soil
-breakdown of organic matter and mixing of soils
-sign of healthy soil
-important as a food source for birds, snakes, mammals, invertebrates, etc
90
what are Errantia?
-free moving annelids
-traditionally called polychaetes (having setae)
-mostly marine, some freshwater
-can be very abundant
-important food source
-well differentiated head; parapodia sense organs
-more sense organs than clitellates
-some somites specialized
91
general info about polychaetes
-predators/scavengers
-head: 2 sections with eyes and other sensing organs, surrounded by mouth and may have setae or chitinous jaws
-tail: tubular, complete gut ends at the anus
92
respiration of polychaetes
parapodia
-paired appendages
-bundles of setae
-multifunctional
-contain respiratory capillaries
-may have gills
-paddle-like shape and strong musculature
-sensory cirri present
-lost in other annelids
93
excretion of polychaetes
-nephridia (2 per segment)
-same as in earthworms
94
reproduction of polychaetes
Asexual reproduction
-fission, fragmentation (pieces regenerate), or budding in some species
Sexual reproduction
-most dioecious
-M/F gonads develop temporarily and gametes released
-fertilization occurs externally
-early larvae are called trochophore larvae
-indirect development
-some cycle between: sexually immature atokes and epitokes where posterior swells with gametes and they break off
95
what are sedentaria?
-tube dwelling annelids
-found in freshwater, marine, or terrestrial
-some are parasitic
-bodies are similar to Errantia (mostly)
-heads may have long tentacles for food capture
-parapodia are reduced in size, specialized as an anchor
96
feeding in sedentaria
filter or deposit feeder
97
respiration in sedentaria
use gills
98
what are oligochaetes?
in the class clitellata and can be freshwater and parasitic
99
general info about freshwater oligochaetes
-smaller than terrestrial
-more conspicuous setae
-more developed sense organs
-benthic
-important food source for fish
100
what are animals in the order hirudinea
-in class clitellata
-leeches
-mostly freshwater, some marine, some terrestrial
-no setae
-body has 34 segments
-suckers on anterior and posterior end
-monoecious
-clitella only visible during mating
101
feeding of leeches
-many species are predatory on small invertebrates
- some climb trees to reach vertebrates
-temporary/permanent parasites (feed on blood)
-have cutting plates or jaws for cutting tissue
-salivary glands for releasing anesthetics and anticoagulants
102
respiration and excretion in leeches
-gas exchange through skin
-nephridia for excretion
103
nervous system of leeches
-very sensitive in presence of prey
-will often attach to objects smeared with fish cells, oil secretion, sweat, etc
-if they feed on mammals they are attracted to body heat
-have sensillae that are clusters of sensory cells
104
reproduction in leeches
-clitellum develops only during breeding season
-monoecious but need mating partner
-cocoon secreted as fertilization occurs as it moves
-similar to oligochaetes
105
general info about hexapods
-six legs
-all legs are uniramous (segments attach end-to-end without splitting)
-have 3 body segments (tagmata): head, thorax, abdomen
106
general info about the class Insecta
-base of mouth parts outside of head capsule
-most have 2 pairs of wings on thorax
-more species of insects than other animals combined
-integral role in environment, and medical and economic roles in human life
107
important info about adult insects
-mouthparts outside of head capsule
-2 pairs of wings
-no appendages on abdomen
-3 tagmata
108
metamorphosis in hexapoda
-exoskeleton must be shed between stages (multiple stages in life)
-exoskeleton limits body size
-each shed is a molt (ecdysis)
-each stage between molts is called an instar
109
incomplete metamorphosis
-Hemimetabolous
-gradual change
-young are called nymphs (wing-less)
-bud-like growth of wing pads in early instars shows where wings will develop
-egg--> nymph--> adult
-grasshoppers, dragonflies, etc
110
complete methamorphosis
-Holometabolous
-about 88% of insects undergo complete metamorphosis
-larvae and adults often live in completely different environments and have different morphology
-after many larval instars the larval moth or butterfly become a pupa inside a cocoon or chrysalis
-often pass the winter in cocoon or chrysalis
-adult emerges as the final molt
-egg--> larva--> pupa--> adult
111
movement of insecta
-legs can be modified for walking, jumping, burrowing, swimming, grabbing prey, and collecting pollen
-walking usually involves a triangle of legs moving at a time (improves stability)
-wings are outgrowth of cuticle from the throax
-not homologous to bird or mammal wings
-wings can be used for flight or protection
-2 pairs of wings, only true flies have 1 pair
112
explain flight control of insecta
-muscles controlling wings
-can flap wings directly
-can change the shape of the body (indirectly moving the wings)
113
feeding of instecta
-most feed on plant fluid or tissue
-many beetles and insect larvae feed on dead animals
-some insects catch live prey
-many insects are parasitic at some point in their lives
-many wasps are parasites that always kill their host (parasitoid)
114
digestion of insecta
1. foregut
-mouth, esophagus, crop, gizzard
2. midgut
-stomach, gastric ceca
-primary site of digestion and absorption
-ceca may increase digestive and absorptive area
3. hindgut
-intestine, rectum, anus
-primary site for water absorption
115
circulation in insecta
-open circulatory system
-muscular heart similar to crustaceans
-blood (hemolymph) does not transport oxygen in most insects
-hemolymph also pumped by muscular pumps around the body and by animal movement
116
respiration in insecta
Tracheal system
-network of thin walled tubes that branch into the body
-hard taenidial ring supports the structure
-allows gas transport without oxygen carrying pigment
-"exhale" when muscles contract in movement. increased exoskeleton pressure contract the tracheae
-"inhale" when muscles relax and taenidial ring recoils. the tracheae expands
117
excretion and water balance in insecta
-malpighian tubules carry out waste
-tubules vary in number but join between mid and hind gut
-blind end allows transfer from hemolymph
-main waste product is uric acid
-rectal glands absorb water
118
nervous system of insecta
-similar to annelids brain (fused nerve cells, or ganglia but more)
-antennae used as sense organs
-other sense organs are microscopic
119
sense organs in insecta
1. Touch
-also pressure and vibration
-single hair like setae
-common on antennae
2. hearing
-sensitive setae detect airborne sounds
-organs on legs detect vibrations
-membrane like Tympanal organs
-important in insects hunted by bats
3. taste and smell
-bundles of sensory cells in sensory pits
-located on mouthparts, antennae, and legs
-important for feeding, mating, host-parasite relationships
4. sight
-2 types: simple and compound
-simple eyes have a single lens focusing on the retina
-compound eyes have many lenses focusing on retina
120
reproduction in insecta
-sexual reproduction is common
-parthenogenesis is important in some life cycles
-attracting mates can be done through: smelly pheromones, flashy bioluminescence, loud calls, seductive courtship movements
-fertilization occurs internally
-females mate only once and store sperm for the rest of their lives
-females can either lay a few eggs and care for them or many at once
-environmental cues cause changes to the production of hormones that cause molting
-diapause
121
what is lepidoptera?
-order of insecta
-butterflies and moths
-wings covered in scales
-mouthparts are tubes used to drink/suck nectar
-caterpillars (larvae) with chewing mouthparts, silk glands for making cocoon
122
what is hymenoptera?
-order of insecta
-ants, bees, wasps
-narrow wings
-mouthparts for chewing or lapping liquids
-ovipositor sometimes specialized as stinger
-larvae are mostly legless, blind, maggot like
123
what is trichoptera?
-order of insecta
-caddisfly
-aquatic larvae and pupae
-pair of simple eyes
-chewing mouthparts
-3 pairs of thoracic legs
-posterior hook like appendages
-many form cases or trap food in nets
124
what is ephemeroptera?
-mayfly
-nymph aquatic
-three tail filaments
-lateral or ventral external gills
-single claw at the end of each leg
125
what is coleoptera?
-beetles, fireflies, weevils
-aquatic larvae
-variable in structure
-highly sclerotized (dark colour)
-prominent mouthparts for biting and chewing
-protective front wings that are thickened
126
what are diptera?
-true flies
-house flies, fruit flies, mosquitoes
-aquatic larvae
-lack segmented thoracic legs (fleshy prolegs)
-head sclerotized
-single pair of wings
-sucking mouthparts
127
what are the characteristics of chordates?
1. dorsal nerve cord
2. notochord
3. endostyle
4. pharyngeal pouches
5. postanal tail
128
what is the notochord?
-always found at some embryonic stage
-can bend without shortening and permits undulation
-flexible but stiff tissue
-extends the length of the body between the gut and the nervous system
-acts to stiffen the body, providing skeletal scaffolding for the attachment of swimming muscles
-first nerve chord but not bony
-in most vertebrates the notochord was replaced by vertebrae
129
what is the dorsal tubular nerve cord
-key component of the nervous system
-in most invertebrate, never cord is solid and ventral to digestive tract
-in chordates, single tubular cord is dorsal to digestive tract and anterior end enlarges to for the brain
-in vertebrates, the nerve cord passes through protective vertebrae and brain is protected by cranium
130
what are the pharyngeal pouches and slits
-pharyngeal slits lead from pharyngeal cavity to the outside environment or forms a pocket
-in protochordates, it forms a slit for filter feeding
-in fish, pharynx further transformed and makes up internal gills
-in humans, make up part of middle ear, ear drum, tonsils, and other structures
131
what is the endostyle or thyroid gland
-found in chordates and no other animals
-some cells in endostyle secrete proteins (homologous to hormone secreting thyroid gland)
-secretes mucus in ancestral chordates to aid in filter feeding
132
what is the postanal tail
-allows swimming
-efficiency increased in fishes
-became smaller or vestigial later
-lost at around 4 weeks in human fetus
133
what are the 3 major subdivisions of chordates?
-craniata or vertebrata
-tunicata or urochordata (marine)
-cephalochordata (marine)
134
general info about cephalochordata
-commonly called lancelets and amphioxus
-about 29 known species
-found in sandy bottom of costal water
-filter feeders
-similar to chordates prior to vertebrates
135
characteristics of amphioxus
-water enters mouth by cilia into buccal cavity and pharynx
-water passes through pharyngeal slits where food is trapped by muscous secreted by endostyle
-food moved through gut by cilia and digested by phagocytosis
-closed circulatory system but no heart
-respiration at body surface
-no hemoglobin
-excretion via organs similar to nephridia
-dioecious, fertilize externally and have direct development
136
what are ascidiacea
-found subphylum tunicata
-about 3000 known species
-commonly called sea squirts
-found in all seas at all depths
-filter feeders
-can be colonial or solitary species
-water brought in through incurrent siphon and out through excurrent
-traps food in mucus net and cilia move food to stomach
-one nerve ganglion
-no respiratory or excretory system in most
137
what are thaliacea
-part of tunicata subphylum
-pelagic
-colonial
-often bioluminescent
-includes salps and pyrosomes
-monoecious with single ovary and single teste
-external fertilization
-have all 5 chordate features as larvae but lose many as they develop
138
general info about craniata
-all have cranium enclosing the brain
-cranium and skeleton may be made of cartilage or bone
-endoskeleton supports body and allows for much larger body size
-muscles attached to endoskeleton allow movement
-cartilage skeleton developed prior to bone
-bone is stronger than cartilage and superior of muscle attachment
-some still have skeleton of cartilage
-bones may have evolved for mineral regulation
139
what are the two types of skeletons
Axial
-skull
-vertebral column
-ribs
-sternum (in tetrapods)
-medial fins
Appendicular
-limbs
-pectoral girdle
-pelvic girdle
140
what are the major vertebrate classes?
-jawless fish (hagfish, lamprey)
-cartilaginous fishes (sharks, skates, and rays)
-bony fishes (trout)
-amphibians
-reptiles and birds
-mammals
141
what are ray-finned fish
-fins are supported by bone or spines which are connected to the skeleton
-skin over the bone to be web-like fin
142
what are Actinopterygii
-class
-ray-finned fishes
-in infraclass Teleostei
-make up 96% of all living fish and half of vertebrates
-found from high altitudes to great depths
-large temperature range
-marine and freshwater
-specialized scales, fins, and tails allow great mobility
-changes in jaw structure allow new types of prey to be caught
143
what characteristics are true for all vertebrates
-blood transports nutrients, gases, and other substances
-ventral 3 chamber heart
-red blood cells contain hemoglobin
-have paired glomerular kidneys to remove metabolic waste products and regulate body fluid composition
144
what is the swim bladder
-filled with air for buoyancy
-gas diffuses to fill bladder
-also involved in sensing
145
info about scales
-light and allow mobility
-capture prey easier and escape predators better
-teleost scales overlap which reduces drag
-grow by adding outer rings
146
nervous system of teleosts
-anterior end of dorsal tubular nerve is enlarged to form a tripartite brain (forebrain, midbrain, hindbrain)
-brain protected by cranium
-weberian ossicles allow sensing of sounds as vibrations within inner ear (small bones) (primarily freshwater)
-transfer vibrations from the swim bladder to the inner ear
147
feeding of teleosts
-evolutions of jaws meant new types of food not just filter feeding
-most fish are carnivores
-fish (mostly) cannot chew their food (would block water flow to gills)
-swallow food whole
-modified jaw produces a pucker that sucks food into mouth from negative pressure
148
respiration in teleosts
-gills are filaments with thin membranes as plate like lamellae
-gills located inside pharyngeal cavity and covered by the operculum
-gas surface occurs at surface of gills
-water flow controlled by pumping of operculum (some may use ram ventilation)
-water continuously flows over gills
-water flow is opposite to blood flow
-countercurrent exchange maximizes exchange of gases
149
water balance in teleosts
-osmotic regulation occurs at the gills
-freshwater is hypotonic to fish blood
-water enters body and salt is lost by diffusion
-scaled and mucous covered body is mostly impermeable but gills allow water and salt fluxes
150
freshwater fish water balance
-hyperosmotic regulators
-kidney pumps excess water out
-special salt absorbing cells located in epithelium actively move salt ions from water into fishes' blood
-the system is efficient and the fish spends little energy on this
151
marine fish water balance
-hypoosmotic regulators
-blood is hypotonic to seawater
-low blood salt compared to sea water means they would lose water at gills
-must drink in seawater but this brings in more salt
-salt-secreting cells in gills
-salt ions not absorbed from waste
-kidneys do not absorb salts
152
reproduction in fish
-most are dioecious with external fertilization
-some are ovoviviparous fish that develop in ovarian cavity (embryo develops in egg in mother until ready to hatch)
-some sharks are viviparous with some kind of placental attachment to nourish young (live birth)
-most are oviparous pelagic fish that lay large numbers of eggs with no development inside mother
153
salmon in canada
-fish farming has grown a lot in past decades
-salmon are anadromous (grow up in sea, spawn in freshwater)
-atlantic salmon make repeated spawning runs
-pacific salmon spawn once and die
154
pacific salmon (sockeye) life cycle
-migrate downstream
-roam pacific for 4 years
-returns to spawn in parents' stream
-young fish are imprinted with odour of their stream
-can migrate to stream by sensing earth magnetic field or angle of the sun and then smelling their way home
155
features that unite bony fish to tetrapods
-bone replaces cartilage during development
-lung or swim bladder is present
-have several unique cranial and dental characteristics
156
what characteristics made it possible for aquatic animals to explore terrestrial habitats
-air-filled cavity functioned as a swim bladder
-paired nares used as chemoreceptors (used to draw in air on land)
-bony elements of paired fins that were used for movement under water were still used for locomotion on land
157
what first made the transition to land?
-vascular plants
-pulmonate snails
-tracheate arthropods
158
what physical differences must be addressed moving onto land
-oxygen is 20 times more abundant in air than water
-air is 1000 times less dense which means it provides less buoyancy and skeleton must support more weight
-air fluctuates in temperature more rapidly than water and body must adjust to this
-manage water loss
159
tetrapods vs fish
-stronger backbone
-muscles to support body in air
-muscles to elevate head
-stronger shoulder and hip girdles
-more protective rib cage
-modified ear structure to detect airborne sounds
160
general info about class amphibia
-eggs must be kept moist
-larvae depend on gills for respiration
-thin skin loses water quickly so must be kept moist
161
life cycle of a frog
-male fertilizes eggs as they are shed from female
-embryo nourished by yolk
-tadpole begins feeding on algae and has external gills
-skinfold grows over external gill, and water exits through spiracle
-hindlimbs then forelimbs emerge
-tail shortens by reabsorption, metamorphosis is near completion
-sexually mature at 3 years
162
salamanders
-burrow but some aquatic forms have lost their limbs
-carnivorous
-most have aquatic larvae and terrestrial adults
-some lay eggs in water
-some lay eggs on land under logs or in soft earth
-only terrestrial species undergo direct development
163
frogs and toads
-must live near water source (for reproduction and skin)
-all have tailed larval stage (tadpole) and tailless jumping adults
164
what are amniotes?
-arose from amphibian like tetrapod
-changes in skull represent changes in jaw musculature
-eggs adapted to be laid on land
165
adaptations of amniotes eggs
amniotic egg
-allows larger, faster growing embryos
- all have 4 membranes:
1. amnion
-cushions the embryo and provides an aqueous medium for growth
2. allantois
-holds metabolic waste
3. chorion
-highly vascularized respiratory surface
4. yolk sac
-nutrient storage
166
other adaptations of amniotes
-no gills in larvae which means a fully terrestrial life cycle
-internal fertilization
-thicker, water proof skin which means no capacity for respiration
-lungs are primary site of respiration
167
class Aves
-inhabit all biomes
-forelimbs are wings with feathers (lift and propulsion)
-efficient respiratory system (meet high oxygen)
-light "hollow" bones (provide light but rigid airframe
168
feathers
-homologous to reptile scales
-hollow quill emerges from skin follicle and continues as the rachis (shaft)
-rachis has numerous barbs
-several hundred barbs are arranged to form flat webbed surface (vane)
-up to 600 barbules in each side of barb
-barbules overlap and zip together with tiny hooks
169
skeleton of aves
-must be light to fly
-bones are pneumatized to reduce mass (have branching structure on inside but filled with many air cavities
170
respiratory system of aves
-very different from all other tetrapods
-have lungs with air sacs lining the sides
-have parabronchi inside lungs
-large portion of air bypasses lungs and flows directly into air sacs on inspiration
-on expiration, oxygenated air flows through lungs
-on second inspiration air flows into another air sac
-on second expiration, air flows out
-takes 2 cycles for a single breath to pass through system
-most efficient system for vertebrates
171
what are air sacs used for?
-helps cool bird during vigorous exercise
-air sacs extend into bones, legs, and wings, providing buoyancy
172
key characteristics of mammals
-synapsid skull
-hair
-mammary glands
-fertilization occurs internally and care for young
-warm-blooded (regulate blood temperature internally)
-sweat glands are common to cool the body (aquatic and with thick fur have lost or reduced sweat glands)
173
hair in mammals
-hair follicle is epidermal but lies in dermis of skin
-grows continously by rapid proliferation of cells in the follicle
-cells in hair shaft are shifted upwards away from their source of nourishment
-they accumulate keratin and die
174
different hair structures of mammals
-deer have brittle hairs
-wolverine have hollow hairs
-rabbits have hair that are scaled and interlocked
-sheep have curly hair that grows from curved follicles
175
molting of hair
-periodic molts of the entire coat
-foxes and seals shed once every summer
-most mammals molt twice, in the spring and fall
-some molting changes fur colour for better camouflage
176
patterns in hair
-patterns are disruptive and conceal animal (camouflage)
177
whiskers
-vibrissae
-sensory hairs
-provide tactile sense for nocturnal animals
178
true horns
-ruminants have them
-hollow sheaths of keratinized epidermis
-surround a core of bone rising from the skull
-usually not shed or branched but can curve
-grow continuously and both sexes have them
179
antlers
-occur in deer family
-composed of solid bone when mature
-develop annually in spring with highly vascular soft skin (velvet)
-only males have antlers except for caribou
-just before breeding season, velvet is removed by rubbing against trees
180
what are the 3 categories of mammals
1. monotremes
-non-placental egg laying
2. marsupials
-protect/ feed their young in an external pocket/pouch
3. eutherians
-nourish their young internally through the placenta
181
more info about monotremes
-lay eggs once a year
-eggs fertilized internally before leathery shells form
-no gestation period (all nutrients contained within egg)
182
more info about marsupials
-primitive placenta
-embryo initially surrounded by shell membrane and "hatches" internally and absorb nutrients from yolk sac and sits on uterine wall
-brief gestation period
-born very early in development
-continue to develop in pouch
183
more info about eutherians
-placental mammals
-embryo nourished in uterus via placenta
-long gestation period
-generally fairly developed upon birth
184
what is the placenta
-organ made of embryonic and maternal tissues with extensive blood supply
-supplies the embryo with nutrients, and oxygen, and it removes waste chemicals and CO2
185
what are turbellaria?
-class of platyhelminthes
-found in marine, freshwater, and terrestrial
-differentiated by pharynx and gut
-macrostomida
-polycladia (folded pharynx and very branched gut)
-tricladia (3 branched gut)
186
feeding of turbellaria
-mostly carnivores
-feed on annelids, molluscs
-incomplete gut
-extend pharynx to find prey, then release digestive enzymes on prey, and suck up remains
-gut lined with phagocytic cells which continue digestion
187
movement in turbellaria
-cilia in smaller members
-muscle contractions
188
what are rhabdite cells
-secrete protective mucous sheath
-located in epidermis
-prevents drying in terrestrial species
189
gas transfer in turbellaria
-across epidermis
-no special organs
190
excretion and osmoregulation in turbellaria
-specialized organs
-have protonephridia that regulates excess water
-found in most platyhelminthes
191
function of protonephridia
-functional unit is the flame cell
-flagella move fluids to collecting ducts
-wall of duct has microvilli to resorb ions and water
-some metabolic waste is lost this way (most lost by diffusion across cell wall)
-collecting ducts join and empty at nephridipores
192
sensing the outside world
-distinct brain (cerebral ganglion)
-thickened mass of nerve cells
-neurons specialized for sensory and motor
-have ocelli (sense organs)
193
sense organs of turbellaria
-locomotion favoured cephalization and evolution of sense organs
-ocelli are light sensitive eyespots
-tactile and chemoreceptive cells abundant in auricles
-statocysts (equilibrium) and rheoreceptors (direction of water currents) are present in some
194
reproduction in turbellaria
Asexual
-fission
-sometimes form zooids (temporarily attached offspring)
Sexual
-mainly monoecious
-fertilize eggs in a cocoon attached to rocks or plants
-juveniles resemble adults in freshwater
-marine juveniles are ciliated larvae
195
what are neodermata?
-parasitic platyhelminthes
-have neodermis
196
general info about trematodes
-in neodermata
-endoparasitic (mostly vertebrates)
-leaf like shape
-1or more suckers
-more than 1 host
-"fluke"
197
general info about monogeneans
-in neodermata
-ectoparasitic (mostly fish)
-posterior hooks
-1 host
-"fluke"
198
general info about cestodes
-tapeworms
-in neodermata
-endoparasitic (vertebrates)
-anterior scolex with suckers, hooks, and spines
199
trematodes
Structural adaptations for parasitism
-attachment organs (suckers and hooks)
-gland cells for host penetration structures or cysts
-high rate of reproduction
have well developed gut (blind gut)
200
fasciola hepatica
-sheep liver fluke
-adult fluke on liver
-eggs pass in feces
-miracidia (larva) ends up in water
-burrows into snail and eats gonads and creates sporocysts
-transform to radiaae and replicate time (2 generations)
-form into cercaria
-swim to vegetation and wait to be eaten
-eaten by sheep as metacercaria
201
schistosoma
-blood fluke
-common in Africa, South America, West Indies, and Middle and Far East
-dioecious
-3 species in humans (mostly): S. mansoni, S. japonicum, S. haemotobium
-borrow into human skin
-get to the liver through blood
-develop into adult in liver
-eggs get passed in feces
-egg hatches in water
-miracidium burrows in snail where sporocyst develops
-then sexual reproduction occurs in water as cercariae
202
cestodes
-rely on host's digestive tract
-absorb digested nutrients
-have no gut
-almost all have 2 or more hosts
-scolex is followed by series of reproductive units (proglottids)
-muscles, excretory, and nervous system similar to other flat worms
-no sensory organs
-most are monoecious, some are dioecious
-absorb nutrients through tegument
-have projections coving body surface to increase surface area to absorb nutrients
203
the beef tapeworm
-juveniles live in intermuscular tissue of cattle
-mature adults can reach over 10m with over 2000 proglottids
-well cooked and pre frozen beef kills cysticercoids
live in definitive host
-live in human attached to epithelium of small intestine
-sheds sexually fertilized eggs that are released in feces
-sperm is released and swims to gravid proglottid
-self fertilization is common but cross fertilization is optimal
204
the pork tapeworm
-juveniles live in muscles of pig
-both adult and cysticerci develop in humans
-migrate to various organs to form cysticerci including the eyes and brain
-cysticercosis can lead to blindness, serious neurological symptoms, or death
