Transcript Bilateral - El Camino College

Animals
1.
2.
3.
4.
5.
6.
7.
heterotrophs
multicellular
lack cell walls
move from place to place
most reproduce _________
characteristic pattern of ___________
possess unique tissues
Symmetry-embryonic layers
lack of symmetry:
•
•
Sponges
Radial :
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body arranged around a central axis
cnidarians
_____ embryonic layers
1.
outer ectoderm= epidermis
2.
inner endoderm= gastrodermis
bilateral:
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body has left and right mirror images
_____________
____ embryonic layers
1.
Ectoderm= epidermis
2.
Endoderm= gastrodermis
3.
Mesoderm= skeleton, muscles
Body Cavity
Improves the animal body design:
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1.
2.
3.
Circulation: fluids that move
Movement: fluid makes the animal’s body rigid permitting
resistance to muscle contraction
organ function: organs function without being deformed by
surrounding muscles
Bilateral animals:
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Acoelomate: no cavity
Pseudocoelomate: cavity between mesoderm- endoderm
Coelomate: cavity within the mesoderm
Segmentation
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building of a body from a ________ of similar
segments
a small change produces a new kind of
segment with a different __________
Embrynic development
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cell divisions of the fertilized egg:
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Compact ball of cells: __________
hollow ball of cells: _______
Indentation of the blastula: blastopore=
opening to the outside
protostomes, mouth develops from the
blastopore
 deuterostomes, anus develops from the
blastopore, mouth from other part of the blastula
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Sponges
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Porifera
lack tissue/organs
masses of specialized
cells embedded in a gellike matrix
perforated by tiny holes
flagellated cells line the
body cavity and draw
water in through the
pores:
______________
Cnidaria
Ex: jellyfish, hydra,
corals, sea anemones
radial symmetry
extracellular
digestion: digestion
outside of cells in a gut
cavity
___________: capture
their prey with
tentacles
2 basic body forms
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Jellyfish
Medusae: free-floating
Polyps: sessile
Sea anenome
Flat worm
platyhelminthes
simplest bilateral animals
lack internal cavity
digestive cavity only has one opening: cannot
_________________________
lack circulatory system, thin-bodies= diffusion
Reproduction:
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1.
2.
3.
4.
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hermaphroditic
asexual regeneration
Round worms
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Nematoda
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hydrostatic skeleton: muscles work against the
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fluid
unsegmented worms
cylindrical body
Ex:
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genetic and development studies: Caenorhabditis elegans
parasites:
1.
Trichinella: trichinosis= consuming undercooked pork
2.
Heartworm (dogs)
3.
Ascaris lumbricoides: intestines
Hollow worms:
annelids
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Ex: Earthworm, leeches
A tube __________________
repeated segments, excretory and
locomotor organs are repeated
Specialized anterior segments contain
sensory organs and brain
circulatory and nervous system
Mollusks
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_________ (with real cavitites)
without segmented bodies
basic body design
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foot: muscular structure
central visceral mass: body’s organs
mantle: surrounds the visceral mass
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radula, a rasping tongue-like organ
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________ formed (clams, oysters) when foreign
objects are lodged between mantle-inner shell, the
mantle coats the foreign object with layer upon layer
of shell material to reduce irritation
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Gastropods: snail
 foot to crawl, mantle for protection
 __________________
Bivalves: clam
 two-part shell with a hinge
 filter-feed by drawing water into their shell
Cephalopods: octopus
 modified mantle cavity that permits
____________
 shell is reduced or absent
Arthropods
• Biggest group, most successful!
• _____________:
•surrounds body for protection
•and keeps water in
• Molt
• ___________ symmetry
• Complex organs system! sensory, respiratory, social
behavior
• divisions: crustacean, millipede (and centipede), arachnids, insects
Echinoderms
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first deuterostomes
spiny skin= endoskeleton
Larva is __________but adult ______
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water vascular system: fluid-filled canals
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that extend into numerous hollow tubefeet for locomotion
Chordates
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Deuterostome: coelomates
large animals
________, flexible rod beneath the nerve cord
in the early embryo
_______, dorsal hollow nerve cord
postanal tail, a tail that extends beyond the
anus, at least during embryonic development
Vertebrates
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backbone (series of hollow bones) that replaces the
notochord
Head: skull and brain
Fish
1.
2.
3.
4.
Gills, to extract dissolved oxygen ________
vertebral column, skeleton made of either
bone or cartilage
single-loop blood _________ , blood is
pumped from the heart to the gills, to the
body, and then back to the heart
Types:
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Chondrichthyes
 Ex: sharks and rays
 first jawed fishes
 flexible, cartilaginous skeleton
Bony fish
 internal skeleton of bone
 _____ ______, gas-filled sac to regulate
buoyant density
 most diverse of all vertebrates
Amphibians
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direct descendant of fishes
Ex: Frogs, Salamanders
Moist skin for __________
Legs
Lungs and cutaneous respiration
pulmonary veins, returns oxygenated
blood from the lungs to the heart for
repumping
partially _______ heart, helps to prevent
oxygenated blood deoxygenated blood
Reptiles
• Ex: Turtles, lizards, snakes, crocodile, alligators
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amniotic egg: watertight eggs protected from drying out
with food source (yolk) comprised of four layers of membranes
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Chorion: O2 to enter but not the exit of H2O
yolk sac: connects to the gut of the embryo and delivers food
Allantois: accumulates wastes from the embryo
Amnion: fluid-filled
dry skin to prevent ________ ________
Birds
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evolved from bipedal dinosaurs
lack teeth
vestigial tails
_________ eggs
reptilian scales on their feet and lower legs
____________ lightweight and adapted for flight
flight skeleton is firm for attaching flight muscles, the bones are
thin and hollow
Mammals
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middle ear with three bones that evolved from bones in the
reptile jaw
_____________________ in females to produce milk to
nurse the newborns
_________________ to provide nourishment to the young
while it is in the uterus
Endothermy which allows mammals to be active at any time
of the day or night and to ___________________
Heterodont dentition, different types of teeth are highly
specialized to match eating habits
Hair for insulation made up of dead cells filled with the
protein, keratin
horns, claws, fingenails made with keratin
1.
monotremes,
1.
2.
the only egg-laying mammals
Ex: duck-billed platypus and anteater
2. marsupials,
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young nursed in a marsupial pouch
Ex: __________
3. placental mammals,
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young develop in the uterus for a long
time while being nourished by a placenta
Ex:
Practice questions
1.
A)
B)
C)
D)
Which of the following characteristics is not seen in
the flatworms?
Cephalization
Mesoderm
specialization of digestive tract
bilateral symmetry
2. One difference between Nematoda (roundworms) and
Annelida (segmented worms) is the pseudocoel
develops between the mesoderm and the
_____________ in roundworms, and the coelom
develops in the _____________ in segmented
worms.
3. All fish species share all of the following characteristics except:
A) Gills
B) Jaws
C) endoskeleton with dorsal nerve cord
D) single loop circulatory system.
4. sharks and bony fish have evolved anatomical solutions to
increase swimming speed and maneuverability. Which of the
MAJOR modification found in bony fish? ___________
5.
6.
7.
Adaptations in reptiles that allow them to overcome
dehydration include ______, _________
Characteristics that evolved in birds to allow for flight include
________ AND _______
A characteristic unique to almost all mammals and no other
vertebrates is ___________