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AP Bio Animal Unit

animal characteristics
-multicellular heterotrophic eukaryotes
-no cell wall, cells held with collagen
-nerve and muscle tissue
-sexual reproduction
mitotic divisions after fertilization
hollow ball of cells formed by cleavage
forms the primitive gut (adult body parts will arise from these embryonic tissues in the gastrula)
germ layers
Three main layers that form the various tissues and organs of an animal body.
"blue" gives rise to the outer surface and sometimes nervous system
"yellow" lines the digestive tube (archenteron)
"red" forms muscles and many organs
no true tissue
Phylum Porifera
-loose federation of cells,
-no mesoderm, asymmetrical
-filter feeders
-water into pores into spongocoel exits osculum
-food filtered out by choanocytes
-most are hermaphrodites
large central cavity of the sponge
A large opening on a sponge through which filtered water is expelled
flagellated collar cells in sponges that filter food
true tissue
radial symmetry, diploplastic
have only 2 germ layers (ectoderm and endoderm)
Phylum Cnidaria
-(Eumetazoa, Radiata)
-hydra, jelly fish, sea anemonem coral
-gastrovascular cavity
-single opening for mouth/anus
-polyp and medusa form
-sexual and asexual reproduction
-muscles and nerves in simplest form
stinging capsules located in special cells called cnidocytes (on tentacles)
special cells with nematocysts
Phylum Ctenophora
-(Eumetazoa, Radiata)
-similar to Cnidaria
-comb jellies
-move by cilia fused into combs
no coelom (body cavity)
bilateral symmetry, triploblastic
mesoderm lined body cavity besides the digestive cavity
Phylum Platyhelminthes
-(Eumetazoa, Bilateria, Acoelomate)
-some free living, some parasitic
-some cephalization
-no body cavity
-mesoderm gives rise to more complex organs and true muscle tissue
-one opening digestive tract
concentration of sense organs and nerve cells at the front of an animal's body
triploblastic, body cavity but not completely enclosed by mesoderm
Phylum Rotifera
-(Eumetazoa, Bilateria, Pseudocoelomate)
-complete digestive tract (mouth and anus)
process in which an unfertilized egg develops into a new individual
Phylum Nematoda
-(Eumetazoa, Bilateria, Pseudocoelomate)
-round worms
-many free living, some parasitic
-hookworm, pinworm, Trichina
body cavity completely enclosed by mesoderm besides digestive cavity, triploblastic
spiral, determinate cleavage (cells have designated purpose right away), blastopore becomes mouth
Phylum Nemertea
-(Eumetazoa, Bilateria, Coelomate, Protostome)
-proboscis worms (ribbon worms)
-complete digestive tract
-closed circulatory system
-many evolved away from coelom
P. Bryozoa, P. Phoronida, P. Brachiopoda
-(Eumetazoa, Bilateria, Coelomate, Protostome)
-Lophophorate animals, have horse-shoe shaped fold with cilia surrounding the mouth
-evolved into filter feeders
-complete digestive tract
Phylum Mollusca
-(Eumetazoa, Bilateria, Coelomate, Protostome)
-snails, slugs, oysters, octopus
-separate sexes or hermaphrodites (snails)
-muscular foot
-visceral mass
-(3 classes to remember)
fold of tissue that covers visceral mass, often secretes shell
visceral mass
contains organs
rasping organ that scrapes up food
Class Gastropoda
-stomach foot
Class Bivalva
-2 shells
Class Cephalopoda
-head foot
-internal shell
Phylum Annelida
-(Eumetazoa, Bilateria, Coelomate, Protostome)
-segmented worms (earthworm)
-closed circulatory system
-cerebral ganglia & nerve cords
each segment has 2 to excrete metabolic waste
Phylum Arthropoda
-(Eumetazoa, Bilateria, Coelomate, Protostome)
-regional segmentation
-jointed appendages
-extensive cephalization
-open circulatory system
-internal fertilization
-(5 classes to remember)
Class Arachnida
-scorpians, spiders, ticks, mites
-cephalothorax with 6 pairs appendages
-2 pr chelicerae (sensing), 4 pair walking leg
Class Diplopoda
-2 pr. leg per segment
-eat decaying matter
Class Chilopoda
-1 pr. leg per segment
Class Insecta
-wings are extension of cuticle
-most successful terrestrial
-tracheal system for gas exchange
-maliphigian tubules for excretion of metabolic waste
-cerebral ganglium
-many undergo complete or incomplete metamorphosis
Class Crustacea
-crabs, lobsters, shrimp
-2 pr. antennae
-appendages on thorax and abdomen
radial, indeterminate cleavage (cells function not immediately determined), blastopore becomes anus
Phylum Echinodermata
-(Eumetazoa, Bilateria, Coelomate, Deuterostomes)
-sea stars, sea urchins
-water vascular system
-tube feet (for locomotion)
-external fertilization
water vascular system
network of hydraulic canals
Phylum Chordata
-(Eumetazoa, Bilateria, Coelomate, Deuterostome)
-dorsal, hollow nerve cord
-pharyngeal gill slits
-muscular, post-anal tail
flexible rod between digestive and nerve cords
dorsal, hollow nerve cord
from ectoderm rolling into a tube
Subphylum Urochordata
-Phylum Chordata
-sessile as adult
Subphylum Cephalochordata
-Phylum Chordata
-may have evolved from paedogenesis of Urochordata
Subphylum Vertebrata
-Phylum Chordata
-neural crest
-high degree cephalization
-vertebral column and cranium
-closed circulatory system
neural crest
embryonic cells forming on dorsal part of neural tube: go to make up bones and cartilage of brain case (skull)
Class Agnatha
-jawless fish
-lampreys and hagfish
-considered a superclass divided into class myxini (hagfish) and class cephalaspidomorphii (lampreys)
Superclass Gnathostomata
- includes fish, reptiles, birds, mammals, and amphibians
-jaws work up and down
-2 sets of paired appendages
Class Chondrichthyes
-cartilage fish
-sharks, skates, rays
-lateral line system
-internal fertilization
-oviparous, ovoviviparious, and viviparous
-have to move to keep water over gills
-2 chambered heart
lateral line system
row of tiny organs sensitive to changes in water pressure, help detect sound waves and splashing
eggs hatch outside body
eggs hatch inside uterus after being nourished by yolk
give birth to live young that receive nourishment from mother's blood
Class Osteichthyes
-bony fish
-common fish are these
-lateral line system
-operculum, protective flap over gills
-can breathe while stationary
-swim bladder (air sac maintaining buoyancy)
-oviparous, external fertilization
-2 chambered heart
-(2 subclasses to remember)
Subclass Actinopterygii
-ray finned fish, most fish known today
-bass, salmon, perch, etc.
Subclass Sarcopterygii
-lobe-finned fish/lung fishes
-not many left, once dominant predator in shallow water
-can gulp air into lungs when ponds dry up
-gave rise to amphibians
Class Amphibia
-close ties with water
-must lay eggs in water or moist environment
-eggs are no shelled and dry out easily
-need moist skin to absorb oxygen from air
-external ferilization
-3 chambered heart
-(3 orders to remember)
Order Urodela
Order Anura
-frogs, toads
Order Apoda
Class Reptilia
-amniotic egg (can be laid on land & dry places)
-breathe only through lungs
-keratinized skin
-internal fertilization
-oviparous, some viviparous
-3 almost 4 chambered heart
-(3 orders to remember)
Order Chelonia
Order Squamata
-lizards and snakes
Order Crocodilia
-crocodiles and alligators
keratinized skin
prevents dehydration
absorb external heat rather than generating their own (need less energy than mammals)
Class Aves
-closest relative to dinos
-amniotic egg
-hollow bones
-one ovary, toothless
-4 chambered heart
-internal fertilization
-keeled sternum
-feathers (light & strong, probably evolved from endothermy originally for insulation)
amniotic egg
shelled egg that retains water and can be laid on land or dry places
keeled sternum
anchors huge pectoral muscles necessary for flight
they control their body temperature internally through metabolism
Class Mammalia
-mammary glands (millk)
-Endothermic (maintained by hair & fat)
-4 chambered heart
-internal fertilization
-viviparous (besides monotremes)
-differentiation of teeth
-include eutherians, monotremes, and marsupials
placental mammals
-extraembyronic membranes and uterine wall combine to form placenta that nourishes embryo
-longer pregnancy
egg laying mammals
-duck billed platypus and spiny anteater
-young born early and small
-must crawl to pouch where they nurse and complete development
Order Primata
-early ones arboreal, insectivorous, nocturnal
-gave rise to binocular vision
-nails instead of claws, grasping hands
-earliest were presimians (premonkeys)
-probably gave rise to anthropoids (monkeys, humans, apes)
-new & old world monkeys
New World Monkeys
-South America
Old World Monkeys
-some arboreal
-some on ground
-no tails
-Africa, Asia
some of oldest hominids (4 mill years ago)
best skeleton of Australopithecus afarensis, species remained unchanged for 1 million years until over taken
Homo habilis (handy man)
-had larger brain
-used tools
-arose 2.5 millions years ago
-say separate line from Australopithecenes
Homo erectus
-java man & beijing man
-found inside and outside of Africa
-migration because of meet eating?
-1.8 million years ago to 250,00 years ago
-larger brains
-include Neanderthal Man?? (130,000 - 35,000 years ago)
-abstract thought (burial rituals)
Homo sapiens (wise man)
-modern man
-multiregional and monogenesis models
Multiregional model
modern humans arose in parallel in several areas around the world
Monogenesis model
modern humans arose in africa only from H. erectus and spread to other areas eventually replacing other hominids that had migrated earlier
Evidence of models for modern man
-only Africa contains fossils of ALL proposed stages of hominid evolution
-Neanderthal s and H. sapiens fossils coexisted and did not interbreed for 40,000 years in Israel
-mtDNA traced all modern humans back to Africa 200,000 years ago