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60 Cards in this Set

  • Front
  • Back
phylum Chordata includes which subphyla
Urochordata (tunicates), Cephalochordata (lancelets), and Vertebrata (fishes, amphibians, reptiles, birds, and mammals)
Traditional systematics (evolutionary systematics)
developed in an attempt to order and classify the large number of species being described.
ex. kingdom, phylum, class
phylogenetic systematics (cladistics)
scientists try to classify organisms based upon evolutionary relationships
the trees of evolution
the branches are always dichotomous with each branch representing divergence
a grouping that consists of an ancestral species and all of it's descendants
Archosauria include which animals?
include crocodiles and alligators, dinosaurs, and birds
Why might two systems generate different trees?
b/c scientsits rank the importance of the characteristics differently.
derived characters
newl acquired characters, distinct from ancestral characters
How can there still be different cladograms with same data?
it depends upon how the scientist weigh each parameter.
What are considered in constructing the tree? There are 5
ecology, behavior, physiology, morphology and DNA sequence
How does adaptation lead to function?
it enchances evolutionary fitness and that arose historically as a result of natural selection for its current biological role
refers to the number of species within a specific lineage (e.g. vertebrates, or primates, or the genus Homo)
refers to the range of anatomical structural variation (e.g. body shape, or brain complexity)
convergent evolution
fromation of structures that have similar function.
homologous evolution
eventual fomration of structures from similar developmental structures. final outcome may be drastically different in the organisms being examined.
What four characteristics set Chordata aprt from other phyla?
1. notochord
2. dorsal hollow nerve cord
3. pharyngeal gill slits
4. postanal tail

always found in embryo
What other feautres associates with chordate?
enlarged sense organs, closed circulatory system with a ventral heart, cartilaginous endoskeleton, and segmented striated muscles
When did Chordate first appear?
Cambrian period about 550 million years ago
What common characteristic is shared by all members of the chordata gropu?
semi-rigid, rod like structure of vacuolated cells acts as skeletal axis for support of the body. All chordates have notochord at some time during their life
What ancestral feautres did chordata inhereit?
3 germ layers, bilateral symmetry, well developed coelom, filter feeding, complete digestive tract, aand segmented body
Whats the subphylum of Chordata?
Urochordata - filter feeding
tunicate larvae capable of reproducing
What is differenat about Vertebrates than Chordata
have same features except notochord is replaced by vertebrae. Another is the brain.
What other features do vertebrates have?
Heart, cranium, and lateral line system (sense pressure changes/movement in water)
What forms the unique endoskeleton of the vertebrates?
carnium, visceral arches, limb girdles, and four jointed appendages
When did the endoskeleton first appear?
500 million years ago Ordovician period
functions of fins
used for mtion, brakes, and tilting rudders
lateral line system
perceives water currents and vibration
suction feeding
draws water and prey in mouth for ingestion then goes to gills
oldest undisputed vertebrates-small, heavily armored jawless fish with an expanded armored head with typical sense organs and a gill chamber.
What has been the major driving force for evolution?
the JAW
What benefits does the jaw give?
take in large prey quickly, can penetrate well armored prey. incrase metabolism rates, increase growth and levels of activity
jawless fish
jawed fish
bottom dwellers, somewhat lethargic, scavengers in the adult state. resemble eel. larvae filter feeders.
name three classes that are jawed fishes
placoderms, Chondrichthyes and Osteichthyes
2 classes of gnathostomes
Chondrichthyes and Osteichthyes
name animals in Chondrichthyes
sharks, skates and rays.
When did Chondrichthyes appear?
450 million
8 general traits of chondrichtyes
1. body fusiform (spindle shaped)
2. ventral jaws with teeth from modified skin. loosely bound
3. skin with placoid sscales (denticles)
4. endoskeleton of cartilage; notochord persistent, vertebrae complete and separate
5. swim bladder absent; fatty acid in liver
6. respiration 5-7 gills
7. two-chambered heart
8. osmoregulation retention of nitrogenous wastes in blood
bony fish.
What major unique feature in all osteichthyans? two other major innovations?
ossified endoskeleton

lungs, and red bone marrow
ray-finned fish. (fish)
marlins, perch, tuna
initially what were swin bladders used for?
lobe-finned, or fleshy finned fish.
Why is sarcopterygia important ?
gave rise to first terrestrial vertebrates (tretrapods)
Name 2 examples of living sarcopterygia
coelacanth (Actinistia) and lungfish (Dipnoi)
when was first sarcopterygians known?
400 million years ago Devonian period
can live in either fresh or seawater
what are two main groups of tetrapods?
amphibia and amniota
Tetrapods unique features?
fingers and toes; interlocking, stiffend vertebral column, hinged well msucled limbs; loss of dorsal fins; head and shoulder separated by neck; tongue; nostrils open into mmouth, loss of lateral line system, and a three chambered heart
What three extant orders are there in Class Amphibia?
Urodela (newts and salamanders), anura (frogs and toads), and Gymnophiona (caecilians)
Where are Urodela found?
almost all temperate and tropical regions
smaller frogs
limbless, burrowing/aquatic amphibians. bodies elongate, sensory tentacles on their head, skull often fused into fairly solid capsul
vertebrates possess a true amniotic egg with a shell and three extra embryonic membranes (chorian, amnion, and allantois)
what are the three extraembryonic membranes?
chorion, amnion, allantois
What were the amniote scales composed of in the Amniota?