Chapter 27 Flashcards
What are the 3 chordate types
Lancelets, tunicates and vertebrates
Notochord provides
Support and replaced Skelton
The nerve cord…
Develops into the brain and spinal cord
The 3 key features of a chrodates
Notochord, nerve cord and post anal tail and pharyngeal gill slips
All vertebrae’s have
Clusters of hox genes,
A vertebral column
Cranium
Endoskeleton
Diverse internal organs
Importance of pharyngeal Gil slits
Used to take in oxygen
What are the 2 cyclostomes
Hagfish and lampreys
Hagfish vs lampreys
Hagfish have notochord and lampreys posses a rudimentary vertebral column
Gnathstomes are
Animals with jaws and enlarged brain
Chnondrivhthyes examples
Sharks, skates and rays q
Chondrichthyes are also known as
Cartilaginous fishes
How does water move through sharks ?
Through their mouth and across gills
Chondrichthyes teeth are
Not set into their jaw
Oviparity
Lays eggs
Ovoiparity
Eggs retained in female, no placenta
Vivparity
Eggs develop in uterus, nourished by placenta
Ostechthyes are
Bony fish
Key features of a osteichthyes
Protective operculum,
Swim bladder
Bony skeleton
How do most osteichthyes reproduce
External fertilization
How do ray finned fish move
Muscles through their body they are supported by thin, bonds flexible rays
Actinopterygii are
Rey finned fish
Actinopterygii are ____ group
Monophyletic
Sarcopterygii are supported by skeletal extension
Moved by muscles within the fins
When lobe fins developed into legs they became
Tetrapods and then amphibians
Benefits of tetrapod/amphibians
Avoidance to predators and new source of food
What can be blamed from changes of
The hox genes
What happened to most amphibians
They return to water to reproduce
Who can absorb oxygen across the skin
Tetrapods
3 orders of amphibians
Anura, Apoda, urodrela
Anura’s are
Frogs and toads whose prime legs can be used for jumping or swimming with no tail
Apoda’s are
Wormlike caecilians that are nearly blind and legless
Ureodela’s are
Salamanders with legs, long tail and elongated body
Amniotic eggs are
Evolution of a shelled eggs sheltered the embryo from desiccation on land
With an amniotic egg
Reproduction was no longer tied to water
What protects the embryo
Amnion
What is the shell imperable to
Water
Where does gas exchange in the emrbryo And encloses waste
Allantois
What encloses nutrients
Yolk sac
Mammals reproduction
Viviparous
Testudines are
Turtles
Squatmata characteristic
Kinetic skull and joints are mobile
Fishes have ___ chamber
2
Amphibians have ___ chamber and __ loop
3 and 2
Turtles characteristics
Long lived
Lack teeth
Lay eggs on land
Birds, cordillera and mammals have ___ chambers
4
Reptiles have ___ chambers
3
All aves have
Feathers
Birds unique features
Feathers
Air sacs (9)
Reduction of organs
Lightweight bones
Reptiles; Aves;
Birds
Avian characteristics
Excellent vision, warm body temp
Mammals emerged from the
Mid Triassic period, from aminotes
Prototheria
Order monotremata and lay eggs
Mammals characteristics
Mammary glands
Hair
Speciliazed teeth
Englarged skull
The 2 mammalian order
Prototheria and theria
