Lektion 3 - Vertebrate Flashcards
What is a major difference between vertebrates and invertebrates?
Where the central nervous system is located. In protosomes it goes across the digestive system which it does not do for vertebrates.
What does it mean for vertebrates to be deuterostomes?
they develop an anus before a mouth
Enchinoderms properties?
Tagghudingar (sjöstjärna)
- pentaradiate symmetry
- only mouth
- endoskeleton
Hemichordates properties?
- gills lits
- low rate of genome evolution
What groups make up chordates?
Tunicates, Cephaliochordates
Vertebrates
What are the chordates four main charachteristics?
1) notochord
2) neutral tube
3) gill slits
4) post-anal tail
what does every branchial (gill) arch have?
- one nerve
- one cartilage
- one artery
Cephalochordates properties?
- filter feeding
- gill slits
- very conservative genome (no gene losses)
Tunicates properties?
- filter feeders
- very derived genomically
what are vertebrates?
ryggradsdjur
What are the trends in the evolution of vertebrates?
- shift from notochord to vertebral coloumn
- nerve cors expanded into brain
- evolution of jaws
- paired fins evolved, gave rise to limbs
What are the classical classes of vertebrates?
- jawless fishes
- cartilage fishes
- ray-finned fishes
- mammals
- reptiles
-birds
What are the key fish charachteristics? (6 st)
- Vertebral coloumn
- jaws
- gills
- swim bladder
- single loop blood circulation
- fish body is covered with scales and bony plates.
what is the function of a swim bladder?
A gas filled organ that contributes to the buouancy for many bony fishes (not cartilage fishes)
charachteristics for amphibians? (4st)
(frogs, toads, salamanders, newts, caecilians)
- legs (if not lost)
- Lungs (gills to delicate)
- Circulation evolved (high oxygen demand when move on land)
- Reproduction in water
What charachterizes birds? (7st)
- filght ability
- feathers
- skeleton
- charachteristic brest bone
- wishbone (joined collarbone)
- beak (no teeth)
- rudimentary tail
What are the three groups of mammals?
1) monotremes (lay eggs with shells, the female lacks well developed nipples. ex näbbdjur)
2) marsupials (form a short-lived placenta from the chorion just before birth, pouch bearing)
3) placentals
What are 6 synapomorphies of mammals?
1) hair (insulation, camouflage, sensory)
2) mammary glands and milk
3) endothermic
4) placenta
5) effective breathing
6)different adaptations of teeth
What is endothermy and why is it beneficial?
it means the animal produces its own heat which requires more energy. (found in mammals and birds).
Cools off by sweating, panting etc
What is ectotherm and why is it benefical?
animals that have a body temp that depends on the temperature around them. Requires less energy (does not nead to heat themself up). Good for warm climates, cold climates slow them down.
What makes a good model organism?
small size
fast sexual maturity (more convinient in a lab)
What are some common model animals used in labs?
- Nematode worm
- C. elegans
- Fruit fly
- Zebrafish
- Toad
- Mouse
