What is a vertebrate? Flashcards
List some vertebrate innovations
- bony skeleton
- neural crest cells
Describe bone
- a living tissue
- collagen fibres plus hydroxyapatite
hydroxyapatite
calcium phosphate crystals
Describe the bone cells
- osteoblast (makes bone)
- osteoclast (breaks down bone)
- osteocytes (strain and crack sensors)
Describe a vertebrate embryo
- dorsal hollow nerve cord
- skin
- notochord
- gut
- somites
- lateral plate mesoderm
somites
- segmented mesoderm
- contains sclerotome
lateral plate mesoderm
unsegmented mesoderm
sclerotome
forms bone
Where do neural crest cells come from?
- sensory nerves
- pigment cells
- motor and sensory nerves in the gut
- autonomic nervous system
- bone and cartilage in the head
What does the autonomic nervous system control?
heart rate, breathing
Describe the skull
- most made from Neural Crest-derived bone
- the ‘base’ of the skull is the first few somites
Describe vertebrate complex factors
- sense organs of the head (olfactory, optic and otic)
- much more forebrain
- clear midbrain
- segmented hindbrain
What does the midbrain do?
optic lobes
What does the hindbrain do?
touch sense and gill skeleton
Describe the adaptations of vertebrates
- skeleton: efficient locomotion
- dominant head: big brain and effective sense organs protected and armoured
What did vertebrate innovation allow?
early vertebrates to evolve into active swimming and hunting marine predators
List the 3 main evolutionary lineages of vertebrates
- Chondrichthyans
- Actinopterygian
- Sarcopterygians
Describe the Chondrichthyans
- cartilagenous fish
- sharks
- rays
Describe the Actinopterygians
- ray-finned fish
- teleosts
Describe the Sarcopterygians
- lobe-finned fish
- tetrapods
What are the two minor vertebrate groups?
- lampreys
- hagfish
What separates the lampreys and hagfish from the actinopterygii, sarcopterygii and Chondrichthyes?
- jaws
- paired fins
Reptiles
- amniotes minus birds and mammals
- paraphyletic
Who uses an amniotic egg?
reptiles
Describe lampreys
- no jaws
- no paired fins
- no true bone
- circular, rasping mouth
- most spawn in rivers then
migrate to sea
Give a non-migratory lamprey
Brook Lamprey (UK)
Describe hagfish
- no jaws
- no paired fins
- no true bone
- horizontal piercing mouthparts
- scavenge dead fish
- marine
- slime
Describe hagfish morphology
- tentacles
- pharyngeal slits
- mucous glands
Describe hagfish slime secretion
- vesicles with ‘mucin’
- long-coiled proteins that tangle the slime together
