T17 Flashcards
SHARED TRAITS IN CHORDATA - in the deutrostomia group, triploblastic
notochord - a cartilage char running down the body between the digestive tract and nerve cord
dorsal hollow nerve cord
post anal tail
pharyngeal slits or clefs - can develop into jaws
these 4 traits can be lost or repurposed throughout a lifetime in this group
vertebrates shared traits
cranium and neural crests - a line formed to become the neural trube
HOX genes - development genes where features develop
multi-chambered heart - allows for directional flow of blood
cephalochordates
technically invertebrates
- filter feeders - uses mucus in pharyngeal slits to capture prey
- gaseous exchange through body surface
Urochordata
invertebrates
- as adults they lose the 4 features of chordates expect pharyngeal slits
- well developed closed circulatory system
- solitary or clonial
- marine filter feeders
cyclostomes
chordates - vertebrates
- incude jawless fish
have small or reduced vertbreae
GNATHOSTOMATA
sharks, reptiles, fishes
- jaw dervived from skeletal rod
- lots of HOX genes
- adaptive immune system
- enlarged fore brain
lateral line organs in aquatic - allow to sense movement
Chondrichthyans
skeleton made out of cartilage
- tooth like scales called dernal denticles
- 5-7 gill pairs from respiration
osteichthies
where lungs or lung derived animals begins
- bony fish, ossified endoskeletons
2 ways to classify:
ray finned
- clasistia, chondrostei, holostei and toelost
lobe fin
actinistia
closely related to tetrapods and lobe fines
dipnoi
fish that breath through lungs or gills
retain their notochord and cartilage brain case
tetrapodes
4 legged animals
amphibians - tetrapods
mainly external fertilisation
caecilians - legless
moist habitat as skin is used for GE
amniota
amniotic egg is a hardshell egg with water in to stay moist
rib cage and neck for lungs
mammals shared traits
mammary glands- produce milk
larger brains and skulls - synapsid skulls
an extended period of parental care
well developed circulatory system - 4 chambers
specialised teeth
20 extant orders for mammals
cutaneous animal breathing
use skin for gaseous exchange
- use a system of capillaries beneath skin to move oxygen and carbon dioxide
cost very little energy due to no ventiliation
however
need skin to be moist and need a low sa:v