9: amniotes (vertebrates)

what is the significance of the amniotic egg?

it allowed animals to complete sexual reproduction w/out the presence of standing water

amniotic egg includes?

amnion, allantois, chorion, yolk sac, amniotic cavity, embryo, yolk, albumen, and the shell

amnion fxn

cushions the embryo against electric shock in a watery amniotic sac

allantois fxn

waste disposal/gas exchange

chorion fxn

gas exchange

yolk sac fxn

delivers nutrients

albumen stores…

a lot of water and has protein

yolk is made of…

nutrients

amniotic cavity contains

amniotic fluid

extramebtyonic membranes sustain…

embryo w/little water loss

porous egg shell protects and reduces…

dehydration allowing O2/CO2 exchange

what varies of the egg-shells rigidity?

CaCO3

what MUST fertilization be before the egg shell is made?

internal

temporal fenestrae of an anapsids, synapsids, and synapsids allows …

muscles to expand and lengthen

the 1st amniotes evolved from what during what period?

tetrapod ancestors 340 MYA during the Carboniferous period

mammals come from?

therapsids

therapsids come from?

synapsids

lepidosaurs and archosaurs come from?

diapsids

where did diapsids and anapsids come from?

sauropsids

where did synapsids and saurposids come from?

early amniotes

lepidosaurs

modern lizards, snakes, and tautaras

archosaurs

modern crocodiles, alligators, and birds

anapsids

no opening behind skull

synapsids

1 opening behind skull

diapsids

2 opening behind skull

reptiles are classified as…

tetrapods including snakes and legless lizards which descended from 4 limbed ancestors

what do reptiles skin contain?

scaly skin containing keratins and waxy lipids which helped permit them to live on land

what can reptiles NOT use their skin for?

respiration so they breathe w/lungs

what pressure breathing do reptiles use?

negative expanding their ribcage which is more efficient than gulping air by fish and amphibians (positive)

lizards and snakes are endotherms or ectotherms ?

ectotherms

birds are endotherms or ectotherms?

endotherms

expanding rig cage equals higher…

volume and lower pressure

what is the origin of birds?

they diverged from a group of bipedal, feathered dinosaurs during the late Mesozoic Era; Archosaurs

what is the earliest known bird w/many dinosaur characters ?

Archaeopteryx

did any extant bird descend from the Archaeopteryx lineage?

no

what are the 7 adaptations for flight?

1. modified forelimbs

2. lightweight skeleton

3. stubby feathered tail

4. no teeth

5. 4-chambered heart

6. efficient respiration system

7. urogenital adaptations

how were birds forelimbs modified?

into wings w/ keratins contour feathers that provide lift and make a flexible strong surface

what characteristics describe birds lightweight skeleton?

it’s strong, provides a decrease in # of bones, and pneumatization of bones (hollow bones)

what’s the purpose of a stubby feathered tail?

flight maneuvers

what’s the purpose of birds having no teeth?

they have a beak of keratin over bone

what’s the purpose of a 4-chambered heart?

to efficiently deliver oxygenated blood to the body and re-oxygenate blood in the lungs

what’s an advantage of a highly efficient respiration system w/air sacs?

it allows negative-pressure breathing that permit a unidirectional flow of air through the lungs

what are the 4 urogenital adaptations of birds?

1. no bladder or urethra (cloaca)

2. only 1 ovary

3. sex organs functional during breeding season

4. muscular gizzard grinds up food