Ch 34

Question 1

Notochord

Answer 1

• longitudinal flexible rob between digestuve tube and nerve cord
  -provides skeletal support
  -adults retains only remnants
  -

Question 2

Key charateristics of chordates

Answer 2

-notochord
-dorsal, hollow nerve cord
-pharyngeal slits
-muscular post anail tail
-some only have these traits during embryonic development
-in most, tail is greatly reduced during embryonic development
-common for genes of heart/throid to be associated

Question 3

nerve cord in chordate

Answer 3

-develops from a plate of ectoderm and rolls into a tube dorsal to the notochord
-develops into central nervous system

Question 4

Tunicates

Answer 4

-invertebrates
-urochordata
-sea squirts
-more closely related to other chordates than lancelets
-salps, …
-most resemble chordates at larval stage (only few minutes)
-adult: draws in water thorught incurrent siphon (filtering food particles)
-shoot water through their excurrent siphon
-one cluster of Hox gene

Question 5

pharyngeal cleft

Answer 5

-in most chordates, it develops into slits that open to outside of body
-aquatic craniates: evolves into gill slits

Question 6

lancelets

Answer 6

-cephalochordate
–marine suspension feeders
-notochord
-dorsal hollow nerve cord
-pharyngeal slits
-postanal tail, endo style
-may have resembles ancestral chordates
-Hox gene expressed in simple nerve cord tip
-one cluster of Hox gene

Question 7

craniates

Answer 7

-chordates that have a head
-2 clusters of Hox genes
-neural crest
-higher metabolism and more musculer than tunicates and lancelets
-skull, brain, eyes and other sensory organs
-heart w/ at least 2 chambers, red bloodcells, and kidneys
-fossils from Cambrian explosion document transition in craniates
-more advanced chordate: Myllokunmingia
-most primitive: Haikouella (3cm, brain, eyes, muscular segments BUT no skull)
(whole groups of animals, isnt just one type)
-most basal group is Myxini (hag fishes)

Question 8

Hagfishes

Answer 8

-Myxini
-most basal group of craniates
-cartiligous skull and axial rod
-lack jaws and certebrae
-small brain, eyes, ears , tooth like formtaions
-marine , bottom dwelling scavnergrs

Question 9

Lamprey

Answer 9

-petromyzontida
-oldest lving lineage of vertebrates
-jawless vertebrates that feed by clmaping their mouth onto fish
-marine and freshwater
-cartiligous segments surrounding notochord

Question 10

Conodonts

Answer 10

-first vertebrates w/ minerlaized skeltal elements in motuh and pharynx

Question 11

Gnathostoms

Answer 11

-craniata with jaws (Chondrichthyes, actinopterygii, sarcopterygii, amphibia, mammalia, lepidosauria, testudines, crocodilia, aves)
-duplication in Hox gene
-enlagrd forebrain assoictaed w/ enhanced smell and vision
-aqautic: lateral line system (sensitive to vibrations)
-clade
-most are oviparous

Question 12

PLacoderms

Answer 12

-earliesr gnathostomes
-armored vertebvrates
-Ordovician, 450 millions years ago

Question 13

Chondrichthyans

Answer 13

-skelton composed primarly of cartilage
-largest/most diverse group
-sharks , rays, skates

Question 14

Sharks

Answer 14

-streamlined body
-swift swimmers
-largest are suspension feeders, most are carnivores
-short digestive track
-acute sense (ability to detect electrical fields)
-eggs ferilized internally
-embryo develops in 3 diff. eays: oviparous, ovovivparous, and viviparous

Question 15

oviparous

m

Answer 15

-eggs hatch outsude moms body

Question 16

ovoviviparous

Answer 16

-embryo develops within uterus and is noursihed by egg yolk

Question 17

viviparous

Answer 17

-shark fertilization
-embryo develops within uterus and is nourshied through yolk sac placenta from moms bloood

Question 18

osteichthyans

Answer 18

–most have bony endo skeleton
-bony fish and tetrapods
-aquatic: we call fishes
-in clade gnathostomes

Question 19

operculum

Answer 19

-protects gills when drawing water

Question 20

swim bladder

Answer 20

-how fishes control bouyancy
-air sac

Question 21

Ray-finned fishes

Answer 21

-Actinoptergii
-originated from Silurian (444-416 million years ago)
-long, flexible ray protect fins and modify maneuvering, defense, and other functions

Question 22

Lobe-fins

Answer 22

-sarcopterygii
-have muscular pelvis and pectoral fins
-originated in Silurian period
-3 lineages survived: lung fish, coelacanths, tetrapods
-one of most significant event: fins on some evolved into limbs/feet of tetrapods

Question 23

Coelacanths

Answer 23

-thought to have been extinct, but found in South Afriva in 1938

Question 24

tetrapods

Answer 24

-gnathostomes
-four limbs, feet w/ digits
-neck
-fusion of pelvic girdle
-absence of gills
-ears for detecting airborne sounds
-first appeared 365 million years ago
-Tikataalik: fishapod, fish and tetrapod characteristics (most likely could prop itself up but not walk)

Question 25

Amphibians

Answer 25

-about 6150 species
-tetrapods
-salamanders
-frogs
-both land/water
-moist skin that complements lungs in gas exchnage
-some have lungs
-ferilization external (require moist environment)
-pop. has been declining (disease, habitate loss, climate change, pollution)

Question 26

Amniotes

Answer 26

-reptiles, birds and mammals
-members protect their embryos with amniotic sac
-amniotic eggs of most reptiles and some mammals have a shell
-relatively impermeable skin
-ability to use rib cage to ventilate lungs

Question 27

early amniotes

Answer 27

-amphibians and amniotes split from common ancestpr 350 million years ago
-more tolerant of dry conditons than early tetrapods

Question 28

reptiles

Answer 28

-tuataras, lizards, snakes, turtles, crocodilians, birds, and some extinct groups
-scales that create waterproof barriar
-lay shelled eggs on land
-ectothermic : absorbing external heat
-birds are endothermic: capable of keeping body warm thorugh metabolism

Question 29

parareptiles

Answer 29

-mostly large stocky quadrupedal herbivores
-first major group to emerge from carboniferous period
-as these were declining, diapsids were diversifying

Question 30

diapsids

Answer 30

2 lienages: lepidosaurs and archosaur

Question 31

archosaur

Answer 31

-pterosaurs: first tetrapods to exhibit flight + theropods
-crocodilians
-dinosaurs

Question 32

theropods

Answer 32

-where bird descended from
-bipedal carnivores

Question 33

lepidosaurs

Answer 33

-living species : tuataras, squamates(lizards and snakes)
-lizards most numerous/diverse reptiles, apart from birds
-snakes: carnivores, evolved from lizards

Question 34

turtles

Answer 34

-boxlike shell made of upper/lower shields fused to vertebrae clavicles and ribs
-some have adapted to deserts, others live in ponds or rievrs

Question 35

crocodilians

Answer 35

-alligators and crocodiles
-belong to archosaur lineage
-back to late Triassic

Question 36

birds

Answer 36

-archosaurs
-adaptations for flight: wings made of keratin, lack of uninary bladder, females have on ovary, small gonads, loss of teeth
-flight: enhances hunting/scavenging, escape from predators, migration/ requires energy, acute vision, fine muscle control

Question 37

living birds

Answer 37

-belong to clade Neornithes
flightless: ratites, penguins, and certain species of rails, ducks, and pigeons

Question 38

origin of birds

Answer 38

-probably decsended frpm theropods(carnivorous dinosaurs)
- feathers: evolved for insultaion, camouflage, or courtship; gain lift when jumping, gain traction up hills, glide from trees
- 150 million years ago, feathered tetrapods evolved to birds
- Archaeopteryx: oldest known bird

Question 39

Mammals

Answer 39

-amniotes
-hair and produce milk
-more than 5,300 species
-mammary glands
-high metabolic rate due to endothermy
-larger brain
-differentiated teeth
-evolved from synapsids
-significnat adaptive radiation until after Cretaceous
-by Cretaceous, 3 living lineages emerged: monotremes, marsupials, and eutherians

Question 40

Monotremes

Answer 40

-small group of egg-laying mammals
echidnas and platypus

Question 41

Marsupial

Answer 41

-opossums, kangaroos, and koalas
-embryo develops in placenta of moms uterus
-born very in early in development
-completes development in maternal pouch (marsupium)
-bandicoot: pouch on rear
-convergent evolution caused diveristy that resemble eutherians in world

Question 42

eutherians

Answer 42

-more complex placenta
-complete development in uterus
-conflicting data on molecular and morphological dates on diversification
-whales, elephants, humans, dogs, cattle, etc

Question 43

primates

Answer 43

-humans are part of group
-hands/feet for grasping, flat nails
-large brain
-small jaw
-forward lookng eyes
-complex social behvaior
-opposable thumb
-living: lemurs, lorises, pottos, tarsiers, anthropoids (monkeys and apes)

Question 44

new world monkeys

Answer 44

-tail that can hang on to something
-south america
-appeared about 25 million years ago
-underwent seperate adaptive radition than old world

Question 45

old world monkey

Answer 45

-first monkeys evolved in Old world
-Africa and asia

Question 46

apes

Answer 46

-gibbons, orangutans, gorillas chimpanzees, bonobos, humans
-diverged from old world monkeys (20-25 million years ago)

Question 47

Homo sapians

Answer 47

-showed up about 200,000 years ago
-upright posture, bipedal locomotion
-larger brain (langauge, artistic expression, symbolic thought, use of compex tools)
-reduced jawbones/muscles
-shorter digestive tract
-human and chimpanzee are 99% identical
-descended from African ancestors
-oldest fossil outsude Afruca date back to 115,000 years (from middle east)
-humans first arrived to New World about 15,000 years ago

Question 48

Hominins

Answer 48

-more closely related to humans than chimpanzees
-20 species of extinct hominins
-early hominns: originated in Africa 6-7 million years ago (small brains and incrasing bipedalism)

Question 49

Austraopiths

Answer 49

-paraphyletic assemblahe of hominins living between 4-2 million years agi
-Australopithecus afarensis walked fully erect

Question 50

bipedalism

Answer 50

-walking on 2 feet
-hominins began to walk long distance on 2 legs
-1.9 million years ago

Question 51

tool use

Answer 51

oldest evidence of tool use: cut marks on animal bones
-2.5 million years ago

Question 52

Homo habilis

Answer 52

-earliest fossils
-2.4-1.6 million years
-usage of stone tools: called handy man

Question 53

Homo ergaster

Answer 53

first fully bipedal large brained hominid
-1.9-1.5 million years ago
-siginificant decrease in sexual dimorphism

Question 54

Homo erectus

Answer 54

-Africa 1.8 million years ago
-first to leave Africa

Question 55

Neanderthals

Answer 55

-Europe 350,000-28,000 years ago
-thick boned w/ larger brain
-buried their dead
-made hunting tools
-debate between exact exchange between genes for neanderthals and Homo sapians

Question 56

Homo floresiensis

Answer 56

-18,000 year old fossils found in 2004
-small hominin

Question 57

Chordata

Answer 57

-chordates
-bilaterian animals
comprise all vertebrates and 2 groups of invertebrates and cephalochordates

Question 58

functions of pharyngeal slits

Answer 58

-suspension feeding strcuture in invertebrate chordates
-gas exchnage in vertebrates
-develop into parts of the ear, head, neck in tetrapods

Question 59

neural crest

Answer 59

-collection of cells near the dorsal margins of closing neural tube in embryo
-gives rise to some of bones and cartilage in skull

Question 60

three main groups of primates

Answer 60

-lemurs, lorises and pottos
-tarsiers
-anthropids (monkeys and apes)

Question 61

Distinguishing characters between humans and other apes

Answer 61

-humans have larger brains
-humans not covered in thick hair
-human arms are relatively weaker than other ape arms
-humans have more complex verbal communication