Deuterostomes Part 2 (Phylum Chordata) Flashcards
What symmetry do Chordates have?
bilateral
What body cavity do Chordates have?
true coelomates
What are the nearest relatives to Chordates?
Echinoderms
What characteristics do all Chordates have at some point in their life?
Nerve cord, notocord, pharyngeal slits, and postnatal tail
What is the nerve cord?
where neurons are located, transmits info from sensory organs to brain and other organs
What is the notochord?
rigid rod like structure that gives support, protects nerve cord (notochord located under the spine)
What are pharyngeal slits?
openings in the pharynx that extend to the outside environment, slits that could develop into gills for aquatic vertebrae animals
What are the subphylum of Chordates?
Urochordata, Cephalochordata, and Vertebrata
Which of the subphylum of Chordates are nonvertebrates?
Urochordata and Cephalochordata
What are the animals of Urochordata?
Tunicates
What are tunicates?
sea squirts
What do tunicates look like as larvae?
tadpole-like free-swimmers
What do tunicates look like as adults?
immobile filter-feeders
What do tunicate larvae eat?
do not feed
What happens when tunicates become adults?
lose their tail and notochord
What do adult tunicates secrete?
a tunic
What is a tunic made of?
a cellulose sac
What is the purpose of a tunic?
envelope that wraps around the Tunicate like a cloak
When do Tunicates have bilateral symmetry?
as larvae, as adults they have no symmetry
What circulatory system do Tunicates have?
closed
What animals are Cephalochordata?
Lancelets
When do Lancelets have notochord?
throughout their life
Do Lancelets have a distinguishable head?
no
How do Lancelets eat?
filter feeders
What is the closest relative to vertebrates?
Cephalochordata
Do Cephalochordata have eyes?
no but they have eye spots
What are Vertebrates?
chordates with a spinal column
How are Vertebrates distinguished from Non-vertebrates?
vertebral column and cranium
What is a vertebral column?
encloses and protects the dorsal nerve cord
What is the cranium?
a hard structure that encloses the brain
What is the cranium?
a hard structure that encloses the brain
What are skeletons of Vertebrates made of?
bone or cartilage
Why do vertebrates need a cranium?
as organisms get more complex in volume of brain, they need something to protect it
What is the largest group of Chordates?
Vertebrata
What does Gnathostomes mean?
have true jaws
What is the importance of the presence of jaws?
allows vertebrates to be larger and more powerful as it makes them more efficient feeders
What are the classes of Vertebrata?
- Agnatha
- Chondrichthyes
- Osteichthyes
- Amphibia
- Reptilia
- Aves
- Mammalia
What class of Vertebrata is not a Gnathostome?
Agnatha
What animals are Agnatha?
jawless fishes
What animals are Chondrichthyes?
cartilaginous fishes
What animals are Osteichthyes?
bony fishes
What animals are Amphibia?
amphibians
What animals are Reptilia?
reptiles
What animals are Aves?
birds
What animals are Mammalia?
mammals
What is the most diverse vertebrae group?
fishes
What characteristics do fishes have?
- vertebral column (except agnathans)
- jaws and paired appendages (except agnathans)
- internal gills
- single-loop blood circulation
What are paired appendages?
fins
What do paired appendages allow for?
sophisticated movement
What is a single-loop blood circulation?
closed circulatory system with a chambered heart
What does the chambered heart do?
responsible for pumping blood so gills can take in oxygen and bring to tissues
What are specific examples of animals that are Agnathans?
Hagfishes and Lamprey
What are hagfishes?
eel-like scavengers
What kind of skeleton do hagfishes have?
cartilage
Do hagfish have a notochord?
yes
Do hagfish have a vertebral column?
no
What are lamprey?
eel-like predators
Do lamprey have vertebrae?
some vertebral elements
Do lamprey have paired appendages?
no
What are specific examples of Chondrichthyes?
sharks, skates, and Rays
What is the endoskeleton of Chondrichthyes like?
entirely made of cartilage
How heavy are Chondrichthyes?
lighter body than boney fishes, buoyancy
Are Chondrichthyes flexible?
yes
What are shark’s sensory systems like?
well defined, can detect impulses from bodies of prey - electro magnitism
What do sharks have in their eyes?
tapetum lucidum
What is tapetum lucidum?
a reflective surface that allows them to see well in the dark
How do sharks give birth?
/
Vivaparous: live birth, some lay eggs
What skeleton do bony fishes have?
internal skeleton made completely of bone
What is the most species rich group of all vertebrates?
bony fishes
What are the 2 clades of Osteichythes?
ray-finned fishes and lobe-finned fishes
What do ray-finned fishes body structure?
- parallel bony rays that support and stiffen each fin
- no muscles within the fins, just at base
What evolved from lobe-finned fishes?
tetrapods
What is the body structure of lobe-finned fishes?
- paired fins that consist of a long fleshy muscular lobe
- supported by central co-jointed bones
What are the ancestors of amphibians?
lobe-finned fishes
What features do Osteichythes have?
- swim bladder
- gill cover
What is a swim bladder?
a gas-filled sac that allows bony fishes to regulate their buoyant density
What are gill covers also called?
operculum
What do gill covers do?
permit water pumping over gills
What does the name tetrapod mean?
4 foot
What are tetrapods?
adapted to terrestrial life
What appendages do tetrapods have?
bony appendages
Do tetrapods have lungs?
lungs in most
If a tetrapod doesn’t have lungs what does it do?
cutaneous respiration
What is cutaneous respiration?
breathe through skin on land/absorb oxygen by diffusion and must be in a moist environment
What is the purpose of the anatomy and physiology of tetrapods?
conserve water and support terrestrial movement
How do tetrapods have young?
- shelled eggs in some
- internal development of young in some
What makes up tetrapods?
- Amphibia
- Reptilia
- Aves
- Mammalia
What are amphibians?
damp skinned vertebrates
What was the first vertebrates to walk on land?
amphibians
Where must amphibians reproduce?
in water
What are amphibians tied to?
an aquatic lifestyle
How are amphibians similar to fishes?
they are anamniotes
What are anamniotes?
lack an amnion
What are amnions?
specialized embryonic membranes that are found in terrestrial vertebrates
What are the 3 types of modern amphibians?
- frogs and toads
- salamanders and newts
- caecilians
What order are frogs and toads?
Anura
What does the body of a frog look like?
smooth, moist skin and long legs
Where do frogs live?
in or near water, are out at night
What does the body of a toad look like?
bumpy, dry skin and short legs
Where do toads live?
dry environments, are out at night when moist or raining
How are Anura eggs fertilized?
externally
How do Anura eggs hatch?
into swimming tadpole larvae
What happens to tadpoles?
they undergo metamorphosis to turn into adults
How do frogs move?
jump
How do toads move?
hop
Do tadpoles have lungs?
they have gills that develop into lungs
Are frogs high or low to ground?
higher up because have sticky pads that increase surface area (?)
Are toads high or low to ground?
low to ground
What order are salamanders?
Caudata
What kind of body do salamanders have?
long bodies, tails and smooth, moist skin
Where do salamanders live?
moist places
How are Caudata eggs fertilized?
internally
What are Caudata larvae like?
similar to adults
What order are caecilians?
Apoda
What are caecilians?
tropical, burrowing amphibians
What does caecilians body like?
legless with small eyes and jaws with teeth
What is fertilizaiton like for Caudata?
internal
How do frogs breathe?
push air into lungs by using a pressure pump type of breathing
How do reptiles breathe?
use thoracic, expand volume in coelomic part of thorax
What are three key features of Reptilians?
- Amniotic Eggs
- Dry Skin
- Thoracic Breathing
What are amniotic eggs like?
watertight, allows diffusion of oxygen across shell prevents loss of water
What is the purpose of dry skin?
prevents water loss
What is the purpose of thoracic breathing?
increase lung capacity
What does the amniotic egg have?
4 membranes
What are amniotes?
reptiles, birds, and mammals
What are the 4 membranes of amniotic egg?
- chorion
- amnion
- yolk sac
- allantois
What is the function of chorion?
allows O2 entry
What is the function of amnion?
fluid-filled cavity
What is the function of yolk sac?
provides food, contains nourishments provided by the mother
What is the function of allantois?
excretes waste
How does amniotic egg embryo get oxygen?
oxygen diffuses into blood vessels and goes directly into embryo, before blood vessels develop chorion moves oxygen into amnion for diffusion
What are two important characteristics of reptiles?
- internal fertilization
- improved circulation
What is internal fertilization?
sperm fertilizes egg before protective membranes are formed as a way to ensure better chance of fertilization
What is improved circulation?
oxygen is provided to the body more efficiently
What type of circulatory system do reptiles have?
double loop
What is a double loop circulatory system?
one takes blood from heart and send to lungs and back to the heart, the other send to the rest of the body
Are reptiles endothermic or ectothermic?
ectothermic
What does ectothermic mean?
obtain heat from external sources; body is same temp as external environment
What is the temperature (food?) of reptiles tied to?
metabolism; lower metabolism means lower food requirement
What are the 4 Reptilia clades?
- Testudines
- Splenodontia
- Squamata
- Crocodilia
What animals are Testudines?
turtles and tortoises
What animals are Splenodontia?
tuataras
What animals are Squamata?
lizards and snakes
What animals are Crocodilia?
crocodiles, alligators, caimans, and gharials
Are amphibians endothermic or ectothermic?
ectothermic
What do reptiles do to increase metabolism?
bask in warm place if cold
What do reptiles do when it is too cold outside to gain heat?
hibernate
What shell shape do tortoises have?
dome-shaped
Why do tortoises have dome-shaped shell?
- dissipate excess heat
- bigger lung capacity
Do Testudines have teeth?
no but have sharp beak
What do marine turtles have to do?
return to land to lay eggs in sand or leaf litter for protection
What are the only reptiles with no teeth?
Testudines
What vertebrates have no teeth?
Aves and Testudines
How do tortoises and turtles struggle with copulation?
difficult due to shell shape but males have a concavity in their shell to allow for fit for mating
What are tuataras?
large lizard-like animals about half a meter long
Where are tuataras found?
only on islands near New Zealand
What unique feature do Tuataras have?
a partial third eye on the top of the head which allows sunlight to penetrate through skull into a portion of the brain to regulate circadian rhythm
Are there legless lizards?
yes
Where do crocodiles live?
near or in water in tropical and subtropical regions
When are crocodiles active?
night-nocturnal
Where are alligators found?
southern US and China
Where are caimans found?
central america
Where are gharials found?
India and Burma
What most closely resembles birds than other living reptiles?
crocodiles
How do crocodiles resemble birds?
- 4 chambered heart
- provide parental care
What does heterothermic/endothermic mean?
temperature of body relies on environment
What are the most diverse of all terrestrial vertebrates?
birds
Where are birds found?
diverse in habitat (can inhabit almost any habitat on earth)
What is the most numerous bird order?
Passeriformes
What kind of birds are Passeriformes?
song birds
What have birds retained?
many reptilian traits
What reptilian traits have birds retained?
amniotic eggs and scales on legs
What are amniotic eggs?
shelled eggs
What do bird red blood cells look like?
oval with nuclei
What other animals have red blood cells similar to birds?
reptiles, fish, and amphibians
What two major traits distinguish birds from reptiles?
- feathers
- flight skeleton
What is the purpose of feathers?
lift for flight and conserve heat
Are birds ectothermic or endothermic?
endothermic
What makes up a flight skeleton?
thing and hollow bones, many fused
What bones are fused in birds?
collarbone and keeled breastbone
Why do birds have hollow and fused bones?
to reduce body weight so they can fly
What type of shells do birds have?
hard because of calcium carbonate
What type of shells do reptiles have?
soft
What do birds do with offspring?
provide parental care which increases likelihood of offspring survival
Do reptiles provide care to offspring?
less than birds
What are birds the direct descendants of?
theropod dinosaurs
What structure do theropod dinosaurs have that birds still have today?
hip structure
What was the first known bird?
Archaeopteryx
What features did Archaeopteryx have?
- skull with teeth
- feathers on wings and tail
- forelimbs nearly identical to those of theropods
Why don’t birds have teeth?
teeth are heavy
Why do birds have hollow bones?
form an airspace
What are bird migratory patterns?
where birds travel far distances at high altitudes
Do birds have tailbones?
no
What are 3 characteristics of birds?
- efficient respiration
- efficient circulation
- endothermy
How do birds have efficient respiration?
air passes all the way through lungs in a single direction (“old air” never mixes with “new air” so have higher concentration of oxygen which means more ATP)
How do birds have efficient circulation?
- muscles receive fully oxygenated blood (4 chambered heart, no mixing of blood from tissues and heart so blood is fully oxygenated)
- rapid heartbeat (over 200 bpm)
What is endothermy?
body temperature permits higher metabolic rate
What other ways are birds different than reptiles?
- vast amount of songs
- visual colors that a lot of birds possess
Which vertebrate class has the fewest species?
Mammalia
What traits do mammalians have that distinguish them from all other vertebrates?
- hair
- mammary gland
What is hair?
long, keratin-rich filaments that extend from hair follicles
What is the function of hair?
insulation, camouflage, sensory structure (cat whiskers)
Who possesses mammary glands?
females
What is the function of mammary glands?
secrete milk
What is hair secreted from?
keratinocytes
What is colostrum?
the “first milk” which provides antibodies to the offspring
What are other notable features of mammals?
- endothermy
- placenta in some
What is the placenta?
specialized organ that brings fetal and maternal blood into close contact
Are most mammals placental?
yes
What does endothermy mean?
generate own heat
What two things relate to endothermy?
circulation and respiration
What does circulation mean?
moves heat around
What does respiration do?
lose heat every time you breathe out
Why is endothermy good?
metabolism isn’t dictated by outside temperature
Why is endothermy bad?
requires more calories (why birds and mammals have to eat so much)
What are the two subclasses of mammals?
- Prototheria
- Theria
Which is more primitive, Prototheria or Theria?
Prototheria
What is Prototheria?
lay shelled eggs, one living group
What is the living group of Prototheria?
monotremes
What are Theria?
Viviparous and 2 living groups
What does viviparous mean?
live young
What are the two living groups of Theria?
marsupials and placental mammals
What are the living monotremes?
- duck billed platypus
- short nosed echidna
- long nosed echidna
What feature do monotremes have?
single opening, cloaca, for digestive and reproductive tracts like birds
What are Monotremes?
egg laying mammals
What are marsupials?
pouched mammals
What are parts of eggs of marsupials?
have chorion and amnion but no shell
How are embryo’s nourished in marsupials?
by abundent yolk
What happens for marsupials after birth?
crawls into marsupial pouch and attaches to nippled and continues to develop
What was the largest carnivorous marsupial?
Tasmanian Tiger
What are placental mammals?
produce a true placenta that nourishes embryo throughout its development
What does placental mammals form?
both fetal and maternal tissue
What is the function of the placenta?
prevent most infections from crossing border
What can cross the border of placenta?
nutrition and antibodies
What gave rise to humans?
primates
What did primates evolve that allowed them to succeed in an arboreal environment?
- grasping fingers and toes (first digit is opposable)
- stereoscopic vision
What is stereoscopic vision?
eyes are shifted towards the front of the face
Why is stereoscopic vision good?
better depth perception, for better hunting and seeing threats
is flying a unqiue bird trait?
no
What animals make up the majority of placental species?
rodents and bats
Why are there so many bats?
bats live in caves and trees, so they can evolve separately as population is isolated
