Lab 10: Chordata Flashcards
Why are adult tunicate’s called “sea squirts”?
they squirt water out of their excurrent siphon when disturbed
What phylum are chordata most closely related to?
Echinodermata
What kind of symmetry do chordates have?
bilateral
Do chordates have a coelom?
yes
What are the four characteristics that all chordates share at some point in their life?
-Notochord
-Dorsal, hallow nerve cord
-Pharyngeal slits
-Postanal tail
What are the two subphylum of invertebrate chordates?
-Urochordata
-Cephalochordata
A transitional fossil is:
a fossil that has some ancestral characteristics and some newly derived characteristics.
Which of the following is a tetrapod but not an amniote? Choices: Frog, snake, bird, badger
frog
The pattern in the limbs of tetrapods described by Neil Shubin in the video (one bone, two bones, lots of little bones, digits) is evidence that:
the limbs of a bird, lizard, frog, human are homologous.
Which of the following is chordates closest relative? Choices: sea star, squid, horseshoe crab
Sea star
Which of the following is an invertebrate chordate? Choices: tunicate(sea squirt), hagfish, lamprey, shark
tunicate (sea squirt)
An agnathan is:
a chordate without jaws
What does this description match:
The chordate hallmark that is a a flexible rod supporting the bodies of chordate embryos and is retained or modified in some adult chordates.
notochord
Mammal clade that gives birth to young that are nourished for a very short time by the placenta and then finish development in a pouch.
Marsupial
Which mammal clade lays eggs?
Monotreme
Which mammal clade gives birth fo fully developed young that were nourished through development by the placenta.
Eutherian
What kind of heart does a frog have?
Three chambered
What kind of heart does a horse have?
Four chambered
What kind of heart does a chicken have?
Four chambered
What kind of heart does a crocodile have?
Four chambered
What kind of heart does a snake have?
Three chambered
What kind of heart does a fish have?
Two chambered
Which type of animal devotes a greater proportion of its energy to maintaining body temperature?
Endotherm
List three endotherms
-Bird
-Horse
-Koala
(all birds and mammals are endotherms)
Which subphylum of Chordata retains all four key chordate characteristics as adults?
Cephalochordata
animals in subphylum Urochordata are commonly called what?
Tunicates
Where does the word “tunicate” come from?
comes from a tunicates outer covering, called the
tunic, that protects the animal from predator
Describe the notochord in a chordate
flexible rod that supports body of chordate embryos
Describe the dorsal, hallow nerve chord
eventually will become the spinal chord
Describe the pharyngeal slits
openings that connect to the pharynx, or throat to the outside of the neck and help function in filter feeding
Describe the post anal tail
skeletal extension of the posterior end of the body beyond the anus
What are tetrapods?
Animals with four limbs
What is an endotherm?
-Birds and mammals
-Heat from within, narrow range even when environment changes
What is an exotherm?
-Fish, amphibians, snakes, lizards
-Mirrors temp of surroundings
What is an amniote?
a group of vertebrates that includes reptiles, birds, and mammals
What are gnathostomes?
Organisms with jaws
As sessile adults, what key chordate features do urochordata’s lose?
The notochord and tail, their dorsal hollow nerve chord becomes reduced but pharyngeal slits are retained
What are dermal denticles?
They are tiny v-shaped scales that decrease drag and turbulence which allow the shark to swim faster and more quietly.
What is the main reason fins are so adaptive for sharks?
They move the shark forward, stabilize, and prevent rolling as they swim through the water. It provides a “lift” as it swims
How do skates do gas exchange?
Through their gills located on the ventral surface, they bring water in for gas exchange across the gills primarily through their spiracles rather than their mouth
What does the swim bladder do?
It provides neutral buoyancy which is the ability of an organism to use little or no energy to stay at particular levels of water
Do both ray-finned fish and lobe-finned fish both have a swim bladder?
No, only ray-finned fish. The lungs were retained in lobe-finned fish.
What is an anatomical placode?
epidermal thickening where skin appendages (scales, feathers, hair) develop
T/F: Snakes and lizards are fully terrestrial
True
T/F: Amphibians are fully terrestrial
False, they lack an amniotic egg
What kind of heart do birds, crocodilians, and mammals have?
4-chambered heart, 2 atria and 2 ventricles
Explain the circulation in a 4 chambered heart
Deoxygenated blood is received by right atrium and then pumped to the lungs by the right ventricle. Oxygenated blood is received by the left atrium and then pumped to the body by the left ventricle
