vertebrates

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what is the order of classification of life, including all sub and super categories, from most to least broad?

1. domain
2. kingdom
3. phylum
4. subphylum
5. superclass
6. class
7. order
8. suborder
9. superfamily
10. family
11. genus
12. species
13. subspecies

what are the common characteristics of animals?

* multicellular
* heterotrophs
* no cell walls
* collagen
* mobile

what is bilateral symmetry?

body symmetry in which a central longitudinal plane divides the body into two equal but opposite halves (human)

what is radial symmetry?

body symmetry in which the body is shaped like a pie or barrel and can be divided into mirror-imaged halves by any plane through its central axis (jellyfish)

what is segmentation?

repeated segments dividing an animals body

what is metamerism?

linear series of body segments

what are the advantages of segmentation?

* compartmentalization
* specialization with respect to bodily regions

what is cephalization?

concentration of sensory equipment at the anterior end of the body (near the head)

what are appendages?

external body parts, such as limbs

are chordates bilaterally or radially symmetrical?

bilateral

what is the notochord?

flexible longitudinal rod between digestive tube and nerve cord of chordata embryos (and some adults)

what are the two groups of vertebrates?

urochordates and cephalochordates

what does the dorsal nerve chord develop into?

central nervous system

what are pharyngeal slits?

series of pouches separated by grooves along the side of the pharynx, suspend feeding and gas exchange (gill slits)

true or false: members of the family cephalochordata (lancelets) retain the characteristics of the chordate body into adulthood

true

what characteristic is shared between all members of subphylum vertebrata?

presence of backbone

what do the skeletal and nervous systems of vertebrates allow them to become more efficient in?

* capturing food
* evading predators

what are the derived characters of vertebrates?

* spinal chord
* elaborate skull
* fin rays

what are cyclostomes?

living vertebrates without jaws

what are gnathostomes?

vertebrates with jaws

what were the first mineralized skeletal structures?

conodont dental elements

what do the skeletal support rods in gnathostomes become during development?

jaws

what is the earliest known gnathostome?

placoderms

what is the defining characteristic of class chondrichthyes (sharks, rays, skates)?

skeleton primarily composed of cartilage

what is the defining characteristic of superclass osteichthyes (bony fish)?

ossified endoskeleton with a matrix of calcium phosphate

what organ do most aquatic osteichthyes possess to control their buoancy?

swim bladder

what did gut sacs enable early vertebrates to do?

gulp air to obtain extra oxygen

other than swim bladders, what did gut sacs evolve into?

lungs

what is the defining characteristic of class actinopterygii (ray-finned fishes)?

bone structure shaped as rays in their fins for support

what is the defining characteristic of class sarcopterygii (lobe-finned fishes)?

bone structure reminiscent of tetrapod bone structure, including bones like the radius, humerus, and ulna

what unique features among living fish do coelacanths possess?

* rostral organ - part of the electrosensory system
* hinge in the jaw

what does a dipnoi’s lung do?

absorb oxygen and remove waste

why do dipnoi’s breathe air through their swim bladder while buried in the mud?

reduce their metabolic rate

what adaptations do tetrapods have?

* four limbs with digits
* neck
* fusion of the pelvic girdle to the backbone
* absence gills
* ears

what are the characteristics of class amphibia?

* moist skin for gas exchange
* external fertilization of eggs

which classes are amniotes (use amniotic eggs)?

class reptilia and class mammalia

what is an amniotic egg?

egg with a compartment of fluid that bathes the embryo and acts as a hydraulic shock barrier

what is the allantois?

disposal sac in an amniotic egg for certain metabolic waste produced by an embryo

what is the chorion?

membrane in an amniotic egg that exchanges gases between the embryo and the air

what is the amnion?

fluid-filled cavity in an amniotic egg that protects the embryo from mechanical shock

what is the yolk sac and yolk of an amniotic egg?

yolk sac contains the yolk, which is a stockpile of nutrients

what are the characteristics of class reptilia?

* scales containing keratin serving as armor and preventing water loss
* internal fertilization of eggs
* ectothermic (cold-blooded)

what were the original purposes of feathers?

* insulation
* camouflage
* courtship display

what adaptations do class aves (birds) have that allow them to fly?

* lack of urinary bladder
* females have only one ovary
* small gonads
* toothless
* hollow bones

are birds endothermic or ectothermic?

endothermic

what two materials are hairs mostly composed of?

keratin and melanin

what do mammals produce to feed their offspring that no other classes create?

milk (breastmilk)

what did mammals evolve from?

synapsids (mammal-like reptiles)

what is a monotreme and what traits does it have or lack?

* egg-laying mammal
* found only in australia and new guinea
* produce milk but lack nipples

what is unique about mammals in terms of birth?

give birth to premature offspring, who complete their embryotic development while nursing, held in a marsupium pouch

what is a eutherian or placental species?

species that has a longer gestational period, complete embryotic development within the uterus, joined to the mother by the placenta

what is the placenta and what does it do?

* organ that develops in the uterus during pregnancy
* provides oxygen and nutrients to the baby
* removes waste products from the baby’s blood
* attaches to the wall of the uterus