lecture test 5 Flashcards
heterochrony
evolutionary change in the relative time of appearance or rate of development of characteristics from ancestor descendant
paedomorphosis
retention of ancestral juvenile features in later stages of the ontogeny of descendants
function of endostyle
secretes mucus that traps small food particles brought into the pharyngeal slits
what organ is derived from the endostyle
thyroid gland
describe hemichordata
worm like, acorn worm, ciliated, complete digestive system, long and circ muscles, marine, free living
why is a hemichordate not placed in chordate
only contains gill slits and notochord
notochord more like stomochord not homologous to notochord
what defines developmental patterns
sequence of events
length of each stage
heterochrony
change in timing
define chordata
contains all five characteristics
craniate
bony or cartilaginous cranium surrounding brain
gnathastomata
jawed
vertebrae
bony structure
whats the list of ancestral to derived of chordate features
chordata, craniate, agnatha, vertebrae, gnathastomata
endochondral bone is
bone that replaces cartilage
ostracoderms
vertebrates, no jaws, bony sheild like plates, numerous but very small teeth, no paired fins
placoderm
vertebrates, articulated jaws, armored more than ostracoderms, paired appendages, pelvic and pectoral
acanthodians
vertebrates, jawed, loss of bony plates, replaced with dermal structures that resemble shark dermal dentacles
homocercal tail
tail equal on both sides, in bony fish, more derived
heterocercal tail
not even tails, larger on one side, more ancestral, sharks
diphycercal caudal fin
lobe finned fish
placoid scales
heavy larger and thicker, most ancestral
ganoid scales
romboidal, thick center and thinner edges
ctenoid scales
derived, circle with one side of jagged edge
cycloid scale
derived, round with thickness in center, circular structure in middle
label scales from ancestral to derived
placoid, ganoid, ctenoid, cycloid, no scaled
physostomous
tube connecting swim bladder to esophagus
physoclistous
gases diffuse into and out of the blood stream through rete merabile and ovale
why is counter current exchange more efficient in diffusion
maintain opposite flow so a concentration gradient is kept for a greater distance resulting in a more efficient exchange
how do fish hear
using webbarian ossicles that are little bones adjacent to the swim bladder, pick up vibrations from swim bladder and transmit to brain which becomes auditory
hyperosmostic regulation
high solute conc inside fish, water goes into fish and salt comes out, fresh water fish, void excess water in dilute urine, in gills there are special cells that absorb salt
hypo-osomotic regulation
low solute conc in fish, water exits and salt goes in, saltwater fish, gills have salt secretory cells, to replace water loss, animal drinks salt water, additional salts can be placed in intestine and excreted with feces
ecototherm
having a body temp derived from heat aqcuired from environment
endothermi
having a body temp determined by heat derived from animals own oxidative metabolism
defining features of amphibia
sensory organs move to head, respiration used as cutaneous gills and lungs, eyelids and glands, chromatophores, flattened skulls and pelvic girdle, legs are place out to the side of body, three chambered heart,ectothermic
heart features
atria and ventricle, oxygenated and deoxygenated blood, introduce double circulation
anapsid
no openings behind eye orbits
diapsid
2 openings behind eye orbits
synapsid
single opening behind eye orbits
what are the modifications of the skull in birds
fusion of bones, loss of certain bones, hollowing out of bones
what bones did birds lose
phalanges of forearm
what fusion of bones of birds
pygostyle, and synosacrum
what is the keel
elaboration of bone to create a larger area for attachment
what are feathers made of
keratin
down feathers
insulating
countour feathers
flight feathers, larger category
filoplume feathers
degenerate feathers
what are the structures in a feather
barb with barbules that look like hooks, calamus, rachis, vane
do birds have teeth
no, keratinized sheeth over jaw
do birds have a bladder
no
do birds have sweat glands
no
what digestive features do birds have
crop, stomach which is made of proventriculous and gizzard, moves to intestine then coaca
what about respiration in birds
no diaphragm, one lung, multiple distinct air sacs located throughout body located anteriorly and posteriorly
what are some derived features in mammals
heterodont, secondary palate, turbinate bones in nasal cavity, diaphragm, modifications of skull to create bones for hearing
what are the hearing bones
malleus, stapes, and incus
monotremes
oviparous, egg laying
marsupalia
transient placenta, live embryonic young emerge and migrate to pouch like structure, milk glands become source of nutrition, embryo completes development in marsupian
eutheria
viviparous, create true placenta, endothermic, hair, sweat, oil, scent and milk glands
where are horns found
both male and female
what is made up of horns
keratin layer that surrounds underlying bone
growth and do they fall off? horns
grow continously and never fall off
horns branched?
no
where are antlers found
males
what is made up of antlers
new bone is created underneath, vascularized tissue
growth and do they fall off? antlers
seasonal growth, they do fall off and are replaced
antlers branched
yes
significance of secondary palate
separates oral from nasal cavity, and allows breathing and chewing at same time
homodont
teeth all the same
heterodont
differences in teeth
what is the evolutionary line in mammals
synapsids, pelycosaurus, therapsids, cynodonts, mammalia
what are vibrissae
ennervated hairs
another name for coat
pelage
a pelage is made of
under hairs and guard hairs
what are underhairs
insulation
what are guard hairs
protective, coloration
functions of hairs
cryptic coloration, insulating effect, predator difference, temp regulation but also cooling
growth in hair follicle
new cells develop at blood vessel at base of hair, pushes keratinized cells towards end of hair
function of diaphragm muscle
loss of lumbar ribs, helps chest cavity volume increase and decrease
