lab practical 3 Flashcards
what is in the phylum hemichordata
worm like/ acorn worm
what is significant of hemichordatas
exhibit half of the characteristics that define chordates
what are the five characteristics in chordatas
dorsal, hollow nerve cord pharyngeal gill slits metamerism post anal tail endostyle notochord
what are the subphylum of chordata
urochordata, cephalochordata, vertebrata
what are urochordata
sea squirts or tunicates
movement in sea squirts
adults are sessile and are filter feeders
why are urochordata put into chordata group
larval form shows all five characteristics while adulthood only has two of the five
cephalochordata are
lancelets
significance of lancelets
display all five characteristics as an adult
chondrichthyes have what type of internal skeleton
cartilage skeleton
class actinopterygii are
ray finned fish
why are ray finned fish greater in complexity than agnathan fishes
evolution of jaws and paired appendages
in ray finned fish what protects the central nervous system
cranium and vertebral column
what does a swim bladder do
help with buoyancy
amphibians are the first
tetrapods
what allowed amphibians to survive on land
appendicular girdles, appendages for terrestrial locomotion, simple lungs, thing vascularized skin, neck
why are amphibians tied to the water
reproduction
do not produce dry resistant eggs
class reptilia has what that helps stay on land
dry skin covered with scales, regulatory ectotherms, increased metabolism, more flexible limbs, stronger jaw
reproductive process in reptiles
amniotic egg (land eggs), internal fertilization
which class is the first truly endothermic group
class aves
in order for an animal to be endothermic what do they need
high metabolism, which produces heat
how do class aves preserve heat
feathers serve as insulators
what is another word for feathers
plumage
what are other functions of feathers
flight, behavioral functions, and sensory functions
what are the sexual dimorphisms in class aves
different plumages, color, feather shapes
what is special about class aves skeleton
lighter to allow for flight
what are the three types of feathers
remiges, coverts, and down feathers
what are remiges
flight feathers
characteristics of remiges
long, stiff, flight
characteristics of coverts
shorter contour feathers, cover gaps of regimes feathers
characteristics of down feathers
less organized, short and lie under the contour feathers
what is in a contour feather
rachis, vane, calamus, barbs
what is a rachis
long central shaft
what is a vane
flat, attached to side of rachis
what is the calamus
hollow portion at the base of the shaft that anchors the feather
what is a barb
vane composed of lateral branches
what is the more defined order of feathers
primary, secondary, tertiary, covert, semi plume feather and down feather
what features are special for mammals
single lower jaw bone (dentary), mammary glands, hair, 3 middle ear ossicles, and diaphragm muscle
what is vivipary
live birth of young
another word for hair
pelage
function of pelage
insulator to retain body heat
how is hair classified
function and growth pattern
angora is
hair that grows continuously
definitive hair is
hair that only grows to a certain length and then stops growing
describe vibrissae hairs
long stiff hairs that are well innervated at the base
function of vibrissae hair
tactile receptors, whiskers for example
function of guard hairs
protection
what are the three major types of guard hairs
awns, bristles, and spines
describe awns
definitive growth, covers bodies of most mammals
describe bristles
long hairs with angora growth
describe spines
barbed and have definitive growth
function of under hairs
insulators
three types of under hairs
wool, fur and velli
describe wool
angora hair
describe fur
definitive hair
describe velli
very fine fuzz hair around embryo
how is color determined in a mammal
amount of eumelanin and pheomelanin
eumelanin
black and browns
pheomelanin
reds and yellows
cryptic coloration
conceals individuals from predators, blend in with surroundings
disruptive coloration
sharply contrasting patters of light and dark colors, allow animal to blend into patterns of light and dark
countershading
dorsum is dark and ventral is light
true horns
only occur in female bovidae, unbranched and permanent
description of true horn
arise from frontal bone, bony core surrounded by epidermal sheath of horn
sheath keratinized
on both male and female
pronghorns
bony core from frontal bone with epidermal sheath
pronghorns shed?
epidermal sheath sheds annually
antlers
consist entirely of bone, branched and shed annually
antlers provide with type of epidermal sheath
blood and nervous tissue that support growth
two types of horn
true horns and pronghorns
