lecture exam 1

phylogeny, origin of chordates, vertebrate groups, life history, integument, skulls

monophyly

group of organisms that includes a common ancestor and all descendants

paraphyly

group of organisms that includes a common ancestor and only some descendants

polyphyly

group of organisms that share a character, but excludes a common ancestor

synapomorphy

traits shared by 2 or more groups that are inherited from a common ancestor

homology

structures that are inherited through common ancestry, which may or may not look similar

homoplasy

structures that look similar or have similar functions, but evolved independently and are not homologous

analogy

homoplastic structures with similar functions but not similar appearance and are not homologous

protostomes

organisms that have a blastopore that forms a mouth first, spiral cleavage, schizocoelic coelom, ectodermal skeleton

deuterostomes

organisms that have a blastopore that forms an anus first, radial cleavage, enterocoelic coelom, mesodermal skeleton

Acoelomate

organism with no central body cavity

Pseudocoelomate

organism with coelom derived from endoderm and mesoderm

Coelomate

organism with a coelom lined with mesoderm

chordate synapomorphies

notochord, dorsal hollow nerve cord, postanal tail, pharyngeal slits, endostyle/thyroid gland

notochord

elastic rod, scaffolding during embryonic development, derived from mesoderm

endyostyle

glandular groove in simple chordates, located on floor of pharynx, secrets mucus to trap food, used in iodine metabolism

thyroid

produces hormones for metabolism, important for cardiovascular health and development and iodine metabolism

dorsal hollow nerve cord

part of the nervous system, derived from ectoderm

postanal tail

derived from segmented muscles and notochord

pharyngeal slits

sac-like projections between mouth and digestive tract, formed from the pharynx, developed into gills in fishes and jaw/inner ear in humans

dorsoventral inversion

process that occurred in hemichordates that led to chordate body plan

Agnathostoma

jawless vertebrates

Myxiniformes

hagfishes; entirely marine, scaleless elongated body, sensory barbels, no bones, ties itself into a knot for leverage while scavenging and evading

Petromyzontiformes

lampreys; 7 pairs of gill pouches, round mouth with keratinous teeth, saliva contains anti-coagulant, larvae ventilate through gills, adults use tidal ventilation

Conodonts

stem vertebrates that had spine/comb-like structures, calcified-like tissues, notochord, myomeres, and pharynx made with dentine and enamel

Ostracoderms

extinct jawless fish; first animals with true bones, dermal exoskeleton, limited endoskeleton supported by notochord, head shield

Gnathostomes

first fishes with true jaws

Placoderms

extinct armored fish; bony head shield, bony plates instead of teeth, bottom-dwellers, included Dunkleosteus

Acanthodians

extinct spiny sharks

Chondrichthyans

cartilaginous fishes; sub-terminal mouth, teeth with enamel-like coating, includes Elasmobranchi and Holocephali

Osteichthyes

bony fishes; ossified skeletons, true teeth, true enamel on scales, gas bladder, includes Sarcopterygii and Actinopterygii

Elasmobranchi

sharks, skates, rays

Holocephali

chimaeras, included Helicoprion

Sarcopterygii

lobe-finned fishes

Actinopterygii

ray-finned fishes

Lissamphibia

caecilians, salamanders, frogs; moist gas-permeable skin, no scales

Amniota

synapsids and sauropsids; capable of sustained locomotion, exhibit parental care, endothermy, efficient lung ventilation

Synapsida

stem mammals included pelycosaurs, therapsids, and cynodonts; only surviving lineages are monotremata, marsupials, and placental mammals

Sauropsida

reptiles, aves, dinosaurs

Diapsida

Lepidosauromorphs, Archosauromorphs, and extinct marine lineages

Lepidosauromorphs

includes squamata and sphenodon

squamata

snakes, lizards, geckos, skinks

sphenodon

tuataras

Archosauromorphs

turtles, crocodilians, aves, and extinct pterosaurs and dinosaurs

ontogeny

embryonic development, from fertilization to birth/hatching

maturation

birth to sexual maturity

senescence

aging, loss of vigor and reproductive ability

zygote

fertilized diploid cell created from fusion of egg and sperm, stage where cleavage begins

morula

solid ball of cells that forms a blastula

blastula

hollow ball of cells, marks the end of cleavage

gastrulation

gut formation from mesoderm, cell is a hollow cup-shaped gastrula, leads to separate germ layers

gastrocoel/archenteron

primitive gut formed during gastrulation

neurulation

nerve formation, cell is a neurula, neural tube forms from ectoderm

vitellogenin

precursor to yolk, necessary for making fat, travels from liver to blood to ovary and ovum

microlecithal

having a little yolk

mesolecithal

having an intermediate-sized yolk concentrated in one pole

macrolecithal

having a large yolk

isolecithal

even distribution of yolk

telolecithal

yolk is concentrated and very large

ovarian/follicle cells

small fluid-filled sac in ovary where egg grows

corona radiata

large group of nerve fibers that send and receive signals between brain regions

cortical granules

organelles in unfertilized oocytes that secret enzymes after fertilization that alter the zona pellucida

zona pellucida

transparent coating on a mammalian ovum before implantation

holoblastic

the complete division of an egg

meroblastic

the incomplete division of an egg

discoidal

a disk of cells is produced at the animal pole of the zygote, occurs in bird eggs

animal pole

active cytoplasm, contains nucleus

vegetal pole

less active cytoplasm, contains yolk

parturition

act of giving birth via viviparity

oviposition

act of laying eggs via oviparity

parition

includes parturition and oviposition

lecithotrophic

obtaining nourishment solely from yolk

matrotrophic

obtaining nourishment before birth through an umbilical cord, and after birth through mammary glands

integument is important for

protection, preventing water loss, sensory perception, communication, coloration, camouflage

structures in the epidermis

hair, feathers, baleen, claws, nails, horns, antlers, beaks

structures in the dermis

connective tissue, blood vessels, nerves, dermal bones

structures from interaction of epidermis and dermis

true teeth, denticles, fish scales

epidermis originates from _

ectoderm

dermis originates from _

dermatome/somite in mesoderm

muscles originate from _

myotome

plies

alternating layers of dermis tissue that strengthens skin, reduces drag in fishes

mucus in fish skin

used for anti-microbial properties, chemical defense from predators; produced from epidermal unicellular glands

placoid scales

projections through epidermis, found in cartilaginous fishes, reduce drag

ganoid scales

found in Actinopterygii, contains ganoine instead of dentine, developed into elasmoid scales

cosmoid scales

found in Sarcopterygii, has a dentin/cosmine layer

alpha-keratin

“soft” keratin, found in all vertebrates

beta-keratin

“hard” keratin, only found in reptiles

Lissamphibia epidermis

contains epidermal poison glands, multicellular mucous glands, thin stratum corneum for cutaneous respiration

Lepidosauria epidermis

contains alpha and beta keratin in layers, regionalization of keratin, beta-keratin sheds in layers

Archosauria epidermis

contains beta-keratin in blocks with alpha-keratin between, osteoderm underneath

Aves epidermis

contains feathers for thermoregulation, salt glands to remove excess, uropygial glands to moisturize, beta-keratin is located in beak and feet, alpha-keratin is located throughout the body

Mammalia epidermis

hair derived from dermal papilla and epidermis, pelage, sebaceous glands, eccrine glands, apocrine glands, mammary glands

underfur

hair used for warmth

guard hairs

hair used to retain moisture

awn hairs

hair used to protect underfur and insulate

sebaceous glands

glands that produce oils to condition skin

eccrine glands

sweat glands located all over body

apocrine glands

sweat glands located in armpits and groin, produce odorless and opaque secretion, modified into ciliary, mammary, and earwax glands

mammary glands

glands that originated in therapsids to keep eggs moist and provide offspring with fluids and nutrients, secretions have anti-microbial properties

chondrocranium

AKA neurocranium, derived from mesoderm, supports and protects brain and sensory organs

splanchnocranium

AKA “visceral” cranium, associated with filter-feeding structures, supports gills and respiratory muscles, contributed to jaws and hyoid in gnathostomes