Bio K103 Chapter 32: The Deuterostomes

multicellularity, tissues, triploblastic, bilateral symmetry, true coelom (coelomates), gill slits in pharynx

what are the ancestral features of deuterostomes?

pentaradial

what symmetry do adult sea stars have?

formation of many new species from an ancestral species, often occurs rapidly in geological time when a new niche opens up

what is adaptive radiation?

living in trees

what does arboreal mean?

common exit point shared by reproductive, excretory and digestive systems (literal translation is sewer)

what is a cloaca?

dry out from lack of water (dehydration)

what does desiccate mean?

animal whose body heat goes up and down with changes in the external environmental temperature, "cold blooded"

what does ectothermic mean?

animal whose body heat is maintained independent of the external temperature

what does endothermic mean?

animals that nourish the embryo via a placenta

what are eutheria?

undergo a change in body form from one developmental stage to another

what is metamorphosis?

animals that raise their young in a pouch (e.g. kangaroos)

what are metatheria?

animals that lay eggs and embryo is nourished by the yolk

what are oviparous animals?

animals that incubate an egg internally, embryo gets nourishment from the yolk, and have live births

what are ovoviviparous animals?

egg laying mammals (e.g. duckbilled platypus)

what are protheria?

animals where the young develop inside the uterus and nutrients are transferred from mother to embryo

what are viviparous animals?

echinodermata and chordata

what phyla are under deuterostomes?

by an outpocket of gut mesoderm

how do deuterostomes develop?

radial, indeterminate

what kind of cleavage do deuterostomes have?

marine, saltwater

what environment do echinoderms live in?

a water vascular system

what is the derived, defining characteristic of echinodermata?

feeding, gas exchange, hydrostatic skeleton

what are the functions of a water vascular system?

oral and aboral

what are the body surfaces in echinoderms?

asteroidea, crinoidea, echinoidea

what are the classes of echinodermata?

plant an arm, use tube feet to move across substrate

how do echinoderms move?

sea stars

what is an example of an organism in class asteroidea?

sea lilies and feather stars

what are examples organisms in class crinoidea?

sea urchins and sand dollars

what are examples of organisms in class echinoidea?

round, flat, no arms

what are the characteristics of class echinoidea?

notochord, dorsal tubular nerve chord, postanal tail, endostyle (tissue in embryo)

what are the derived characteristics of chordates?

vertebral column

what is the notochord in humans?

urochordata, cephalochordata, vertebrates

what subphylum are within the chordates?

tunicates (sea squirts and relatives)

what organisms are within subphylum urochordata?

their body covering, carbohydrate tunic with openings for siphons

what do tunicates get their name from?

all chordate features, swim

what features do tunicate larvae have?

only gill slits (because of filter feeding or respiration)

what features do tunicate adults have?

suspension feeding

how do tunicates feed?

no

are urochordata vertebrates?

no

are cephalochordates vertebrates?

all four chordate features, no paired fins, jaws, sense organs, heart, head or brain

what is the body plan of subphylum cephalochordata?

filter feeders

what kind of feeders are cephalochordata?

vertebral column (cartilage or bone), pronounced cephalization, brain (in cranium), neural crest cells, hox gene clusters, different systems

what are the distinguishing features of vertebrates?

influence development of many structures including melanocytes, smooth muscle, nerves and craniofacial cartilage

what are neural crest cells?

craniate jawlish fish, technically not a vertebrate

what are hagfish?

marine only

what is the habitat of hagfish?

cranium, teeth (keratin projections), notochord, no true vertebra (only craniate without), no true fins (have a long dorsal fold)

describe the body of a hagfish

flexibility, can tie themselves up

what does a notochord in hagfish allow?

scavengers or predators (not as often), burrow into carcass, absorb nutrients across gills and skin, tongue rasps off pieces of carcass

how do hagfish feed?

Secretes slime that covers gills of attacking fish or prey, sneezes if slime covers their own gills

what is a hagfish's mode of defense?

only craniate isosmotic with salt water

what is significant about the body tonicity of a hagfish?

craniate jawless fish, oldest living vertebrate lineage

what are lampreys?

parasitic, structures at end of body that allow them to latch onto predator

describe the lifestyle of a lamprey

structures that allow them to latch to organism leave abrasions, fluid oozes out of the animal and the lamprey consumes it

how do lampreys eat?

marine, freshwater, and estuaries

what are the habitats of lampreys?

class chondrichthyes (cartilaginous) and class osteichthyes (bony)

what are the two classes of jawed fishes?

mostly marine (some freshwater skates)

what is the habitat of class chondrichthyes?

jawed

which are more active: jawless or jawed fish?

have cranium, cartilage infused with calcium salts, not totally calcified but strengthened

describe the skeleton of class chondrichthyes

replaceable because they are modified scales, epitheleal derivatives

describe the teeth of class chondrichthyes

placoid (tooth-like), nonoverlapping

describe the scales of class chondrichthyes

paired

the fins of class chondrichthyes are ___

on the ventral surface, fish can't see prey when they bite

describe the mouth of class chondrichthyes

lateral

what is the gill opening in sharks?

ventral

what is the gill opening is skates and rays?

well-developed brain, blind ended nostrils (smell structures inside), electroreceptors (detect prey), lateral line organ (detects vibrations in water)

describe the senses of class chondrichthyes

heavy, so they sink when they are not swimming (most), pectoral fins provide lift

describe the body density of class chondrichthyes

sharks, skates, rays, and chimaeras

what organisms are in class chondrichthyes?

yes

does class chondrichthyes have a cloaca?

sexually dimorphic, males have a clasper structure (cartilaginous extension of pelvic fin) that transfers sperm to female cloaca

describe reproduction in class chondrichthyes

oviparous, ovoviviparous, viviparous

what are the three modes of vertebrate reproduction?

skates, birds, reptiles, fish, some sharks (but not good example)

what are examples of organisms that are oviparous?

snakes, fish, many sharks (but not good example)

what are examples of organisms that are ovoviviparous?

most mammals, some sharks (but not good example)

what are examples of organisms that are viviparous?

cartilaginous jawed fish

what is class chondrichthyes?

bony jawed fish

what is class osteichthyes?

freshwater and marine

what is the habitat of class osteichthyes?

has a cranium, calcified

describe the skeleton of class osteichthyes

overlapping and flexible, have dermal bone origin, covered by epithelium

describe the scales of class osteichthyes

paired, supported by cartilage or bone

describe the fins of class osteichthyes

anteriorly directed, fish can see what it's eating

describe the mouth of class osteichthyes

internal, covered by operculum

describe the gills of class osteichthyes

a swim bladder

what allows class osteichthyes to maintain buoyancy?

mostly oviparous, external fertilization (lay eggs and then sperm cells are deposited)

describe reproduction in class osteichthyes

ray-finned and lobe finned

what are the groups of bony fish?

ray-finned bony fish

what group are most fish apart of?

rays of cartilage or bone run length of fin

what characterizes ray-finned bony fish?

fins are paddle like, some use lungs instead of gills, gave rise to land-dwelling tetrapods

what characterizes lobe finned bony fish?

amphibia and reptilia

what are the classes of tetrapods?

having two lives (one in water and one on land)

what does amphibia mean?

mostly complete, some adults show pedomorphosis (ex: salamanders)

describe metamorphosis in amphibia

lungs, gills, or skin (not keratinized)

what are the respiratory organs in amphibians?

3 chambers, 2 atria and one ventricle

describe the hearts in amphibians

urodela, anura, apoda

what are the three orders of amphibians?

amphibians with a visible tail; salamanders, mud puppies, and newts

what are urodela? give examples

amphibians with no tail; frogs and toads

what are anura? give examples

amphibians with no feet; wormlike caecilians (internal fertilization)

what are apoda? give examples

cut link to water, amniote eggs: animal develops in liquid environment, liquid is confined inside shell

what was required for organisms to transition to land?

move to land (because they lay shelled eggs)

what were reptilia the first to do?

watertight scales

how do reptilia overcome a dry environent?

lungs divided into many chambers

describe respiration in reptiles

three chambered heart, separates oxygen-rich and oxygen-poor blood

describe circulation in reptiles