what you need to know

Phylum Cnidaria

radial symmetry
aquatic: 2 body forms
no cerphalization
gastrovascular cavity
simple nervous system
mesoglea ( hydrostatic skeleton)
cnidocytes
\#lophotrochozoa

Nematocysts

Small capsules that contain a toxin which is injected into prey or predators

polyp form

sessile, tubular body with mouth at top surrounded with tentacles (corals and sea anemones) [form of Phylum Cnidaria]

medusa form

floating or free-swimming, umbrella shaped body, mouth on concave side, tentacle extend from rim (jellyfish) [form of Phylum Cnidaria]

Phylum Platyhelminthes

flatworms, flukes, tapeworms
ACOELOMATE
cephalization
ganglia and eyespots
gastrovascular cavity with one opening
excretory system: protonephridia w/ flame cells
\#lophotrochozoa

tapeworms

parasitic platyhelminthes
NO MOUTH OR GASTROVASCULAR CAVITY
proglottids- identical segments
scolex\= sucked

flukes

parasitic platyhelminthes
complex life cycle (\>1 host)
ex: chinese liver fluke

Phylum Syndermata (rotifers)

crown of cilia
trophi-aws
PSUEDOCOELOM
alimentary canal
parthenogenosis
\#lophotrochozoa

alimentary canal

digestive tube that extends from the mouth to the anus

parthenogenosis

unfertilized eggs develop into offspring
females reproduce without males

Ectoprocts and Brachiopods

lophopores- crown of ciliated tentacles around their mouth used for feeding

Phylum Mollusca

soft body animals ft\> carbonate shell
TRUE coelomate
cephalization
digestive system- complete with radula to feed

which group is the has the largest number of extinctions

Mollusca

Mollusca body plan

muscular foot (movement)
visceral mass (internal organs)
mantle (shell)

Phylum Nematoda

roundworms
no segmentation
PSUEDOCOELOM
tough cuticle- exo skeletons
\#ecdysozoans\`

Phylum Arthopoda

segmented
exoskeleton
jointed appendages
body regions
ecdysis
open circulatory system

body plan for arthropods

head, abdomen and thorax

ecdysis

molting

hemolymph

the fluid that is circulated through the body of an animal with an open circulatory system

gas exchange in arthropods

gills, tracheal system with spiracles or book lungs

Chelicerares

feed with chelicae (claw-like appendages)
1 pair pedipalps + 4 pairs of walking legs
body: cephalothorax + abdomen

myriapods

centipedes and millipedes
HELLA legs
chewing mandible for feeding
1 pair of antennae ALL terrestrial

Insects

hexapods
complex organ system
malpighian tubules
DIVERSE and IMPORTANT

Crustaceans

2 pairs of antennae, more than 4 pairs of legs, compound eyes
incl. lobster, shrimp, and crab

Malpighian tubules

tubules that excrete metabolic wastes into the hindgut in arthropods

Phylum Echinodermata

pentaradial symmetry
larvae: bilateral symmetry
ORAL and ABORAL sides
contain endoskeleton
WATER VASCULAR SYSTEM

Chordate Characteristics

notochord
dorsal hollow nerve cord
pharyngeal slits
post-anal tail
ALL present as embryo

dorsal hollow nerve cord

flexible, dorsal rod-shaped structure that runs along the nerve cord
CNS

pharyngeal slits/clefts

vertebrate fish- gill support
tetrapods- parts of jaws, inner ear & tonsil

post-anal tail

mult. muscle segments

Phylum Cephalochordata

lancelets
all key ft as adults
burrows tail in and filter feeds, cilia draws seawater into lancelet's mouth
gas exchange occurs across external body surface

Phylum Urochordata

tunicates (sea squirts)
suspension feed with pharngeal slits (only ft. present as adult)

Jawless vertebrates

cyclostomes:
reduced vertebrate
eel-like bodies & no lateral fins
no jaws

hagfish

marine scavengers (most primitive vertebrates)
cartilage skull, notochord
kerantinous teeth

lampreys

jawless parasite on fish
notochord and cartilaginous skeleton

Vertabrates: Gnathostomes

vertebrates with hinged jaws
derived from skeletal rods (support gill slits)
large forebrain( smell & sight)
genome duplication (HOX genes)
lateral line

Lateral line system

detects slight pressure waves of prey/enemy

Gnathostomes: Chondrichthyes

cartilage skeleton
bone minerals lost \= reduce density
buoyancy raised by liver oils & active swimming
bony teeth
predators

oviparous

eggs "laid" and hatch outside the mother's body; embryo develops w/in protective egg-case, fed by yolk

viviparous

embryo fed directly by maternal tissue; live birth

ovoviviparous

egg retained w/in mother, embryo fed by egg yolk; live birth

Gnathostomes: osteichthyes

skeletons remain mostly ossified (mineralized)
oviparous w/ external fertilization
flat scales & slime protect & reduce drag
operculum
lungs modified into swim- bladder for buoyancy

operculum

gill cover, protects & helps pump water over gills

Tetrapods

four limbs w/ wrists & digits (key ft)
neck
pelvic girdle fused to backbone
lung-breathing as adults
ears fir detecting airborne sounds

Tetrapods: amphibia

thin, moist skin; loses h2o easily
gas exchange w/ air across moist skin & lungs
aquatic larval stages
metamorphosis
reproduction near water

Amniote characteristics

amnion protects embryo w/in watery amniotic sac
extraembryonic membranes (sustain embryo with little water loss)
albumen
porous egg-shell
\#internalfertilization

Synapsids

have single opning in the outer layer of the skull just behind eye socket
mammals

Diapsids: Lepidosaurs

evolved from saurospids
two fenestra in skull
modern lizards, snakes and tuataras

Diapsids: Archosaurs

evolved from saurospids
two fenestra in skull
modern crocodiles and alligators, birds

Amniotes: reptiles

tetrapod
descended from 4 limbed ancestors
scaly skin
breath with lungs
negative-pressure breathing by expanding rib cage ("gulping" air )

ectothermic

use environment to warm body
low metabolic rates generate little heat

endothermic

high metabolic rate warms the body
insulation

Amniotes: Archosaurs: Birds origin

diverged from group of bipedal, feathered dinosaur called theropods

Amniotes: Archosaurs: Birds adaptations fro flight

forelimbs\= wings, contour feathers that provide lift
skeleton is lightweight but strong
stubby feathered tail for flight
no teeth
highly efficient respiration system with air sacs (negative pressure)
efficent 4-chambered heart
urogenital adaptations

Urogenital adaptations in birds

no bladder/ urethra
only one ovary
sex organs function only during breeding season
muscular gizzard grinds up food

mammal unique traits

mammary glands, secret milk
gair/fur
teeth vary in size , shape & number
highly developed brain
efficient respiratory and circulatory systems
digestiv tract adaptations for food types
extensive parental care
kidneys
sweat glands

cecum

hold mutualistic microbes that digest cellulose in herbivores
herbivores \= longer digestive tract

Ruminants

mutualistic microbes that digest cellulose in rumen

Mammals: Monotremes

egg-laying mammals
lay shelled eggs (oviparous)
young lap milk
ONLY echidnas & platypus

Mammals: Marsupials

w/ maternal pouch
embryo starts in uterus w/ placenta
fetus born early \=\> crawls into pouch and latches onto nipple to finish development
viviparous

Mammals: Eutherians

placental mammals
young more developed at birth
viviparous

A Hominin

the group consisting of modern humans, extinct human species and all our immediate ancestors

A Hominin characters

bipedal locomotion
ground dwelling
much larger brain
language x complex tools
shorter digestive tract
reduced jaws

homology

forms related by common ancestry

homologous structures

structures derived from a common ancestor

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Allele

An alternative form of a gene.

morphological species concept

organisms that have significant morphological and anatomical differences are different species

biological species concept

organisms that are reproductively isolated from each other are different species

prezygotic barriers

temporal isolation, habitat isolation, behavioral isolation, mechanical isolation, gametic isolation

postzygotic barriers

hybrid inviability
hybrid sterility
hybrid breakdown

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Who evolves, individuals or populations?

populations

genetic drift

random change in allele frequencies that occurs in small populations

gene flow

alleles move between populations via movement of individuals or gametes

genetic variation

Heritable variations in a population.
PREREQ for natural selection

Microevolution

change in allelic and genotypic frequency in a population over generations

Mechanism of Microevolution

1. natural selection
2. genetic drift
3. gene flow

relative fitness

fitness is relative to other individuals in the population

Hardy-Weinberg equilibrium

condition in which a population's allele frequencies for a given trait do not change from generation to generation

Hardy-Weinberg equation

p^2 + 2pq + q^2 \= 1
p + q \= 1

H-W conditions

1. No mutations
2. Random mating
3. No natural selection
4. Extremely large population size
5. No gene flow

directional selection

shifts characters mean value to 1 direction

diversifying selection

intermediates less fit than extremes

stabilizing selection

intermediates more fit than extremes

intrasexual selection

individuals of one sex compete for mates of the opposite sex

intersexual selection

mate choice, individuals of one sex are choosy in selecting their mates from the other sex

root

indicates that an ancestral lineage gave rise to all organisms on the tree

branch point

indicates where two lineages diverged

basal taxon

evolved early and remains unbranched

Sister taxon/taxa

two lineages stem from the same point

polytomy

a branch with more than two lineages

monophyletic group

includes a single common ancestor and all of its descendants\
clade

paraphyletic

consists of an ancestral species and some, but not all, of its descendants

polyphyletic group

doesn’t include the common ancestor

transformation

naked DNA uptake by bacteria

transduction

genes transferred by virus

conjugation

genes transferred by two bacteria via sex pilus

prokaryote reproduction

asexual/ binary
doesn't provide opportunity for diversity
high rate of cell division; many mutations
mutation change phenotype
selection favors best clones
short generation time

oxygenation of atmo

blue-green algae (cyanobacteria)
increase of O2 allowed teh evolution of otehr life forms