Alpha-proteobacteria
• Agrobacterium
• Ti plasmid used for plant genetic
engineering
• Rhizobium
• forms symbiotic root nodules w/legumes
(Fabaceae)
Gamma-proteobacteria
• Escherichia
• E. coli model organism
• catalase-positive
• Salmonella
• catalase-positive
• typhoid, food poisoning
• most subspecies produce hydrogen sulfide
as a metabolic byproduct
Gram-positives
• Bacillus
•
•
•
•
endospore-forming
catalase-positive
anthrax
B. subtilis model organism
• Streptomyces
• originated many antibiotics
(streptomycin, tetracycline,
chloramphenicol)
• high-GC genomes
Others
• Anabaena
• cyanobacterium
• heterocysts engage in nitrogen fixation
• symbiotic relationship with Azolla fern
(functionally similar to
Rhizobium+legumes)
• Thermus
• T. aquaticus DNA polymerase used in PCR
Archaea
• Similar to Eukarya:
• histone-associated DNA
• translation initiated with methionine
• Similar to Bacteria:
•
•
•
•
external morphology
circular genome
operons, polycistronic mRNA
no introns/RNA processing
Examples
• Methanobacterium
• type of methanogens (methanogens are
not monophyletic)
• obligately anaerobic
• reduce CO2 to CH4 using H2
• Thermoplasma
• high-temperature acidophiles
• facultative anaerobes (can respire using
sulfur in anaerobic conditions)
• no cell walls
• Halobacterium
• aerobic
• high-salt environments (protein function)
• uses bacteriorhodopsin as proton pump
for ATP generation
• Sulfolobus
• high-temperature acidophiles
• can grow lithoautotrophically by oxidizing
sulfur to sulfates
• chemoheterotrophs by using sulfur to
oxidize carbon compounds
Euglenozoa – Euglenids
• possess chloroplasts through
secondary endosymbiosis of green
algae (thus their chloroplasts have
three membranes)
• no cell wall, but pellicle made of
protein
• pyrenoids store paramylon
(carbohydrate similar to starch)
• Euglena
Euglenozoa – Kinetoplastids
• all possess a kinetoplast: dense DNA
granule within mitochondrion, located
at the cell’s basal body
• Trypanosoma
• obligate, heteroxenous parasites
• T. cruzi – Chagas’ disease
• T. brucei – African sleeping sickness
Stramenopiles – Phaeophyta
• brown algae
• all multicellular
• possess xanthophyll called
fucoxanthin, giving distinctive color
• body called a thallus
• holdfast “root”
• stipe “stem”
• pneumatocysts provide buoyancy
• Sargassum
• oogamous, diploid body
Stramenopiles – Bacillariophyta
• diatoms
• enclosed in silicon-based cell wall
called a frustule
• sexual reproduction involves
formation of an auxospore
• four-membraned chloroplasts
(characteristic of all stramenopiles)
• Diatoma
Alveolates – Apicomplexa
• intracellular animal parasites w/
complex life cycles
• apicoplast: four-membraned plastid
involved in host cell penetration
• generally sporozoites infect a host,
replicating in cells to produce
merozoites which infect other cells
• Plasmodium
Alveolates – Ciliates
• possess a diploid micronucleus (for
reproduction) and polyploid
macronucleus (for transcription)
• asexual reproduction occurs via binary
fission
• conjugation: micronuclei undergo
meiosis and haploid micronuclei are
exchanged over the mating bridge
• organelles called trichocysts that
release hairs in response to stimuli
Alveolates - Dinoflagellates
• characterized by 2 flagella, one
transverse and one longitudinal
• lack histones, nucleosomes
• haploid
• most possess a dinokaryon nucleus
• DNA condensed throughout interphase
• nuclear membrane does not break down
• mitotic spindle is extranuclear
• Ceratium
Rhodophyta
• red algae
• color due to phycoerythrin pigment
• carbohydrate stored as floridean
starch, more highly branched than
amylopectin
• many exhibit complex alternation of
generations with 2 sporophyte
generations
• Chondrus
Amoebozoa - Lobosea
• Unikonts (previous protists were
dikonts)
• Amoeba
• endoplasm/ectoplasm: differential flow
of cytoplasm causes movement
• actin-based pseudopodia appendages
Amoebozoa – Eumycetozoa
• Slime molds
• Myxogastria:
• plasmodial slime molds
• single-celled, haploid
myxamoebas/myxoflagellates
• extended diploid multinucleate
reproductive form called plasmodium
• Dictyostelia:
• cellular slime molds
• single-celled and mononucleate haploids
• aggregate into multiorganismic
“pseudoplasmodium” (still haploid)
• sexual reproduction involves macrocyst
formation
• Dictyostelium
Zygomycota
• characterized by zygosporangium, a
resistant diploid reproductive
structure
• cell walls made of chitosan,
deacetylated chitin
• Mucor
Ascomycota
• sexual reproduction involves formation of
asci in an ascocarp
•
•
•
•
each ascus has eight ascospores
tissue layer containing asci: hymenium
apothecium: hymenium open outward
cleistothecium: hymenium closed, bursts
open
• perithecium: hymenium closed off except
for a single pore
• most lichens have ascomycete
mycobionts
• Penicillum
• Saccharomyces
• no ascocarps, naked asci
• Claviceps causes ergot infections
Basidiomycota
• Long heterokaryotic stage
• Clamp connections to coordinate
division of dikaryotic nuclei
• Form basidia containing
basidiospores, which germinate into
haploid mycelia
• Agaricus
• Rusts:
• obligate parasites, many requiring more
than one host
• complex life cycle w/ up to 5 different
spore types
• Puccinia
Animals
• Porifera
• eukaryotic, multicellular
• heterotrophic
• no cell walls
Porifera
• water flows through ostia out to
osculum
• flagellated choanocytes collect food
• asconoid, synocoid, leuconoid
structures
• Spongia
Animals
• Porifera
• Cnidaria
• Anthozoa
• Scyphozoa
• Hydrozoa
• Ctenophora
• true tissues
• germ layers
Cnidaria
Polyp?
Medusa?
Species
Anthozoa
Yes
No
Anemonia,
Corallium
Scyphozoa
Yes
Yes
Aurelia
Hydrozoa
Yes
Yes
Hydra
Ctenophora
• Two-cell layer surrounding mesoglea
(one-cell thick in Cnidaria)
• swim using combs of cilia
• no cnidocytes; instead colloblasts
release adhesive substance
• Mertensia
Animals
• Porifera
• Cnidaria
• Ctenophora
• Bilateria
• Protostomia
• Platyhelminthes
• Lophotrochozoa
• Ecdysozoa
• triploblastic body
• bilateral symmetry
• schizocoelous development
• spiral, determinate cleavage
Platyhelminthes
• Turbellaria:
• paraphyletic, all free-living flatworms
• Pseudoceros
• Cestoda:
• strictly sexual reproduction
• Echinococcus
• Trematoda:
• heteroxenous parasites (mollusk +
vertebrate)
• Schistosoma
Animals
• Porifera
• Cnidaria
• Ctenophora
• Bilateria
• Protostomia
• Platyhelminthes
• Lophotrochozoa
• Mollusca
• Annelida
• Ecdysozoa
• Trochophores: produce
trochophore larvae (with two
bands of cilia around middle)
• Lophophore: band of tentacles
around mouth
• closed digestive systems
• coeloms
Lophotrochozoa – Mollusca
• Gastropoda:
• Arion (slugs)
• Achatina (snails)
• Cephalopoda:
• Nautilus
• Sepia (cuttlefish)
• Bivalvia:
• Pinctada (pearl oysters)
Lophotrochozoa – Annelida
• Polychaeta:
• parapodia serve as gas exchange
• protostomium equipped with palps,
nuchal organs, eyes, antennae
• Nereis
• Oligochaeta:
•
•
•
•
no parapodia
prostomium not well-developed
Lumbricus
Hirudo (leech)
Animals
• Porifera
• Cnidaria
• Ctenophora
• Bilateria
• Protostomia
• Platyhelminthes
• Lophotrochozoa
• Mollusca
• Annelida
• Ecdysozoa
• Nematoda
• Arthropoda
• periodically shedding cuticle
Ecdysozoa – Nematoda
• pseudocoelomates
• Caenorhabditis
Animals
• Porifera
• Cnidaria
• Ctenophora
• Bilateria
• Protostomia
• Deuterostomia
• Echinodermata
• Asteroidea
• Holothuroidea
• Echinonoidea
• Chordata
• triploblastic body
• bilateral symmetry
• enterocoelous development
• radial, indeterminate cleavage
Echinodermata
• Asteroidea:
• Linckia
• Echinoidea:
• Diaderna
• Holothuroidea:
• Holothuria
Animals
• Porifera
• Cnidaria
• Ctenophora
• Bilateria
• Protostomia
• Deuterostomia
• Echinodermata
• Chordata
• Urochordata
• Cephalochordata
• Vertebrata
• notochord
• dorsal nerve cord
• pharyngeal slits
• post-anal tail
Urochordata (Tunicata)
• some are sessile; others are freefloating
• filter feeders, with incurrent +
excurrent siphon
• Ascidia
Cephalochordata
• lancelets
• notochord persisting throughout life
• filter-feeders, usually half buried in
sediment
• Branchiostoma
Animals
• Porifera
• Cnidaria
• Ctenophora
• Bilateria
• Deuterostomia
• Chordata
• Vertebrata
• Hyperoartia
• Gnathostomata
• cephalization
• vertebral column
• doubling of Hox clusters
(lancelets, tunicates have only
one set)
• neural crest
Hyperoartia
• parasitic or filter-feeders
• Petromyzon
Animals
• Deuterostomia
• Chordata
• Vertebrata
• Gnathostomata
• Chondrichthyes
• Osteichthyes
• jaws (developed from first gill
arch)
• another doubling of Hox clusters
(now there are four)
• lateral lines
Chondrichthyes
• contain Leydig’s organ, involved in
erythropoiesis
• skin is covered in denticles
• Carcharodon (great white)
• Dasyatis (stingrays)
• Apristurus (catshark)
Animals
• Deuterostomia
• Chordata
• Vertebrata
• Gnathostomata
• Osteichthyes
• Actinopterygii
• Sarcopterygii
• lungs (swim bladders)
• one dorsal fin
Actinopterygii
• fin rays (fins supported by bony
spines)
• Carabus (sturgeons)
• Barbus (barbell)
• Anguilla (freshwater eels)
• Salmo (salmon)
Animals
• Vertebrata
• Gnathostomata
• Osteichthyes
• Sarcopterygii
• Dipnoi
• Coelocanthomorpha
• Tetrapoda
• bony fins surrounded by muscle
• two dorsal fins
• teeth with true enamel
Coelocanthomorpha, Dipnoi
• Coelocanthomorpha:
• Latimeria
• Dipnoi:
• true lungs (homologous to land
animal lungs)
• almost all obligate air breathers
• Protopterus
Animals
• Vertebrata
• Gnathostomata
• Osteichthyes
• Sarcopterygii
• Tetrapoda
• Amphibia
• Amniota
• four limbs evolved from fins
• head separated from neck by
vertebrae
Amphibia
• Caudata (salamanders):
• possess tail
• aposematism
• Salamandra
• Anura (frogs)
• no tail
• Rana (pond frogs, bullfrogs)
Animals
• Vertebrata
• Gnathostomata
• Osteichthyes
• Sarcopterygii
• Tetrapoda
• Amniota
• Reptilia
• Mammalia
• terrestrially adapted egg w/ four
membranes
• larval stage
“Reptilia”
• Testudines (Chelonia, tortoises)
• Testudo
• Squamata (lizards, snakes)
• movable quadrate bone
• Gekko, Python
• Crocodyliomorpha
• Crocodylus
• Aves…
Aves
• Paleognathae:
• most basal birds
• mainly flightless
• Struthio (ostrich)
• Galloanserae:
• fowl/waterfowl
• Gallus (chicken)
• Neoaves:
•
•
•
•
•
all other birds (more derived)
Columba (dove)
Passer (sparrow)
Apus (swift)
Dendrocopos (woodpeckers)
Animals
• Vertebrata
• Gnathostomata
• Osteichthyes
• Sarcopterygii
• Tetrapoda
• Amniota
• Mammalia
• mammary glands for feeding
young
• middle ear bones (incus,
malleus, stapes)
• hair
• neocortex
Mammalia
• Monotremata:
• lays eggs
• no corpus callosum
• have cloaca (monotreme = “single
opening”)
• extant species lack teeth
• Ornithorhynchus (platypus)
• = “bird snout”
• Marsupialia:
• premature viviparous birth; young are
carried in pouches
• Macropus (kangaroos)
• “large foot”
• Eutheria
• most contain corpus callosum
Mammalia – Eutheria
• Xenarthra (sloths, armadillos, anteaters)
• lowest metabolic rate of eutherians
• xenarthrism: vertebrae have extra
articulations
• ischium fused to sacrum
• Bradypus (sloth)
• “slow foot”
• Lagomorpha (rabbits)
• four upper incisors (rodents have two)
• herbivorous (rodents are omnivorous)
• Lepus (hares, jackrabbits)
• Rodentia
• includes 40% of mammal species
• constantly growing incisors
• Rattus (rats)
Eutheria contd.
• Primates:
•
•
•
•
large brains
forward-facing, stereoscopic binocular eyes
Cercopithecus (old World monkeys)
Pan (chimpanzees)
• Chiroptera:
• “hand wings” – bats
• Pteropus (flying foxes – largest bats)
• Phyllostomus (leaf-nosed bat)
• Eulipotyphla:
• hedgehogs, moles, shrews
• incorporates most of what was formerly
Insectivora
• Sorex (shrews)
Eutheria contd.
• Carnivora:
• highly specialized zygomatic arch
• includes bears, dogs, cats, pinnipeds (sea otters,
sea lions)
• Panthera (large cats – tigers, lions, panthers)
• Canis (wolves, foxes)
• Cetartiodactyla:
• Cetacea (whales, dolphins) + Artiodactyla (eventoed ungulates – pigs, hippos, deer, sheep, goats,
etc.)
• Sus (pigs)
• Cervus (deer)
• Giraffa
• Camelus
• Bison
• Orcinus (orcas)
• Balaenoptera (blue whales)
Eutheria contd.
• Perissodactyla (odd-toed ungulates)
• walk mainly on third toe (artiodactyls
spread weight evenly between 3rd and 4th
toes)
• non-ruminants
• Tapirus (tapirs)
• Equus (horses)
• Rhinoceros
• Proboscidae:
• elephants and hyraxes
• Elephas