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					Bacteria
History
of Life
       Warm Pond Theory
Oxidizing atmosphere (modern day, O2) would
not support spontaneous generation of organic
compounds – oxygen attacks chemical bonds
Early atmosphere on earth – reducing (H2O,
CH4, H2, NH3) – gases from volcanic eruptions
(Oparin)
Energy provided by lightning and UV (no ozone
layer)
Miller-Urey Experiments
                 Findings
Reducing environment could produce amino
acids and adenine
No complete pathway discovered however
4 step process
– Synthesis of organic compounds from inorganic
– Joining of monomers to polymers (proteins/nucleic
  acids)
– Origin of self-replicating molecules (RNA)
– Packaging of molecules into protobionts (Liposomes)
   Protein or Nucleic acids?
Chicken/egg debate
Nucleic acids need proteins
Proteins need nucleotide sequence for
synthesis
Ribozymes – catalytic RNA, can
synthesize RNA strands
Ribosomal RNA in ribosomes catalyze
protein synthesis
Non-oxygenic photosynthesis
Bacteriochlorophylls
H2S provide electrons
Only 1 photosystem
(PSI)
Cyclic
photophosphorylation
Cyanobacteria – blue-green algae
III. Kingdom Archaea “bacteria”
1. Have no peptidoglycan in their cell wall
2. more closely related to eukaryotes
   (ribosomes)
3. Different lipid composition in plasma
   membranes
4. Live in harsh climates
  a) Methanogens – oxygen-free environment like
     intestines, swamps, sewers (produce methane gas)
  b) Thermophiles – hot environments – undersea
     volcanic vents, hot springs
  c) Halophiles – salty environments – Great Salt Lake,
     Dead Sea
             Eubacteria
 Prokaryotic
(no nucleus) –
larger than viruses
Peptidoglycan in
cell wall
Can be
decomposers
            Classified by
Shape
How they colonize (clusters, pairs, etc)
Cell wall composition
Nutrition
Production of endospores
                   Bacillus - rods




Coccus - round

                 Sprillium - spirals
Gram Stain
               E. Nutrition
1. Photoautotrophic – photosynthetic, use
   sunlight for energy, CO2 for carbon
2. Chemoautotrophic – use inorganic
   compounds as electron donor (energy)
3. Photoheterotrophic – sunlight generates ATP,
   must get carbon from organic molecules
4. Chemoheterotroph – energy and carbon must
   come from organic compounds
Endospore
                       Respiration



              Obligate Anaerobe

Obligate Aerobe                                 Microaerophile
                                  Facultative
                                  Anaerobe
                                                                 Aerotolerant
   Major groups of bacteria
Cyanobacteria - photosynthetic
Chemosynthetic bacteria – nitrifying
Nitrogen-fixing bacteria – live in nodules
on plant roots
Spirochetes – coiled, move in corkscrew
motion, internal flagella
Protists
  Increased biochemical analysis
   could suggest many common
ancestors that swapped DNA freely
How genes
   can be
transferred
Simple cristae and thylakoids
Endosymbiotic Theory
              Evidence
Similarities between prokaryotes and
mitochondria and chloroplasts
– Size
– Similar enzymes in organelles as on plasma
  membranes of bacteria
– Replication
– Circular DNA w/ associated enzymes for
  protein synthesis
– Ribosome structure
        Protein synthesis
Chloroplasts and mitochondria are not
self-sufficient however
Some proteins in organelles come from
nucleus
Other proteins use polypeptides from
organelles and nucleus (ATP synthase)
Could be explained by transformation –
endosymbiont transferred DNA to nucleus
of host cell
Double membranes and diversity of
           plastids
                 I. Protists
A. Characteristics
  A. All are eukaryotic
  B. Most are unicellular
  C. Asexual or sexual reproduction
  D. Classified by how they obtain nutrients
                 PROTISTS

PROTOZOANS         ALGAE        Slime/Water Molds
 (Animal-like)   (Plant-like)      (Fungus-like)
           II. Protozoans
Animal like -
Heterotrophs
Classified by means
of movement
             A. Sarcodina
Rhizopods (amoebas)
Move by
pseudopods –
projections of their
cytoplasm (false feet)
– caused by
extension of
microtubules
Most harmless, but
some cause
dysentery (diarrhea –
3rd leading cause of
death of infectious
diseases)
Sarcodines
Naegleri fowleri –
  brain eating
    amoeba
Foraminifers and Radiolarians
–   Hard shells of
    calcium carbonate
    (skeletons make up
    White Cliffs of
    Dover)
–   Cytoplasmic
    projections extend
    through holes in a
    mineral shell
–   Can be used to date
    other fossils and
    rocks, predict past
    climates and ocean
    currents, and find oil
    deposits
          B. Zoomastigina
Move by flagella (whip-like structures)
Lack mitochondria (fermentation)
Ex. 1. Trichonympha – live in gut of
   termites
   2. Trichomonas – venereal disease
   (parabasalids)
   3. Giardia – freshwater, causes
   dysentery (diplomonads)
   4. Trypanosoma – carried by tsetse fly,
   causes African sleeping
   sickness (kinetoplastids)
Zooflagellates
  C. Ciliophora (alveolata)
Move by Cilia – hair-like projections
Ex.
1. Paramecium
  a) Contractile vacuole – collects & removes
     excess water – HOMEOSTASIS
  b) 2 nuclei – large (macro) nuclei has genes for
     day-to-day living, micronucleus - reproduction
  c) Trichocysts - defense
CILIATES
            D. Sporozoa
Do not move on their own (sessile)
Parasitic
Ex.
1. Plasmodium – in saliva glands of mosquito,
   causes Malaria (4th deadliest infectious
   disease)
  – Drug resistance example
  – Hides in liver and blood cells away from immune
    system
  – Surface proteins constantly mutate
MALARIA
     III. ALGAE – plant like
Autotrophs
Classified by:
1. Color
2. Photosynthetic pigments
3. Whether they are unicellular or multicellular
A. Unicellular Algae
1. Bacillariophyta (stramenopila)
  Golden algae
  Cell walls of silicon
  Ex. Diatoms
 1. Used in cleaners, toothpaste, filters
 2. Makes up plankton
       Direct and indirect food source for ocean animals
       Produce large amount of oxygen (50-70%)
       Source of offshore oil deposits
Diatoms
 2. Pyrrophyta - Dinoflagellata
          (alveolata)
Plankton
2 flagella
Bioluminescent
Ex. Gonyaulax – causes red tide –
type of bloom
1. Depletes water of nutrients
2. Decomposition of dead cells removes
   oxygen from water
3. Fish and other organisms die
Pfiesteria piscicida – can survive in
      sulfuric acid for 30 min
Bioluminescence
RED TIDE
        3. Euglenophyta
Fresh water
Classified as plant – autotroph (has
chloroplasts)
Classified as animal – has eyespot and
flagella to capture food
Ex. Euglena
– Used in sewage treatment plants
– Can cause blooms in pond water
Euglena
       B. Multicellular Algae
Classified by color
          1. Chlorophyta
Green algae, evolved into 1st land plants
Pigment – chlorophyll a & b
Ex
– Single celled – Chlamydomonas
– Colonial – Volvox
– Multicellular - Spirogyra
          2. Rhodophyta
Red Algae
Pigment – chlorophyll & Phycobillin (red)
Used to make nori (sushi wrap) and used
to thicken soup, pudding, frosting
Thickener is caarageenan
         3. Phaeophyta
Brown algae
Pigment – chlorophyll and fucoxanthin
(brown)
Ex. Kelp – largest brown seaweed, used
to thicken ice cream
Sargassum – makes up the Sargasso
Sea
  IV. Slime and Water Molds
Fungus like protists
         1. Myxomycota
Acellular slime molds
Decomposes matter in soil
Forms a plasmodium (like an amoeba) but
has many nuclei
Forms fruiting bodies when food is gone
        2. Acrasiomycota
Cellular slime molds
Single celled
Join together to form fruiting bodies
           Oomycota
Water molds
Form motile spores
Caused Great Potato Famine
               Plant Diversity
              (its not an old wooden ship)

                  Chapter 29-30

Objectives:
1. Understand the 4 main phyla of plants
2. Understand the evolutionary history of plants
3. Look at key adaptations in different groups of plants
1. Four phyla of the plant kingdom
a) Bryophytes (mosses) – 18,000 extant
   species, non-vascular plants
b) Pteridophytes (ferns) – 13,000 species,
   seedless, vascular plants
c) Gymnosperms (cone-bearing) – 721
   species, vascular plants with seeds
   contained in cones (naked seed)
d) Angiosperms (flowering plants) –
   250,000 species – vascular plants with
   seeds contained in flowers/fruit
Intertidal Zones
    2. Charyophyceans and Land
              plants
Similiarities
1. Rose-shaped proteins
    that make cellulose
2. Peroxisome enzymes
    (photorespiration)
3. Sperm structure
4. Formation of cell plate
5. Homologous
    chloroplasts (DNA)
  3. Terrestrial Adaptations
Apical meristems (roots/shoots) – better
exposure to resources
Multicellular, dependent embryos – better
protection
Alternation of generations – produces more
spores (delayed meiosis?)
Walled spores – sporopollenin – most durable
organic material known
Multicellular gametangia – produce many
gametes
Cuticle, stomata, vascular tissue
Sporopollenin
Alternation of Generations
            Bryophytes
Liverworts, hornworts, mosses
Protonema – 1 cell thick
Non-vascular
Anchored by rhizoids (no water uptake)
Prefer moist environments
Gametophyte generation - dominant
Moss Sporophytes
          Moss animation
http://www.sumanasinc.com/webcontent/ani
  mations/content/moss.html
Moss Life
 Cycle
        Pteridophytes (ferns)
• Ferns are the most            Pinnae
  abundant group of
  seedless vascular plants
• 75% of species occur in
  tropics
  Sporophyte generation is
  dominant (gametophyte
  usually hard to find)
  Frond – leaf
  Rhizome – underground
  stem
  Sori (sorus) – clusters of
  sporangia (produce
  spores)
Fiddleheads
Fern Life cycle
Sori
                   Young sporophyte




Gametophyte (prothallus)
        Objectives (Day 2)
Understand the evolutionary significance
of seeds, pollen, and vascular tissue
Understand the pollination and fertilization
of seed plant
                      Seed Plants
9.       Reduced
         gametophyte – able
         to be protected
         inside parental
         sporophyte for
         nutrition and
         protection (UV light)
     -     Spores are now
           contained inside
           sporophyte
               10. Seeds
Plants can live in
more diverse terrain
Protects embryo from
harsh environments
Allows for better seed
dispersal
               11. Pollen
Tough outer coat of
sporopollenin
Male gametophyte
Able to travel large
distances (reach
other plants), created
more genetic diversity
(gene flow)
Specific for each
species of plant
       12. Gymnosperms
30.8
30.4
Gymnosperm Life Cycle
        13. Angiosperms
30.11
Monocots/Dicots
               14. Flowers
Pollination is less
random
Protects embryo
Types of fruit
        16. Seed Dispersal
Fruit has propellers –
dispersed by wind
Burrs, hooks – animal
fur
Tasty fruit – digestive
tract of animals
      Exceptions to the rule
Complete flowers
Incomplete
Bisexual (perfect,
monoecious)
Unisexual (imperfect,
dioecious)
          Flower Diversity
Coevolution –
pollinators
     Pollination/Fertilization
Pollination – pollen
travels from anther to
stigma
Fertilization – pollen
travels from stigma,
through style, and
fuses with egg inside
ovary
Plants can prevent
self-fertilization
(preserve genetic
variation)
Gametophyte development
Kingdom Animalia
New Data/Phylogenetic tree
Simple to Complex
              Animals
Multicellular, heterotrophs
Lack cell walls, structure from proteins
Nervous, muscle tissue – Response to
environment
Hox genes (development/differentiation)
Choanoflagellates – multicellular
           protists
Symmetry/Cephalization
Germ Layers
Coelom – fluid-
  filled body
 cavity lined
 entirely with
  mesoderm
 Coelomates

Archenteron –
 developing
digestive tract

 Blastopore –
opening of the
 archenteron
Phylum Porifera
Cnidaria
Platyhelminthes
Rotifera
Mollusca
Annelida
Nematoda
Arthropoda
Echinodermata
Chordata

				
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