Download Diversity Survey 1

A Bit of Taxonomy…
Today:
• Comments on Sexual
Encounters?
• Onto Prokaryotes
• Ubiquity Survey
• Meeting the Protists
• The Fungi and
Beyond?
Studying Diversity: Taxonomy
Looking at
the
Prokaryotes
Domain (Eukarya)
Kingdom (Animalia)
Phylum (Chordata)
Class (Mammalia)
Order (Primata)
Genus (Homo)
Species (sapiens)
Where Did the First Life Come From?
Where Did the First Life Come From?
Step 1: Abiotic Synthesis
of Organic Monomers
Spontaneous
Generation??
Hey look! I’ve got
amino acids,
sugars, lipids and
nucleotides in
here!
Biogenesis?
Photo: NIH
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Where Did the First Life Come From?
Step 2: Abiotic Synthesis
of Polymers (like
proteins and nucleic
acids)
Where Did the First Life Come From?
Step 3: Origin of Self-Replication Molecules
Binding to clay particles may
have helped facilitate this in
the absence of enzymes!
Where Did the First Life Come From?
Step 4: Formation of Pre-Cells (Protobionts)
Prokaryotes Today: Major
Characteristics
What Did the First Life Look Like?
Prokaryotes show up
in the fossil record
~3.5 billion years
ago!
Prokaryotes Today: Major
Characteristics
They’re ubiquitous!
How do we
know that if
they’re so
small?!?
Bacteria in a dental plague
Bacteria on the surface of a
contact lens.
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Prokaryotes Today: Major
Characteristics
Two Major Groups:
1.
2.
Prokaryotes Today: Major
Characteristics
Three Major
Shapes/Morphologies:
Bacteria
1.
2.
Archaea
(“Extremophiles”)
3.
Prokaryotes Today: Major
Characteristics
Nutritionally Diverse! May be:
1.
Photoautotrophic
2.
Chemoautotrophic
All of these terms
3.
Photoheterotrophic
describe how you get
4.
Chemoheterotrophic your energy (chemical
or light source) and
where you get your
carbon compounds
(make them yourself, or
eat others!)
Prokaryotes Today: Major
Characteristics
Important as Disease
Causing Agents!
Many cause disease
through the
production of
endotoxins or
exotoxins
Prokaryotes Today: Major
Characteristics
Important as Nutrient Cyclers!
Cocci
Bacilli
Spirochetes
You Try! Questions 1 & 2
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Some pointers…
What question will you
ask?
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Next Up: Evolution of the Protistans!
What the heck
is a Protist?!?
Evolution of
the
Protistans
Diversity of the Protistans
Diversity of the Protistans
1. The Protozoans – animal like protists
2. The Slime Molds (Fungus-like Protists)
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Single-celled, animal-like eukaryotes
Free-living and parasitic in moist environments
Can reproduce sexually or asexually
Some famous Protozoans: Giardia and
Tyrpanosoma
Giardia lamblia trophozoites, as they appear with the scanning electron microscope.
Original image by Arturo Gonzalez, CINVESTAV, Mexico.
Diversity of the Protistans
Let’s Watch…
3. The Unicellular
Algae

Most are
components of
phytoplankton
(basis of food
webs; global
carbon sink!)
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Diversity of the Protistans
The Protistans: The Single-Celled Algae
Famous Single-Celled Algae: Red Tide, Pfiesteria
4. The Multicellular Algae
Three major groups:
1.
Red Algae
2.
Brown Algae
3.
Green Algae
You Try: Part 3
Source: www.redtide.whoi.edu; www.pfeisteria.org
Onto the Fungi:
Major
Characteristics
Next Up: Going Multicellular
and Heading for Land!
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You Try: Part 4
The Fungi: General Layout
HETEROTROPHIC
(use organic compounds for energy)
Can be SAPROBES (nutrients from
nonliving organic matter) or PARASITES
(extract nutrients from a living host)
EXTRACELLULAR DIGESTION
EUKARYOTIC
The Fungi: General Layout
5
The Zygomycetes
The Major
Fungi
Groups
Pilobolusdecomposes
animal dung!
Mycorrhizae
The Club Fungi
(Basidiomycetes)
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Fairy Rings
Mushrooms, shelf fungi, puffballs and
rusts
Important decomposers of wood and
plant material
Plant Pathogens!
WHY??
Incredible Fungal Growth:
Why Spores??
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Lichens: A Fungal Lifestyle
Lichens:
A Fungal
Lifestyle
What will life
on land be
like?!?
Thinking
About the
Plants…
The Bryophytes
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Mosses, liverworts and hornworts
Nonvascular plant (short!)
Dependent on moist habitat
Life Cycle of
a Typical
Moss
(Bryophyte)
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Drought-Tolerant Mosses
Many species of moss can survive drastic
plasmolysis. Rehydrated plants repair most
internal damage within minutes (drought
repair genes!). Respiration resumes in
minutes; photosynthesis resumes within 24
hours!
Scientists at the
USDA are eager
to learn more
about these
drought resistant
genes!
Seedless Vascular Plants:
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A Typical Fern Lifecycle
Whisk ferns,
lycophytes,
horsetails and ferns
Much larger (true
vascular tissues!)
Still dependent on
water for
reproduction
Which generation is
“dominant”? How does this
compare to the mosses??
The Beginning of a Trend?
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The Gymnosperms
“Naked Seeds”
3 Major Adaptations:
1.
2.
3.
Continued
reduction of
gametophyte
Evolution of the
seed
Evolution of pollen
Gymnosperms
Ovules and seed develop on the surface
of specialized leaves called scales
Arabidopsis thaliana pollen grains
Microscopy by Juergen Berger, computer
image manipulation by Heiko Schoof
The Seed
Into the Angiosperms!
OVULE
After
fertilization,
the ovule
develops into
a SEED.
Angiosperms: The Flowering Plants
Fruits are Mature Ovaries!
Fruits protect seeds and aid in their dispersal.
Ovary wall becomes the thickened wall of the
fruit.
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Quick Scavenger Hunt!
(In-Class, Part 1)

With your group,
find one example
of each of the
four major
groups!
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