Download Help for quiz 2 – Biology 130 Summer 2011 Chapter 5 – The

Help for quiz 2 – Biology 130 Summer 2011
Chapter 5 – The Microbial World
The order of events to get to the first cellular organism:
Spontaneous or abiotically “created” molecules
Spontaneous polymerization of random polymers
Polymers can influence subsequent reactions by acting as a catalyst
Polymers with a crucial property: the ability to catalyze reactions that lead to the
production of more molecules of itself by complementary templating
Ribozymes
Family of mutually supportive catalytic RNA molecules.
One catalyzes the reproduction of the others
Proteins with much greater catalytic capabilities
The development of an outer membrane was a crucial event
DNA replaces RNA as the genetic blueprint
The order of events to get from prokaryotes to animal eukaryotes and plant
eukaryotes.
The first anaerobic bacteria
Food shortage
Photosynthetic bacteria
Oxygen in the atmosphere
Bacteria capable of anerobic respiration
Endosymbiosis (engulfing of another organism)
Leads to eucaryotic cells with distinct organelles
Origin of animal eukaryotic cell
Origin of plant eukaryotic cell
Prokaryotes
• Archea and Bacteria
• Characteristics of Archean and Bacterial Cells:
– Prokaryotic- no nucleus
– Single chromosome Most with cell wall
– Great metabolic diversity (they do more than just breathe oxygen)
–
Dissolved organic carbon in the ocean
•Forms polymers and particles (snow) that are the habitat for many prokaryotes in
the water column
Phytoplankton
•Unicellular algae and cyanobacterial component of the plankton
•50% of global photosynthesis
•Some major algal groups
–Diatoms
–Dinoflagellates
–coccolithophores
Diatoms
–Photosynthetic
–Yellow-brown color in life is a result of photosynthetic pigments
–Shell of silica called a frustule
–Most important primary producer on Earth
–Most are planktonic
–Store excess energy as an oil which also aids in buoyancy
Dinoflagellates
– Most species live in marine environment
– Mostly photosynthetic, some can ingest particles
– Each species has unique shape reinforced by plates of polysaccharide (like
cellulose/wood)
– flagella produce motion
– Some are bioluminescent
– dinoflagellates live in a symbiotic relationship with corals, sea anemones
and other organisms
– Some dinoflagellates produce very serious toxins.
Coccolithophores
•
•
Ornate shells of calcium carbonate
Are very important in removing CO2 from the atmosphere that
sinks to the seafloor when coccolithophores die.
Chapter 6 Marine Plants
Marine Macroalgae
These algae are called by a generic term “seaweeds” or more formal term
macroalgae
algae do not have the same advanced structures seen in plants such as roots, stems
and leaves
The body of a macroalgae is known as a thallus.
This thallus can be simple or more advanced in its structure.
In some algae, there are:
Blades – leaf-like structures
Stipes – stem-like structures
Holdfast – root-like structures
(these structures lack the advanced conducting tissues seen in true plants)
Can exhibit extremely fast growth rates
Important habitat and food source of other marine organisms.
Three general types based on photosynthetic pigments: green, red, and brown.
Seagrasses (a true plant)
They also provide habitat for countless organisms that hide among the blades in
seagrass beds (large collections of seagrass plants)
Eelgrass is widely distributed in shallow water bays and estuaries.
Salt marsh Plants- plants bordering shallow bays and tidal creeks.
Cordgrass, Spartina, the predominant salt marsh plant is in the grass family.
Spartina is extremely important as habitat to young marine animals such as
juvenile invertebrates and fish.
Chapter 7
Marine Animals Without a Backbone
Invertebrates
•Animals without a backbone are known as invertebrates. Those with a backbone are
called vertebrates.
•About 97% of animals are invertebrates.
•All major animal groups have representatives in the marine community.
Burgess shale fossils
Mudslide on the british Columbia continental shelf preserved soft bodied
invertebrates from right after the Cambrian era
•Many body plans are now extinct
•Only one chordate fossil found
•In theory if evolution was “replayed” we may not have the same organisms that
exist today.
Choanoflagellates
Can form colony
Have long been considered to be the common ancestor of multicellular animals
•Porifera: The Sponges
•Characteristics of Phylum:
–All sponges are sessile (non-motile and living attached)
–This water movement is required to allow sponges to filter feed (a type of
suspension feeding) on plankton and dissolved organic matter in the water.
–Sponges do not necessarily have any body symmetry. This is the only phylum
that is not symmetric as a general rule
Cnidarians: Stinging animals
•Characteristics of Phylum:
–Radial symmetry
–Mostly marine organisms
–Two
body forms exist :
•Medusa – free floating form which is transported by water currents,
mouth with surrounding tentacles are positioned downward
•Polyp – sessile, attached form with mouth and tentacles are positioned
upward
–stinging cells located on tentacles. These are used for protection and for
feeding
•Jellyfish lake Palau – non-stinging jellyfish with symbiotic algae
Upside down jellyfish Cassiopea – also relies on photosynthetic symbiotic
algae
•
•Ctenophores – also known as comb jellies
•Characteristics of Phylum:
–all marine
–rows of thick cilia that beat continuously
–Long sticky tentacles used to capture prey voracious predators