Basics of Life and Introduction to Ecology

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Basics of Life andIntroduction to Ecology

• September 20, 2007

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Organic Molecules

• Carbohydrates
• C, H, O
• Used for energy storage or structural
• Proteins
• Made up of amino acids
• Enzymes, structural, hormones, etc.
• Lipids
• Include Fats and Oils
• Hydrophobic
• Nucleic Acids
• Made up of nucleotides
• Genetic material

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Photosynthesis
6 CO2 6 H2O
6 O2 C6H12O6
sunlight
- Carbon Fixation
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• Autotrophs
• phototrophs
• chemotrophs
• Heterotrophs
• bacterivores
• herbivores
• carnivores
• scavengers

http//www.canadiangeographic.ca/atlas/glossary.as
px?alphahid136langFr
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Respiration
6 CO2 6 H2O energy
6 O2 C6H12O6
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Primary Production

• Gross vs. Net Primary Production
• What is needed for primary production?
• sunlight (except for a few cases)
• carbon dioxide
• nutrients
• Nitrate
• Phosphate
• Micronutrients (Iron, etc.)

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Decomposition

• How do nutrients get returned to the ocean?

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Cells

• What is a cell?
• What are the parts of a cell?
• Membrane
• Organelles
• Nucleus
• Mitochondria
• Chloroplast

Prokaryotes
Eukaryotes
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Types of Organisms
Multicellular
Unicellular
http//www.oceanexplorer.noaa.gov/explorations
www.nsf.gov/od/lpa/news/03/pr03106_images.htm
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Types of Reproduction

• Asexual
• Cell division
• Creates clones
• Sexual
• Requires the union of two separate cells
• Gametes
• eggs
• sperm

http//ghr.nlm.nih.gov/handbook/illustrations/mito
sismeiosis.jpg
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Tree of Life
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Phylogeny

• Grouping things based on how closely they are
  related

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Taxonomy - Classification of Life
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Marine Organisms

• Pelagic Organisms
• Plankton
• Phytoplankton
• Zooplankton
• Nekton
• Benthic Organisms
• Sessile
• Motile

http//www.ocean.com/resource.asp?locationid5res
ourceid5581ProdIdCatId132TabIDSubTabID
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Ecology

• A branch of biology which studies how organisms
  interact with each other and their habitats
• Habitat the natural environment in which an
  organism lives
• Ecology considers both abiotic and biotic
  factors

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Levels of Organization

• Ecosystem
• Community
• Population
• Individual
• Cell
• Organelle
• Molecule
• Atom

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Population Growth

• How do populations grow?
• Reproduction
• Asexual
• Sexual

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Population Dynamics

• Populations tend to be self-regulating
• Grow until they reach a carrying capacity
• Population growth and carrying capacity
  determined by limiting resource

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Limitations on Population Growth

• Resources
• Competition
• Predation

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Competition

• Interspecific/Intraspecific Competition
• Types of Competition
• Interference Competition (Direct)
• Exploitative Competition (Indirect)

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Avoiding Competition

• Resource Partitioning
• Ecological Niche
• Hutchinsons Paradox of the Plankton
• How are there so many species of plankton in a
  seemingly homogeneous environment?

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Predator/Prey Interactions

• Avoiding Predation
• Physiological Defenses
• Example Spines on phytoplankton
• Behavior
• Example Diel vertical migration
• Trophic Levels
• Transfer of Energy/Biomass

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Food Chains vs. Food Webs
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Trophic Interactions

• Bottom-Up Controlled Ecosystem
• Example Iron fertilization experiment
• Top-Down Controlled Ecosystem
• Example Fishing

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Trophic Cascade
Sea Otters
Humans
Sea Urchins
Trophic Cascade A chain-reaction within food
webs that results from changing population
densities at higher trophic levels (see below),
shifting the dominance and impact of consumers in
lower levels.
Kelp