Lecture 10

What's the Koeppen System?

Maps that specifically tell us the climate of different regions in the world

What are Prochlorococcus?

Smallest photosynthetic organism on the planet, responsible for 50% of atmospheric O2

large surface area: good at obtaining nutrients

there are high concentrations of it in the middle of the ocean (gyres)

What is the phylogeny of plants?

1. Sister group of green algae
2. Bryophytes (LAND PLANTS)

* Liverworts 
* Mosses
* Hornworrts


3. Vascular Plants (LAND PLANTS)

* Lycophytes
* Ferms and horsetails
* Gymnosperms
* Angiosperms

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They’re all common ancestors

What are green algae?

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* Range from the tiniest unicellular photosynthetic organisms to the giant kelp
* Live entirely in the water

What are phytoplankton?

Are phototrophic autotrophs of the oceans, mostly unicellular

its distribution by species are always dependent on nutrient supply

What is the difference between plankton,

nekton, benthos?

Plankton: at the mercy of the currents

Nekton: anything that moves independently of the currents

Benthos: anything on the sea floor

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What are some types of phytoplankton that with low and high nutrients?

Low nutrients water:

* Cynaboacteria (mainly prochlorococcus)

High nutrient water:

* Dinoflagellates
* Diatoms
* Coccolithophores

What are diatoms: big and greedy?

20-200 microns

Use silica (sustains its) for protection

Regions w/high nutrient concentrations 

Small surface area to volume ration:

need extra work at getting nutrients but need lots of them

What are coccolithophores?

* Armored but fragile beauties


* 5-100 microns size smaller than diatoms 
* CaCO3 tests (deposit chalk)
* They prefer water with high nutrient concentrations

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What are dinoflagellates?

Pesky (annoying) but important 

* Have flagella
* Very diverse
* Common endosymbionts 
* Can have toxins, be bioluminescent
* Common in “red-tide” events 
* Produce toxins, ingested by shellfish in large quantities

What are red-tides?

contain

* high concentrations of phytoplankton, often dinoflagellates
* have toxin-producing algae (harmful algal blooms)

Examples of toxins include:

* Saxitoxin causes paralytic shellfish poisoning
* Brevetoxin can be aerosolized, causing respiratory problems

Climate regulation

1. Marine Phytoplankton produce DMS gas 

which is Oxidized in the atmosphere to sulfur-base aerosols

* Phytoplankton to gas (positive more cloud condensation)
* DMS gas to CNNs postive 

Aeroles become cloud condensation nuclei (CCNs) responsible for cloud seeding

* CCN to albedo positive

Albedo to phytoplankton negative

Clouds impact albeldo which has a cooling effect (negative)

What are bryophytes? (THE AMPHIBIANS OF THE PLANT WORLD)

First Land Plants aka mosses do not have roots which they requires lots of water

Rely on other structures to be sustained

Limited by water loss (desiccation) 

Low-growing

Can withstand long periods w/out water, but eventually DIE

What are vascular plants?

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1. Contains vascular tissues (xylem and phloem) distrubute resources (water nutrients, sugar) through the plant


2. “Alternation of generation reproduction

What were the first to evolve of vascular plants?

1. Lycophytes (single vein)

Hb the second ones?

1. Ferns and Horsetails (spores)

The third one?

1. Gymnosperms “naked seed” first-seeded plants

* Rely on animals and wind for seed dispersal

Examples: Cycads, Ginkgos (fossils) trees, Conifers(trees that bear their seeds in cones)

What about the 4th one?

Angiosperms = “Protected Seeds”

* 90% of the species of land plants present today


1. Contain Flowers!
2. Encase seeds in
protective coat (i.e. a
fruit)
3. Co-evolved w/insects
4. Flowers attract a pollinator, rewards plants & animals seed/pollen dispersal

Why are angiosperms successful?

Efficient at building their bodies & completing their life cycle

Reproduce quickly & with minimum of resources

What contributes to angiosperm diversity?

the interaction of flowers and animal pollinators

What is the anatomy of a vascular plant?

Shoot

* Very Top: Reproductive organs
* Leaf
* End: Stem

Roots very bottom

What are shoots made of?

Repeating units of nodes and internodes; one or more leaves attached at each node

What is shoot apical meristem & where is it?

Site of new cell division

tip of shoots

What is primary growth?

Plants grow up, then out

What do all vascular plants have?

LEAVES which are:

* Sites of photosynthesis
* Serve as a way for plants to climb/reach sunlight
* Protection
* Trap nutrients