Transcript Diversity

2.7 billion years ago, microbes invented
 Water
split to get H needed to turn CO2 into
sugars, O2 left behind
 All the iron on the surface rusted
 Oxygen accumulated
Organisms adapted to new world
 They
could get bigger; more efficient
Bigger, more complicated cells than
 Multicellular organisms developed
 Four kingdoms of eukaryotes currently
Fungi, the champion decomposers
Familiar terms: what do they mean exactly?
 Molds: types of fungi that grow as long
threads or filaments.
 When
Yeasts: another way fungi can look; oval,
unicellular in appearance.
 Some
they reproduce, they look different.
fungi can grow as yeasts or molds.
Mushrooms: these are reproductive
structures of certain types of fungi.
How do Fungi grow?
Fungi are heterotrophs
 They
are the great decomposers, break down
all kinds of polymers. Can destroy wood,
rubber, paint, all types of things.
 They are never photosynthetic!
Fungi grow into, through their food.
 They
release enzymes that break things down
 They take up resulting small molecules
 They grow at the tips and penetrate.
Fungi and plants
Some fungi are parasites
 Many
plant diseases are caused by fungi
 Fusarium, for example
Many fungi grow along with plants
 Myco
(fungi) rrhizae (roots) = mycorrhizae
 Fungi growing with plant roots help furnish the
plant with minerals from the soil
 Plants leak nutrients to feed fungi
 Both prosper
Fungi and humans
As decomposers, important in ecosystem
 Industrial
Some cause disease
 Athlete’s
foot, yeast infections, histoplasmosis
 Serious infections with diseases like AIDS
Source of important antibiotics
 Penicillium
is a fungus
Important in food and other industries
 Citric
acid, soy sauce, cheeses, mushrooms
How are they classified?
Once again, it’s about sex.
 Three main types of fungi
 When
two different mating types get together,
they make sexual spores
 The type of structure the spores are found in
determines the type of fungus
Mushroom is a type of spore-bearing structure
Fungi also reproduce asexually too
 They
make lots of spores this way, but not
involved in classification
Sexual reproductive structures that
Fungi make
Protista: one kingdom, or 8?
The Protists are unicellular eukaryotes
 For “pond scum” they show incredible
 Protists
were always lumped together by what
they aren’t.
 New schemes suggest grouping them into 8
or more different KINGDOMS
As different from each other as they are from
plants and animals.
Is there an easy way to learn about
the Protists?
Here’s one. Divide them into 3 groups:
Plant-like Protists
Contain chloroplasts
 Diatoms (right).
Diatomaceous earth = fossilized
diatoms: abrasives and slug
 Red,
brown, yellow algae
Seaweed, source of agar
 Dinoflagellates
Neurotoxins and red tide article.php/534.html
Animal-like protists
Capable of ingesting their food.
 Capable of moving around
 Amoebas
 Protozoa
with flagella or cilia
Disease-causing protists belong
to this group
 Diarrhea,
malaria, STD
Water molds
 Motile
by flagella (fungi aren’t.)
 Phytophora infestans, cause of
Irish potato blight
Slime molds
 “the
blob”, one giant cell or groups
of cells that crawl over the ground
 Digest everything in their path emia/SEMproj/phyinf_f.htm
The Kingdom Plantae
Plants are highly successful
 Photosynthetic, use sunlight energy and
carbon dioxide
 Also
need minerals to grow
The world of Plants
The most abundant and successful type of
plant are flowering plants, the Angiosperms.
 There’s actually 9 other completely different
types of plants.
 Mosses
 Ferns
 Cycads
 Conifers
(most evergreens w/ needles)
Examples: most primitive to most
 Have
no roots
 No seeds
 Produce
spores, not
 Naked
seeds, in cones
 Flowers
and seeds
Pictures cited
 arb02/moss.html
What have angiosperms got that
makes them good?
Specialized structures for pulling water out
of dry ground: roots
 Specialized structures for exchanging
gases with the atmosphere and collecting
sunlight: leaves
 Structures for holding the leaves up where
they can do these things: shoots
 Attract
pollinators that spread male gametes
(pollen, from anthers) to female gametes
(inside ovaries)
 Provide a protective place for embryo (within
seeds) to form.
Seeds are within or attached to fruit.
 Fruit
is a mechanism for dispersal of seed
 Some is eaten and excreted elsewhere
 Some sticks and is carried about
 Some blow, some float, many strategies