What is Algology (phycology):
Algoloy is the science (gr. logos) of algae (L.
algae).
Phycology is the science (gr. logos) of algae
(gr. phycos). This discipline deals with the
morphology, taxonomy, phylogeny, biology,
and ecology of algae in all ecosystems
3.5 billion yrs ago
Cyanobacteria—first algae
Prokaryotes—lack membrane bound organelles
Later eukaryotes evolved—mitochondria,
chloroplasts, and chromosomes containing DNA.
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Binomial nomenclature—Ulva lactuca
Binomial Nomenclature was proposed by Linnaeus
in 1753. Cited in Species Plantarum.
 Type Specimen—The specimen from where the
description is made. Collected and placed in a
herbarium. Herbarium label—species name, location,
date of collection, habitat, name of collector and
identifier)
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How are algae similar to higher plants?
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How are algae different from higher plants?
 Presence of cell wall—mostly cellulosic.
 Autotrophs/Primary producers—carry
out photosynthesis
 Presence of chlorophyll a
Algae lack the roots, stems, leaves, and other
structures typical of true plants.
 Algae do not have vascular tissues—non vascular
plants
 Algae do not form embryos within protective
coverings—all cells are fertile.
 Variations in pigments.
 Variations in cell structure—unicellular, colonial and
multicellular forms.
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Chlorophylls (green)
Carotenoids (brown, yellow or red)
Phycobilins (red pigment-phycoerythrin
blue pigment –phycocyanin)
Kelp forest up to 50 m high are the marine
equivalent to terrestrial forest; mainly built by brown
algae
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Some algae
encrust with
carbonate, building
reef-like structures;
cyanobacteria can
from rock-like
structures in warm
tidal areas:
stromatolites
Small algae live on top of larger algae:
epiphyton
• Algae in free water: phytoplankton
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Algae have adapted to life on land and occur as
cryptobiotic crusts in desert and grassland soils
or endocryptolithis algae in rocks
Algae live on the snow cover of glaciers and in the brine
channels of sea ice
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A symbiosis of algae and fungi produced the lichens,
which are pioneer plants, help convert rock into soil
by excreting acids, stabilize desert soil, are sensitive
to air pollution
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Algae can cover trees or buildings green or live in the
hollow hairs of ice bears
Algae can be so dominant that they discolor the water
Higher amounts of nutrients are usually the cause
Algal blooms can have harmful effects on life and
ecosystem:
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 Reduced water clarity causes benthic communities (see grass) to die
off
 Fish kills are common effects
 50% of algal blooms produce toxins harmful to other organisms,
including humans
 Algal blooms produce a shift in food web structure and species
composition
Algal blooms can mostly be linked to sewage input or
agricultural activities, leading to nutrient pollution:
eutrophication
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Unicells: single cells, motile or nonmotile
Colonies: Assemblage of individual cells with
variable or constant number of cells that remain
constant throughout the colony life
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Coenobium: Colony with constant number of cells,
which cannot survive alone; specific „tasks“ among
groups of cells is common
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Filaments: daughter cells remain attached after cell
division and form a cell chain; adjacent cells share cell
wall (distinguish them from linear colonies!); maybe
unbranched or branched
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Siphonaceaous forms: one large, multinucleate cell
without cross walls
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Parenchymatous and pseudoparenchymatous
algae:
mostly macro-scopic algae with tissue of
undifferentiated cells and growth originating from
a meristem with cell division in three dimensions;
pseudoparenchymatous superficially ressemble
parenchyma but are composed of appressed
filaments
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SexualGametes
Vegetative
Cell
divisions/Fragmentation
=part of the filament
breaks off from the rest
and forms a new one.
Asexual Reproduction
Zoospores after losing their flagella,
form new filaments. No sexual fusion.
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ISOGAMY-Both gametes have flagella and similar in size and morphology.
ANISOGAMY-Gametes have flagella but are dissimilar in shape and size. One gamete
is distinctly smaller than the other one.
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OOGAMY-gamete with flagella (sperm) fuses with a larger, non flagellated gamete
(egg).
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Group
Mitochondrial cristae
Plastid origin(s)
Red algae (Rhodophyta)
flattened
primary
Green algae (Chlorophyta)
flattened
primary
Cryptomonads
(Cryptophyta)
flattened
secondary (red)
Euglenoids (Euglenophyta)
disk-shaped
secondary (green)
Haptophytes (Haptophyta)
tubular
secondary (red)
Dinoflagellates (Dinophyta)
tubular
mainly tertiary (various
sources)
Ochrophytes (Ochrophyta)
tubular
secondary (red)
Cyanobacteria
Purple nonsulfur bacteria
Oil is very important
fossil fuels comes from
diatom remains.
The energy we extract
from fossil fuels was
originally stored in
organisms through the
process of
photosynthesis.
Why wait millions of
years?