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concept map, Classification and Systematics (Levels of Taxonomic…
concept map
Classification and Systematics
Understanding cladograms
cladogram
node
represent the divergence of one taxon into two
apomorphy
a feature present in one or several derived members of a group, but not present in the ancestral members
all of the branches that lead from it constitute a clade.
uninformative
common ancestor
extend from any particular point
paraphyletic groups
one that does not contain all the descendants of the most common ancestor
diagram that shows evolutionary patterns by means of series of branches.
clade
any ancestor (node) & all of the branches that lead from it
Cladograms and taxonomic categories
basal angiosperm.
living descendants of those early-diverging clades
eg: angiosperms are either monocot or dicot.
species that can interbreed.
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taxonomic studies
isotype specimen
a specimen obtained from the same plant/clone as the type specimen
type specimen
a single specimen that is the absolute standard for the species & its scientific name
Levels of Taxonomic Categories
. :red_cross:
Genera
critical concern
genera are natural
all common ancestor are in same genus.
Monophyletic group
all species include genus
related to eachother by common ancesor.
members evolved from different ancestor
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Polyphyletic group
singular genus
closely related species grouped together
Family
well defined , with widespread
above genus
composed of one, several or often many genera.
level above family are order, class, division and kingdom
Scientific names
can be traced directly to Carolus Linnaeus
inheritance of acquired characteristics
all cells of the body produce fluids
Species
specie refers to the money,
not predictable
can interbreed with eachother.
most fundamental level of classification.
binomial system of nomenclature
every species have had both number of genus name and a species epithet
Other type of classification system.
Classification systems of fossils
to identify both its ancestors and its relatives that might have later evolved in the species.
form genera all fossils with the same basic form or structure classified together.
goal is to understand the evolution of the fossil
third type of classification used for fossil organisms.
Artificial systems of classification
follow the organic history of the organisms.
goal is to identify plant by means of obvious characters such as flower color and plant habitat.
key characters
easy to observe
only used as adjuncts to natural systems.
Cladistics
synapmorphies
common ancestral group.
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or homologous feature.
descended from common ancestor.
complicated by the fact that plants can resemble each other for 2 distinct reasons
they have undergone convergent evolution.
method of analyzing these photogenic evolutionary relationships
Concepts :check:
systematics
understand each of these evolutionary lines
Taxonomist
adopted goals at the end of 19th century,
assigning plants name on the basis of phylogenetic relationships.
Natural system of classification.
scientist who specialize in classification and naming
Phylogeny
hereditay relationships of any group of organisms
nomenclature
reflects the relationship.
major lines of evolution.
grade classification
based on levels of evolutionary advancement
kingdom Plantae
established clade of true plants
ex: protistans were placed together bc they had low lvl (low grade) of evolutionary advancement
Chapter 19:Algae and the Origin of Eukaryotic Cells
concepts
Origin of Eukaryotic Cells
Organelles
Ribosomes
80S
Dictyosomes
Mitochondria
Plastids
In plants and algae
Flagella & Cilia
9+2 arrangement of microtubules
Nucleus
Vacuoles
Vesicles
Endoplasmic Reticulum
Origin of Mitochondria and Plastids: The Endosymbiont Theory
Endosymbiont Theory
Revived in the 1960s
Speculated that plastids & mitochondia are prokaryotes in eukaryotes.
Found by KC Mereschkowsky
Origin of Mitochondria
Prokaryote was engulfed by a Eukaryote
Prokaryote evolved to have some eukaryotic species.
Hetertrophic
Nuclear Envelope
80S ribosomes
Origin of Plastids
Heterokonts
Gave rise to diatoms, brown algae, etc.
Two flagella of different types
Smooth
Hairy
Early Eukaryotes
Prochloron
First prochlorophyte
Primary Endosymbiosis
Gave rise to a clade containing red, and green algae
Arise similarly to mitochondria
Secondary Endosymbiosis
Produced other lines of Algae
Engulfed partner would’ve been photosynthetic
Types of Cytokinesis
Several types occur in Algae
Phycoplast
May be associated with division
Microtubules oriented parallel to the plane where the new wall will form.
Autogenous Theory
Prokaryotes eventually became more complex, and became eukaryotes
DNA Structure
Many genes contain introns
More elaborately packaged than in prokaryotes
Forming Chromosomes
Nucleosome Histones
DNA molecule carries thousands of genes
Nuclear Structure and Division
Quite sophisticated
Contains most of the DNA
Contains Nucleolus
Typically Haploid or Diploid
Eukaryote= True Nucleus
Characteristics of Various Groups of Algae
Lines Resulted from the secondary endosymbiosis of plastids.
Green Algae
Red Algae
Green Algae
Body Construction in Green Algae
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Nonmotile Colonies
Cells lose flagella or never develop them
Coenocytic Body
Acetabularia
Karyokinesis occurs without cytokinesis, and giant multinucleate cells result.
aka Siphonous Body
Motile Colonies
All cells are similar
None is particularly specialized
Cells adhere loosely
Membranous Body
Orientation of cell divisions is controlled precisely such that all new walls occur in only two planes.
Parenchymatous Body
Bulky-Three dimensional
Cell division occurs rapidly in all three planes
Cells are interconnected by plasmodesmata
Filamentous Body
Holdfast
Attaches filaments to a rock
Cells are held tightly by a middle lamella
Life Cycles of Green Algae
Monobiontic Species
Specialization occurs in that only one free-living generation exists.
Alternation of Isomorphic Generations
Gametophyte & Sporophyte resemble strongly
Oogamy
Anisogamy
Slight differences in Gametes
Evolved Later
Dibiontic
Alternation of generations between haploid and diploid
Alternation of Heteromorphic Generations
Gametophyte and Sporophye are very different
Isogamous
Identical
Representative Genera of Green Algae
Parenchymatous Species
Chara
Sister group to the embryophyte clade
Multicellular reproductive structures
Charophytes
Undergo cell division by means of a phragmoplast
Filamentous Species
Conjugation
Undergone by Haploid filaments
Zoospores
Grow into new filaments
Members of Genus
Ulothrix
Isogamous
Monobiontic life cycle
Haploid
Unicellular Species
Chlamydomonas
Simplest chlorophytes
Two anterior flagella
Has chlorophyll
a
and
b
Motile Colonial Species
Gonium
Each colony contains only a few cells
Flagella beat in coordination
Zygote divides
Progeny cells are held together by gelatinous matrix
Coenocytic Species
Dibiontic life cycle
Laminar Species
Ulva
Almost identical to
Ulothrix
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Dividing cells form sheets
Haploid
Quadriflagellate
Green Algae and Embryophytes
Streptophytes
Monophyletic clade of:
Embryophytes
Charophytes
Archaeplastids
aka Primoplantae
Names suggested for the clade of:
Green Algae
Red Algae
Embryophytes
Red Algae )
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Agar
Floridean Starch
Occurs in cytoplasm as granules
Excess photosynthate
Branched polymer of glucose
Pit Connections
In the walls of algae
Large group of especially distinct algae
Poorly known-life Cycle
dinoflagelet
Oomycetes
Severe Plant Pathogens:
Phytophthora infestans
Disease of potatoes
Cause of Irish potato famine
Plasmopara viticola
Disease of grapes
Most are aquatic
Diverse in structure and nutrition
Mostly sexual reproduction
Lack cholorplasts
Must be parasitic or saprophytic
Red Tide )
So numerous that the water is reddish
No histones
Typical spindle does not form
Almost exclusively motile and unicellular
Nuclear envelope and nucleolus persist throughout mitosis
Chromosomes are permanently condensed
Euglena
The majority never have chloroplasts
Many features have undergone little change
Most are unicellular
None reproduce sexually
Brown algae and their relatives
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Diatoms
Diatomaceous Earth
Deposits of Siliceous Frustules
Clade of heterokont
Distinctive morphology
Yellow-Green Algae
Contain chloropyll
c
Vaucheria
Long tubular coenocyte
Large central vacuole
Tribonema
Occur mostly in fresh water
Brown Algae
All multicellular
Receptacles
Ends of Branches
Swollen with large deposits of hydrophilic compounds
Trumpet Cells
Resemble sieve tube members
Carry-out long-distance transport of carbohydrates
Conceptacles
Some undergo meiosis
Small cavities
Cell walls contain cellulose and alginic acid
Almost exclusively marine
Grow in the Littoral Zone
Region between low & high tide
Laminarin
Constitutes up to 34% of the body weight
Storage product
Golden-Brown Algae
Almost always have flagella
Either uniflagellate or biflagellate
Coccolithophorids
aka Coccoliths
Do not decompose
Relatively inert
Develop within special vesicles in the ER
Single cells covered with numerous tiny siliceous scales
