Exam 1 Flashcards
Taxonomy
A naming system
Phylogenetics
the study of evolutionary pattern
Phylogeny
a diagram of evolutionary relationships
Cladogram
phylogeny based on shared, derived characters
Monophyletic clade
a unique set of taxa unified on shared, derived characters
Phylogeny
evolutionary history of organisms
Node
common ancestor point where species diverge
Synapomorphy
Shared trait in two groups derived from common ancestor
Outgroup
Taxon that diverged prior to the taxa that are the focus of the study
Polytomy
Node that depicts an ancestral branch dividing into three or more descendant branches
Homology
similarity in organisms due to common ancestry
Monophyletic group
evolutionary unit that includes an ancestral population and all of its descendants
Homologous Trait
Similar trait in two organisms derived from a common ancestor
Homoplasy
- AKA Analagous Traits
- Similarity in organisms due to reasons other than common ancestry
Polyphyletic group
Unnatural group that does not include the most recent common ancestor
Analagous traits arise from _____________
- Convergent Evolution
- Evolution of a similar trait due to similar selection in each environment
Paraphyletic group
a group that includes an ancestral population and some of its descendents but not all
Parsimony
Minimizing of evolutionary changes in a tree
All members of bacteria and archea are _________ and _________
- Unicellular, prokaryotic
- prokaryotes lack membrane-bound nucleus
Prokaryotes are ________
Bacteria are ________
- paraphyletic
- monophyletic
________ is a major source of oxygen we breathe
Cyanobacteria
Prokaryotes outnumber human body cells __:__
10:1
Extremeophiles
- Bacteria or archaea that live in extreme habitats such as
- hydrothermal vents (hyperthermophile)
- ph<1 (acidophile)
- Saturated with salt (halophile)
Archea different from bacteria
- Archea have histones
- Archea don’t have peptidoglycan
Prokaryotes are (diploid/haploid)
Haploid
Prokaryotes replicate by
Fission (asexual)
Endospores
- Resistant to heat and dehydration
- Valuable in changing environment-nutrient deprivation
- Not readily killed by antimicrobial treatments
- anthrax
Transformation
DNA from environment
Transduction
DNA from virus
Conjugation
Transfer DNA from one bacteria to another by touch
Lateral gene transfer
DNA transfer within and among species
Locomotion of bacteria
Flagella and gliding
What do organisms need to survive
- Energy to drive metabolic processes
- Carbon for structural and storage molecules
Chemoorganotrophs
oxidize organic molecule via cellular respiration or fermentation
Chemolithotrophs
oxidize inorganic molecules
N2, Nitrate, ammonia
Phototrpohs
use light energy to make ATP
Autotrophs
Manufacture their own carbon containing compounds
Heterotrophs
Live by consuming autotrophs
Source of metabolic diversity
lateral gene transfer
Germ Theory
- Bacteria cause infectious diseases
- Many gram-positive bacteria cause disease
Koch’s postulates
- microbe is present in sick individuals and absent from healthy
- Microbe must be cultured out of the host
- Injection of microbe in healthy individuals causes them to be sick
- Microbe must be isolated from the newly sick individual, cultured, and shown to be identical to original microbe
Germ theory of disease
- Pattern: some diseases are infections
- PRocess: transmission and growth of a certain bacteria and viruses
_______ laid foundation for modern medicine
- germ theory of disease
- greatest impact initially was on sanitation
antibiotics
molecules that kill bacteria
Bioremediation
- pollutant degradation via microbes
- Bacterial remediation: metabolizes pollutants
Ancient atmosphere—> modern atmosphere
N2, CO2—–> N2, CO2, O2
Cyanobacteria
- Photosynthetic
- first to perform oxygenic photosynthesis
Nitrogen fixation
N2—>NH3
Purpose of enrichment cultures
isolate and characterize new bacteria and archaea
Direct sequencing
- collect sample
- isolate dna
- amplify bacteria dna
- sequence specific genes
Metagenomics
Compare dna fragments and sequences with known genes
metagenomic analysis allows biologists to:
identify and characterize organisms that have never been seen
What are protists
eukaryotes that are not fungi, plants or animals
Eukaryotic synapomorphies
- nucleus w/ an endomembrane system
- nuclear envelope
- ER
- Mitochondria
- Cytoskeleton
General protist characteristics
- No peptidoglycans in cell wall
- many unicellular some multicellular
- sexual/asexual
- DNA is linear and has histones
What enables protists to be larger
- Organelles
- Compartmentalize function
- increase surface area
Protists are a ________ group
paraphyletic
1 flagella
amoebozoa, fungi/animals
two flagella
- Excavata
- plantae
- rhizaria
- alveolata
- stramenopila
Organelle evolution
mitochondria and chloroplasts
endosymbiotic theory
- an anaeroic eukaryotic cell engulfs aerobic prokaryotic cell
- prokaryote is not digested
- mutualism begins
Evidence for endosymbiotic theory
- Processes observed today likely happened in the past
- endosymbiotic orgs
- anaerobic protists ingest bacteria
- observations about mitochondrial structure
- similar size and organization
- have own dna and ribosimes
- replicate by fission
Primary endosymbiosis started w/
Plantae ( red algae, green algae, land plants)
_______ causes malaria
- plasmodium
- economic effects
Plasmodium
- alveolata (apicomplexa)
- Unicellular
- intracellular
- obligate parasite
- asexual/sexual
life cycle
sequence of developmental events occurring as an individual grows and reproduces
complex life cycle
development occurs in >1 habitat
Brown Algae
- Clade: stramenopila
- characterized by
- unique photosynthetic pigments
- cell walls containing cellulose
- marine
- multicellular
- sessile/floating mats
sargasso sea consists of
vast mats of brown algae
brown algae reproduction
- not complex life cycle
- alternation of generations
- multicellular gametophyte: haploid, makes gametes
- multicellular sporophyte: diploid, makes spores
Marine carbon cycle
how might promoting phytoplankton blooms affect atmospheric CO2
They are primary producers so would absorb the CO2 and convert it to oxygen, lowering atmospheric CO2
Diatoms
- Clade: stramenopila
- Characterized by: silicon-rich shells w/ box and lid
- fresh and marine habitats
- inicellular-chains
- photosynthetic
- passive/gliding
diatom reproduction
- diploid-dominant
- no alt. of gen
- not complex
- sexual/asexual
How to ID protists
direct sequencing/metagenomics
Model organism
- dictyostelium discoideum
- cellular slime mold (amobozoa)
- characterized by: no cell wall and amorphous shape
- soil-living
- eat detritus
phagocytosis
- ingestion of bacteria or other material
- model org
- amoeboid movement
cellular slime mold reproduction
- Dictyostelium discoideum
- haploid-dominant
- sexual/asexual
- not complex
how the model org moves
slug formation
fungal characteristics
- eukaryotes
- multicellular
- cell walls w/ chitin
- heterotrophs
- terrestrial/aquatic
animals and fungi
- synthesize chitin
- flagella in chytrid spores and similar gametes to animals
- store food as glycogen
fungal bodies come in two forms
- yeasts
- mycelia
mycelia specialized for _______
feeding
mycelia composed of _____
- hyphae
- filamentous and branching
- haploid and heterokaryotic
- compartmentalized by septa
mycelia secrete ________
digestive enzymes
mycelia have high ________
surface area to volume ratio
fungal reproductive structure
- thick and flishy
- does not absorb food
chitrids
swimming gametes and spores
zygomycetes
zygosporangia: spore-producing structures formed when hyphae are yoked
basidia
club shaped cells where meiosis occurs and 4 spores form
ascomycetes
asci: sac-like cells where meiosis occurs and 8 spores form
fungal taxonomy
- based on dna sequence data
- work in progress
- polytomy
Ascomycota
- Sac fungi
- monophyletic
- distinguished by asci (sac-like spore producing structure)
ascomycota are _________
- non-lichen formers
- saprophytic
- parasitic
- some are ectomycorrhiza
ectomycorrhiza
form mutualism with roots of plants
lichen is
- cyanobacteria + ascomycota
- major food for caribou
- participate in soil production from rocks
basidiomycota
- club fungi
- monophyletic
- parasitic: rusts and smuts
- saprophytic
- ectomycorrhizal
- can be source of food/medicine
basidiomycota reproduction
- distinguished by spore formation in basidia
- asexual
- sexual
zygomycota
- parasitic Rhizopus
- saprophytic
- predatory
- some steroids/antibiotics
saprophytic
an organism that eats dead or decaying material
zygomycota reproduction
- distinguished by zygosporangia
- haploid hyphae yoke together
- sexual reproduction common
