Midterm 2 (Part 1) Flashcards
Transduction of bacteria?
exchange dna thru bacteriophage, attactches to cell and inserts dna, cell replicates phages and spreads, intermidtae between donor and recipient cell
what are fimbriae and capsule?
f- short appendages to help bacteria adhere
c- polysaccharide surrounding cell wall, protects
Biozone?
intervals of geological strata
what is R plasmid?
resistance plasmid that contains antibiotic resistence genes plus genes for coding pillus
microbiome?
community of microorganisms that live on or in body
Stanley millers experiement?
mimiked early earth atmosphere, several organic compounds (amino acids, hydrocarbons) could be formed spontaneously (through abiogenesis) from abiotic molecules
What happened in cambrain explosion
posterior appendages for movement, anterior predation appendages, anterior sensing organs (NS), bilateral symmentry
Organisms can…
undergo rapid morphological changes
Domain of eukarya?
11 000 000 est, serial endosymbiosis, evolved from prokarotes in arkea, posses mitochondria, plastid, cell gained new metabolic system
role 2?
assimilating minerals into biomass on upper trophic level, can decompose and aborb nutrients from dead organic material (recycle C, H, N, O,P)
Cambrian explosion
Around 530 million years ago, a wide variety of animals burst onto the evolutionary scene
Domain of archea?
est. 50 000 species, prokaryote but not bacteria, extremophiles, many are methanogens, source of DNA polymerase
What molecules are abundant in earth?
C, O, H, N make most molecules like carbs, proteins, fatty acids, nucleic acids
2 roles of prokaryotes in ecosystem?
absorbing energy, assimilating minerals
what makes a good biomarker?
lived for short time and have specific ecologicalo requirement are good fro dating of rocks
conjugation of bacteria?
bacteria from same species donate dna,
1. pillus draws reciver cell closer
2. mating bridge
3. plasmid transferred
What do we know about Foraminifera?
wide distribution, specific habitats, preserved by calcium carbonate shell
what can cause discontinuity in fossil record
erosion, tectonic plates, changes in climate, colonization, extinction, etc
Inorganic/organic compunds?
o- glucose, lipids
i- CO2, HCO3
what is a protocell?
precursor to modern living cells, droplet with membranes for selective permeability, werent living organisms
how do bacteria show resistance?
genetic variation from. mutations, trasnitted heretibility, only resistant selective strains grow
features of prokaryotes?
0.5-5 um, membrane, cytoplasm with only cytosol, no nucleus, no organelles
what is selfhish DNA
dna that enhances its own transmission
What is the burgess shale
patenlogical site in BC, lots of fossils, benthic (on sediment), endobenthic(in sediment), nektonic(swimming)
role 1 of prokaryotes in ecosystem ?
absorbing energy, photoautotroph can convert CO2 to sugar, produce O2, fix atmospheric N2
what is LUCA
all living organisms synthesize L optical isomers of amino acids, genetic code, almost universal, LUCA was last universal common ancestor
Nutritonal requirements?
phototroph- photoautotroph (i) or photoheterotroph (o)
chemotroph- chemoautotroph (i) lithotroph or chemoheterotroph (o) organotroph
how did we get from molecules to proto cells? (4)
1- abiotic synthesis of organic molec.
2-polymerization to macromolec.
3-packaged into protocell
4- transmission of self replicating molecules
symbiosis hypothesis
cells from diff species establish a mutually beneficial and long term association
Faunal succession?
specific vertical sequence of fossilized fauna/flora, identifed over wide horizontal distance
What is biostratigraphy
determination of relative age of sedimentary rocks
prokaryotes considered what
paraphyletic group, common ancestor and some desendnets
What is adaptive radiations?
a rapid increase in the number of species with a common ancestor, allowing to fill different ecological roles (Darwin Finches)
What came first DNA or RNA
RNA (ribozymes) function as enxymes/catalysts, can self replicate
phases of binary fission?
lag phase (sysnthesis of components), log phase (rapid growth), stationary phase (population stops growth), death phase ( loss due to lack of nutrients)
What does natural selection favor?
RNA molecules that self replicate faster, splitting to daughter vesicle is inheritence
what did LTEE show?
populations adapted and grew over time, new mutations, bacteria evolve rapidly
Why are virsuses not organisms?
No cell organization, metablosim, or growth
What 7 properties do all organisms share?
Cell organization, energy, reproduction, evolution, growth, homeostatsis, response to stimuli
commensalism?
symbiotic relationship where organism benefit, other is not help or harmed
Effects of bacteria
can cause infect. diseases, also help digestion, immunity, protection against infections, provide vitamins
What is a stromatolite?
layered rock from activites of photosynthetic prokarates that binds films of sediment
Example of mass extinctions?
permian, palogene extinction
colonial hypothesis?
colonies form through cooperation of unicellular orgainsms of same species, by fail to seperate
what is radiometric dating
determination of abosulte age, uses isotope compisition of orgainsms on way to fossils or magmatic rock
What is needed for formation of molecules?
precursor molecules, thermal energy, catalysts
transformation of bacteria?
release dna after cell death, taken back up by other cells, new strain carries plasmid
12 C isotope vs 14C isotope
12c- stable, keeps fossil constant
14c- unstable, decays fossil
how do prokaryotes reproduce?
asexually, binary fission
Gram - bacteria
more antibiotic resistant, have outer membrane then peptidoglycan layer, then inner membrane, e.coli
what do bacteria lack?
histones to package genome, sometimes in archea
what is F factor?
fertility factor, contains genes required to make pillus
Domain of bacteria?
est. 700 000 species, diverse metabolsim, photosynthic, ana/aerobe
key innovatins in fossil record?
porkarotes, increase in O2, endosymbiosis, sex reproduction, multicell, colonization
gram + bacteria
peptidoglycan layer then membrane, tetnus
