Final

Question 1

age of earth and oldest microbial fossils

Answer 1

4.6 billion years, 3.5 billion years

Question 2

extant organisms

Answer 2

present today

Question 3

early life on earth

Answer 3

reducing
Hot
organic molecules made abiotically (lightning, UV radiation on inorganic)
RNA world

Question 4

steps in evolution of metabolism

Answer 4

evolution of porphyrins (construction of cytochromes)
development of 2nd light reaction of photosynthesis (H2O as e acceptor –> rise in O2)
oxygen as e acceptro –> evolution of aerobic organisms
formation of ozone (protection from UV)

Question 5

stromatolites

Answer 5

layered rocks from microbial mats

Question 6

endosymbiotic hypothesis

Answer 6

origin of eukaryotic membrane-bound organelles
mitochondria and chloroplasts from eukaryotic cell engulfed bacterial cell
evidence: 2 microns, binary fission, 1 circular DNA, 70S ribosomes, 2.5:1 protein lipid membrane composition, 16s rRNA

Question 7

hydrogenosomes

Answer 7

organelle found in some extant protists that use fermentation

Question 8

natural classification system

Answer 8

biological nature of organisms

Question 9

phenetic classification system

Answer 9

phenotypic characteristics

Question 10

phylogenetic/phyletic classification system

Answer 10

evolutionary relationships

Question 11

genotypic classification system

Answer 11

genetic similarities

Question 12

polyphasic classification system

Answer 12

phenotypic, phylogenetic, genotypic information

Question 13

G+C content/ratio

Answer 13

uses DNA melting temp
more G+C = more H bonds and higher melting temp
>10% difference = different base sequence

Question 14

DNA-DNA Hybridization (DDH)

Answer 14

gold standard for classification

heat dsDNA –> ddDNA, complem. stands re-associate

Question 15

average nucleotide identity (ANI)

Answer 15

measures direct sequence identity from 2 organisms

base by base comparison

Question 16

molecular phylogeny - nucleic acid + protein sequences

Answer 16

molecular chronometer
changes occur slowly
mark divergence of 2 lineages
amount of sequence difference = measure of elapsed time since divergence

Question 17

node

Answer 17

taxonomic units (species genes)

Question 18

external node

Answer 18

living organism

Question 19

length of branches

Answer 19

represents molecular changes

Question 20

core genome

Answer 20

set of genes found in all members of a species or larger group
minimal # needed to survive

Question 21

pan-genome

Answer 21

combination of all the different genes found in all strains of a given species

Question 22

cell membrane of domains

Answer 22

eukarya - ester linkages, fatty acids
bacteria - ester linkages, fatty acids
archaea - ether linkages, branched phytane hydrocarbons

Question 23

DNA dependent RNA polymerase of domains

Answer 23

eukarya - 3 but 1 makes mRNA, 10-12 subunits
bacteria - 1 w/ 4 subunits
archaea - several types w/ at lest 10 subunits

Question 24

ribosomes and protein synthesis 3 domains

Answer 24

eukarya - 80S
bacteria- 70S
archaea - 70S, shape variable

Question 25

cell walls 3 domains

Answer 25

eukarya - cellulous, chitin bacteria - peptidoglycan archaea - variable, some pseudomurein

Question 26

proteins 3 domains

Answer 26

eukarya and archaea - methionine as 1st aa | bacteria - formyl-methionine

Question 27

tRNAs 3 domains

Answer 27

archaea- contain modified bases not found in bacteria/eukarya

Question 28

DNA 3 domains

Answer 28

eukarya - number of linear chromosome in nucleus | bacteria and archaea - 1 circular molecule, smaller in archaea

Question 29

methanogenic archaea

Answer 29

methane major metabolic end product

Question 30

archaeal sulfate reducers

Answer 30

sulfate as final e acceptor

Question 31

extremely halophilic archaea

Answer 31

prefer high salt

Question 32

cell wall-less archaea

Answer 32

lack a cell wall

Question 33

extremely thermophilic S-metabolizers

Answer 33

obligate thermophiles that use sulfur

Question 34

Crenarcheota

Answer 34

phylum, resemble archaea ancestor | typically (hyper)thermophiles - optima 75 or higher

Question 35

genus Sulfolobus (phylum crenarcheaota)

Answer 35

``` thermoacidophiles temp opt. 80 pH opt 2-3 aerobes, chemoorganoheterotrophs or chemolithorophs oxidize sulfur to sulfuric acid found in hot springs, soil ```

Question 36

genus Thermoproteus (crenarcheota)

Answer 36

temp 75-100 ph 3-4 or 7 strict anaerobes chemoorganoautotrophs or chemolithautotrophs oxidize glucose with anaerobic respiration sulfur as final e acceptor in hot springs/other hot aquatic places rich in sulfur