tree of life

Question 1

what is a fossil

Answer 1

preserved remnant/impression of organism that lived in the past

Question 2

what is stromatolite

Answer 2

layered rock that results from photosynthetic prokaryotes that bind thin films of sediment together

Question 3

what is the primordial/prebiotic soup

Answer 3

hypotheical set of conditions that led to transition from abiotic–>biotic world
1) abiotic synthesis of monomers
2) polymerization of small molecules into macromolecules
3) packaging of polymers into protocells
4) origin of inheritance through transmission of self-replicating molecules

Question 4

stanley miller’s experiment

Answer 4

artificiall/spontaneous synthesis or organic matter under conditions mimicking early earth’s atmosphere+lightning

Question 5

how can polymers of amino acids form spontatneously without enzymes/ribozomes

Answer 5

• precursor molecules
• thermal energy
• catalyst

Question 6

what is a protocell

Answer 6

droplet with membranes that maintained an internal chem diff from that of its environ.
–> not living organisms (no genetic materials)

Question 7

(T/F) Natural selection can favour RNA molecules that self-replicate faster

Answer 7

T

Question 8

what does the tree of life show

Answer 8

shows evolutionary relationship between ALL organisms
–>similarities in morphology, anatomy, genetic sequences used to group

Question 9

what does the relative/absolute age of fossils inform us about the evolutionary history of organisms

Answer 9

• many fossils belong tog to species that went extinct
• some fossils resemble organisms that still exist today
• organisms can undergo very rapid morphological changes

Question 10

what is biostratigraphy

Answer 10

determination of RELATIVE age (imprecise)
–> sedimentary rocks

Question 11

what is radiometric dating

Answer 11

determination of absolute age (precise)
–> magmatic rocks

Question 12

what is faunal succession

Answer 12

specific veritcal sequence of fossilized flora and fauna that can be identifies over horizontal distances

Question 13

what are biozones

Answer 13

intervals of geological strata

Question 14

What make good biomarkers for biostratigraphy

Answer 14

species with specific ecological requirements and lived for short geological period

Question 15

what are isotopes

Answer 15

elements with same protons, different neturons
–>unstable isotope decays into daughter isotope at constant rate
–> stable isotope remains constant until fossil is discovered

Question 16

Waht does radiometric dating use

Answer 16

changes in isotope composition of:
- organisms during transition into fossils
- magmatic rocks

Question 17

what does disconinuity in fossil records show

Answer 17

important geological, ecological, evolutionary events
- changes in climate, species colonization, erosion

Question 18

what is the cambrian explosion

Answer 18

time when most major animal groups appear in fossil record
changed from soft -> hard shelled organisms

Question 19

what is the evolution of bilateral symmetry

Answer 19

• anterior sensing organs (nervous system)
• anterior predation appendages (prey capturing, feeding)
• posterior appendages for movement (swimming, crawwling, flying)

Question 20

what are adaptive radiations

Answer 20

period of evolutionary change in which groups of organisms form new species whose adaptions allow them to fill diff ecological roles in communities

Question 21

how are geological eras defined

Answer 21

massic changes in abundance/composition of fossil record AKA mass extinction

Question 22

how many mass extinctions have there been

Answer 22

5

Question 23

what are mass extinctions followed by

Answer 23

new adaptative radiations and new families/genera

Question 24

what are the key innovations in the fossil record

Answer 24

• first cells(prokaryotes)
• increase in )2 conc.
• endosymbiosis (eukaryotes)
• sexual reproduction
• multicellularity
• colonization of land

Question 25

what is LUCA

Answer 25

last universal common ancestor

Question 26

what isomer do all living organisms use

Answer 26

L optical isomers

Question 27

what are likely characteristics of LUCA

Answer 27

living near deep-dea vents, anaerobic (no O2), rich CO2, H2

Question 28

what are the 3 domains of the tree of life

Answer 28

bacteria, archaea, eukarya

Question 29

what are the characteristics of bacteria

Answer 29

• photosynthetic, aerobe/anaerobe
• highly resistant to harsh conditions
• most studied organism (cloning)

Question 30

what are the characteristics of archaea

Answer 30

• prokaryotes
• extremophiles
  mostly methanogens (use CO2+H2 to produce CH4)

Question 31

what are extremophiles

Answer 31

live in extreme environmental conditions

Question 32

what is the source of DNA polymerase for PCR

Answer 32

archaea –> heat resistance

Question 33

what are the characteristics of eukarya

Answer 33

• cytoskeleton, endomembrane system, nucleus
• gained new metabolic system
• mitochondrion, plastid

Question 34

how were eukarya evolved

Answer 34

from prokaryotes in archaea branch

Question 35

what is serial endosymbiosis

Answer 35

prokaryotic cells engulfed by an ancestral archaea cell, but not consumed

Question 36

what is the colonial hypothesis

Answer 36

colonies form through cooperation of unicellular organisms of the same species
–> cells fail to seperate
–> specialization can occur

Question 37

what is the sybiosis hypothesis

Answer 37

cells from different species establish a mutually beneficial and long-term association

Question 38

what is the burgess shale

Answer 38

paleontological site in BC with sediments with large diversity and different lifestyles