Unit 6 Flashcards
Great oxidation event
created conditions for widespread aerobic respiration, eukaryotes and transformed the planet
-led to aerobic respiration then aerobic respiration in eukaryotes
Stromatolites
fossilized microbes (cyanobacteria)
Anoxygenic photosynthesis
does not produce O2
produces high energy molecule, elemental sulfur, H2O
random mutations that turned out to be beneficial=evolved to oxygenic photosynthesis
Photosynthesis in bacteria
can produce the carbohydrate formeldahyde
Increased O2 levels caused
molecules that were once uncommon became more common, produced sulfur acid which caused chemical weathering of rocks and leaching of minerals necessary for life into rivers and oceans
Aerobic respiration
requires O2
-much more efficient than anaerobic respiration because it produces more ATP
-random mutations made this happen and proven to be advantage
Photosynthetic bacteria
-changed earth through oxygenic photosynthesis
-initial oxygenation of the biosphere, production of organic carbon, increased nutrient availability to other organisms
Bacteria and archaea
-changed earth through aerobic cellular respiration
Nitrogen fixing bacteria
-changed earth through nitrogen fixation (conversion of N2 to ammonia)
-nitrogen availability to other organisms in the biosphere
Nitrogen fixation
-invented and performed by bacteria that converts unusable nitrogen into a form that is useable by living organisms
-requires minerals, made more available that O2 increase made through weathering, increased nitrogen fixation
-can happen biologically, industrial, lightning
Bacteria fixation
covering of nitrogen gas to ammonia, occurs in roots of some plants
-ammonia enters soil, goes through nitrification, converts to nitrites, converts to nitrates (done by microbes/bacteria)
-takes place in soil with abundant oxygen
Denitrification
performed by bacteria in habitats with low oxygen levels, result in conversion of nitrates back into nitrogen gas
-can also result in release of nitrous oxide (green house gas)
Causes of N2O production
-fertilizers
-denitrifying microbes are unable to fully convert nitrate to N2, N2O gas is released from the soil before it can be converted into N2
-decomposition of human waste produces ammonium
Global warming
-N2O increasing in atmosphere, related to human activities
-fertilizers increased production of N2O
-greenhouse gases absorb infrared radiation and redirect heat energy towards earth
-N2O more powerful than CO2
Traits that helped aquatic algae transform into land plants
-drying out and protection from solar radiation
-reproduction without water
-structural support on land
-moving materials against gravity
Cuticle
-benefit=structure that allowed for water loss prevention and UV protection
-drawback=what about gas exchange, cuticle evolves
Stoma
-hole that can open and close in cuticle, CO2 goes inside, O2 goes outside, evolved to help drawback of cuticle
Phloem
transports sugars (food)
2 way tube, goes up and down
Xylem
transports water
1 way from roots to leaves
Plant plumbing
having plumbing system allowed plants to get large
more size=more carbon storing in its tissues=more CO2 being removed from atmosphere=more oxygen produced
Plant innovations impact on earths atmosphere
massive increase in oxygen production
massive decrease in carbon dioxide
changes in global temperature
evolution of giant insects
Spiracles
where gas exchange occurs in giant insects
increased O2, increased respiration and metabolic rates
Spores
-part of plant reproduction
-one celled haploid reproductive units that aid in dispersal to new locations
Pollination
movement of pollen (male gametophyte) to plant female structure
-results in fertilization
Gymnosperms
wind moves pollen
seeds, no fruits
Angiosperms
animals move pollen
fruits with seeds
Seeds
baby plants (product of fertilization) inside a protective sheath (seed coat)