Bio 4H Chapter 25 (exam 3)

fossil

any record of a record of a living organism preserved in rock

fossilization more likely

• hard parts (teeth bone shell)

• lives marine/lake environment

• numerous (#)

• widespread (vast)

stratigraphy

relatie age of fossil determined from layer (strata) where rock is found (bottom oldest top newest)

radiometric dating

absolute age of fossil determined from radioactive decay of particles in rock (fixed carbon amount)

Precambrian life

• prokaryotic cells growing mounds (similar stromatolites)

• prokaryotic smaller no nucleus

• eukaryotic larger, nucleus 

• o2 found in air

  • banded iron deposit/iron oxide (rust)

  • origin photosynthetic bacteria

• 1st eukaryotes fossils 

Paleozoic era

• trilobites

• age of fishs

• plant invade land

• 1st insect, mammal like reptile/reptile

mesozoic era

• age dinasaurs

• cone bearing plants predominant

• first flowering plants/mammals

cenozoic era

• adaptive ration of mammals, birds, insects, flowering plants

biogeography

study of spatial distribution of species

continental drift

plates of earth’s crust move over time

Pangea 

all today’s continents joined 1 supercontinent, all earth/land

extinction

every member 1 species dies and species cease to exist

mass extinction

many species extinct around same time (same 1000 yrs)

end cretaceous mass excitations 

• volcanic activity (debris in air block sunlight, no sunlight plant die, no plant animal die)

• meteor impact