ch 15 Flashcards
how old is earth?
4.6 billion years
Primitive soup
cooled oceans became
solution of organic molecules (can duplicate
this in laboratory)
What can stimulate production of amino acids and act as an enzyme?
RNA
Protocells
self-replicating system enclosed in a membrane (created in a lab)
4 points of the history of life
- The abiotic (nonliving) synthesis of small organic
molecules, such as amino acids and nitrogenous
bases - Small molecules bond to produce larger
molecules such as proteins and nucleic acids - Protocells – molecules aggregated and
surrounded by lipids that separated internal
environment from outside - Ability of some molecules to self-replicate
What type of heterotrophs were first?
anaerobic, fed on each other
what led to autotrophs?
competition and natural selection
what built up the o2 level in the atmosphere?
autotrophs
when did multicellular organisms arise?
2.1 billion years ago
endosymbiotic theory
mitochondria and plastids were once prokaryotic cells
what led to the rise and fall of various species?
changes in earth
when was the movement to land and who was first?
500 million years ago, plants
Period with first vascular plants
Silurian
Period with first land plants
ordovician
Period with tremendous diversity
Paleocene
