2. Formation of earth and origin of life Flashcards
What is a protoplanetary disk
rotating cloud of dust and rocks made in the big band
When was thr protplanetory disk destroyed?
4.6 bilion years ago in the supernova
How was the sun created
the protoplanetary disk accelaterated, heated up a
How were protoplanets formed
small colliding objects that remained in the disk
How were planets formed
smaller objects collided to form larger objects
What eons are in the Precambrain super eon
Hadeon eon, archeon eon
what did earth look like during the hadeon eon
- no free oxygen, hydrogen and helium gas, molten, no protective atmpsphere
How was the atmosphere created?
it was bombarded by asteroids that released steam and gas
What did the early atmosphere consist of
ammonia, methane, nitrogen, hydrogen
what was the archaeon eon
when unicellular life arose
What was early life
stromatolites, bacteria and archea
how long ago did unicellular life arise
3 billion years ago
what eon did multicellular life arise
prechambrian, Archean
what was the first multicellular life
trilobites, hard shell animals
how long ago did multicellualr life arise
1 billion years ago
what happened in the paleozoic era
cambrian explosion and 1st land plants and animals
when did the first land plants and animals arise
the palozoic era
what ended the paleozoic era
permian extinction
What was the mesozoic era
age of reptiles and dinosours, and first mammals
what era was the age of reptiles and dinosours
mesoxoic era
when did the 1st mammals arise
mesozoic era
what were the first mammals like
rodent like -morhanucodon
what ended the mesozoic era
k-pg extinction
when was the age of mammals
cenozoic era
what are the steps to early life on earth
abiotic synthesis, formation of polymers, formation of protobionts, origin of hereditary material
what was the miller urey experiments
reproduced the condtions of early earth
what was early life made out of according to the miller urey experiment
amino acid, nucleotides, sugars, lipid, atp
what is the importance of clay
formed life since clay is positivley charged it binded with monomers to from protobionts
what are protobionts
they are a surrounded membrane that was the precursour to cells
what is a polymer
many molecules together, a protein
why do we think there was originally an RNA WORLD
easy form abiotically, can replicate itself, has hereditary info, catalytic properties
what are viroids
tiny bits of raw dna
