1. Life? Flashcards
What is the protoplanetary disk?
a roataing ball of gases that was produced in the Big Bang
When did the big bang occur?
4.6 Billion years ago
How did earth form?
Gavity caused matter to condense and objects colided to form larger planets
What was the First stage of Earth?
The hadean eon
What was the hadeon era like?
- it had no free oxygen
- completly molten
- no protective atmosphere
- mostly hydrogen and helium
What caused rain and oceans during the hadeon eon?
as it was bombarded by asteroids, steam and gas was released to form the atmosphere
When did early life begin
3.8 Billion Years Ago
What was early life?
Unicellular life
What are some forms of early life?
Stromatolites like bacteria and archaea
What era did multicellular life arise?
Precambrian
What are some forms of multicellular life?
Trilobites
what was the Cambrian explosion?
an explosion where all major animal groups appeared
When did first land plants and animals appear?
the paleozoic era
when was the age of reptiles?
mesozoic era
What was the cretacous paleogener K-Pg
mass extiction
What era did humans and mammals begin emering?
Cenozoic Era
How long ago did humans first appear?
65 Million Years ago
What epoch are we in now?
Holocene Epoch
What happed during the continental drift?
land mass moved but also structure, oxygen moved leading to diversity of evolution
what does a geologic clock help us do?
visualize durations and time frames
What happened 3.8 billion years ago?
Life began
What happened 3.8 billion years ago?
Life began
What is panspermia?
The idea that life came from another place
What are the characteristics of life?
It is organized and it replicates itself
What are the four steps to life?
- Abiotic Synthesis of organic material
- formation of polymers
- Formation of protobionts
- Origin of hereditary material
what experiment probed the abiotic synthesis of organic materials?
miller-urey experiment
what is abiotic synthesis?
making things without life
what are polymers
natural substance that make up materials in living organisms
what was the formation of polymers
Amino acids connecting to create protein
what was the first polymer
clay - positivley charged with iron and zinc which polymers attracted
What ‘type’ of world in first life exist in?
RNA world
What is an RNA world ?
- can easily form abiotically
- can replicate itself
- heredity information
- has catalytic properties
What were found to be a clue to the RNA world?
Viroids
