Chap 25 the history of life Flashcards
How are simple cells created in the beginning of earth
One the Abiotic nonliving synthesis of small organic molecules such as amino acids and nucleotides 2.the joining of these small molecules into macromolecules including proteins and nucleic acids 3.the packaging of these molecules into Protobionts droplets with membranes that maintain an internal chemistries differ from that of their surroundings 4. the origin of self replicating molecules that eventually made inheritance possible
What is hypothesize that was earths environment
Atmosphere was reducing
Are the two key properties of life
Accurate replication and metabolism
What are protobionts
Collections of abiotic produced molecules surrounded by membranes like structure
What are ribozymes
RNA which plays a central role and protein synthesis can also Carry out a number of enzyme like catalytic function
What is radiometric dating
Dating which is based on that the Decay of radioactive isotopes
Define half-life
The time required for 50% of the parent isotope to decay
What is a geologic record
A history of Earth which is divided into three eon
What Are the first two Eons
The Archean and the Proterozoic
What is the last eon
The Phanerozoic eon which encompasses most of the time that animals existed on earth
What does archaean eon in compass
The origin of earth the concentration of atmospheric oxygen begins to increase
What does the Proterozoic eon encompass
Oldest fossils of eukaryotic cells appear diverse algae and soft body invertebrate animals begin to appear
What does the Mesozoic. Encompass
Dinosaurs and reptiles
What does the Cenozoic era include
Humans primates major radiation of mammals birds and pollinating insects
What are stromatolites
Layered rocks that formed when certain prokaryotic buying thin films of sediment together
