Chapter 21 Flashcards
Organisms that produce their own food from simple raw material
Autotrophs
Time period from 600 to 542 million years ago
Ediacaran Period
Ancient remains of microscopic life
Microfossils
The largest divisions of the geological time scale
Eons
Organisms that live symbiotically inside a host cell
Endosymbionts
The time period that began 542 million years ago and lasted 291 million years
Paleozoic Era
According to this model, the chemistry of prebiotic Earth gave rise to self-replicating RNA molecules that functioned as both enzyme and substrates for their own replication
RNA World
The oldest known fossils of multicellular animals
Ediacaran Fossils
Type of fossil evidence which are rock like columns composed of many minute layers of prokaryotic cells
Stromatolites
According to this type of hypothesis, organelles such as mitochondria and chloroplasts may have originated from mutually advantageous symbiotic relationships between two prokaryotic organisms
Serial Endosymbiosis
The Earth’s beginning, 4.6 to 2.5 billion years ago
Archaeaneon
Photosynthetic autotrophs that obtain hydrogen electrons by splitting water
Cyanobacteria
How old do astrophysicists and geologists estimate Earth is?
4.6 billion years old
What hypothesis proposes that life began as a self-sustaining organized system consisting of chemical reactions between simple molecules that are enclosed within a boundary
Metabolism First Hypothesis
Divisions of the geological time scale based primarily on organisms that characterized each time period
Eras
Cells that obtain organic molecules from the environment
Heterotrophs
2500 to 542 million years ago
Proterozoic Eon
What hypothesis proposes that organic molecules formed near Earth’s surface?
Prebiotic Soup Hypothesis
The oldest subdivision of the paleozoic era
Cambrian Period
A type of protobiont formed by adding water to abiotically formed polypeptides
Microspheres
What are the six periods in the Paleozoic era?
- Cambrian
- Ordovician
- Silurian
- Devonian
- Carboniferous
- Permian
Vertebrates with four limbs
Tetrapods
The hypothesis that life developed from nonliving matter
Chemical Evolution
This time period from the Paleozoic era that much land was covered by shallow seas
Ordovician Period
A transitional form between fishes and tetrapods
Tiktaalik
Vesicle-like appendages of abiotically produced organic polymers
Protobionts
What hypothesis proposes that organic precursors formed at cracks in the ocean’s floor
Iron-Sulfur World Hypothesis
