Chapter 25.1-25.3 Origin and Diversity of Life Flashcards
When was earth formed?
4500MYA
The first 500-700 million years of earth’s history comprised what eon?
Hadean eon
How was the atmosphere of hadean’s earth?
A dynamic environment, shifting from fiery and sometimes frozen earth
What effect did low CO2 levels have on the temperature?
Earth cooled and became frozen for a period
Rodinia
A single supercontinent existed in the Southern Hemisphere during the Proterozoic eon, and broke up into smaller continents in approx. 700 MYA
Gondwana
Supercontinent made of all current southern hemisphere that contributed to Pangea
Early organisms were thought to be autotrophs with the ability to synthesize complex ____ compounds from simple ______ compounds and later use them as an energy source
Organic, Inorganic
The Hadean, Archean, and Proterozoic period makes up what
Precambrian
The Phanerozoic eon makes up what percent of earth’s life?
12%
What eon contains most of biological history of diversification of multicellular life?
Phanerozoic eon
What are the basis of all living organisms?
Organic Molecules
What is the most abundant amino acid?
Glycine
Autotropic
An organism that can produce it’s own food using light, water, carbon dioxide, or other chemicals
Heterotroph
An organism that consumes other organisms in a food chain
All oxygen molecules are a result of what?
Photosynthetic oxidation of water
What are issues with an the early RNA life theory?
No good source of ribose, challenge to form long chains of RNA nucleotide
Microfossils
Fossilized forms of microscopic life
The idea that RNA may have been the first nucleic acid to permit self-replication and the fact that ribosomes translate RNA into proteins support what?
RNA world hypothesis
For most of the history of life on earth, the only form of living organisms were what?
Single-celled
The Miller-Urey experiment demonstrated that
Organic molecules could have originated in the early atmosphere
Fossil data indicated that
life may have originated in 3.5 BYA but definitely did so by 3.2 BYA
Biomarkers
Organic molecules, which are clearly of biological origin
Beginning with a single cell in the Archean eon, life has evolve into 3 monophyletic clades called domains including?
Eubacteria, Archaea, and Eukaryotes
Endosymbiosis
Theory that proposes that eukaryotic cells evolved from a symbiosis between different species of prokaryotes
The ancient fixation of carbon happens via two main pathways:
Calvin cycle and the Krebs cycle
Living organisms incorporate ___ into their cell before any other carbon isotopes?
C12
Cyanobacteria, algae, and modern land plants use which of the following pathways for carbon fixation
calvin cycle
Which two of the following macromolecules may have composed a vesicle (or bubble) from which living cells arose?
Lipids and proteins
Multiple lines of evidence indicates that the first cells were most likely
prokaryotic
