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Chap 13 - M.O. Evol.
Microbial Evolution and Systematics
Question | Answer |
---|---|
the earth is approximately _______________ Billion years old | 4.5 |
this substance is absolutely required for life, and first appeared about 4.3 billion years ago | liquid water |
the first evidence of life began about ___________ billion years ago | 4.1 |
fossilized remains of cells can be found in rocks approx. 3.86 billion year ago which is (before/after) liquid water made it's appearance | first fossilized cells show up on the fossil record AFTER the appearance of liquid water |
in what ecosystem my have life originated in | the hypothermal systems on the ocean floor |
why would life have begun in the in the hyperthermal systems of the ocean floor | the conditions are more stable, they have a steady and abundant supply of energy |
describe the geochemistry of the hyperthermal vents | they contain important molecules including: amino acides, lipids, sugars, and nucleotides |
how might have life originated in the hyperthermal vents of the ocean floor | the vents have compartments that help conserve energy, and the geochemistry in these compartments support the production of abiotic elements that are required for life |
which element naturally occurred first? DNA orRNA | RNA was a naturally occurring element first |
why was RNA so important in Earth's early years? | RNA is part of important cofactors and molecules (ATP, NADH, and Coenzyme A), RNA can bind to small molecules and had catalytic activity |
it is believed that (RNA/DNA) catalyzed its own synthesis | it is believed that RNA catalyzed its own synthesis |
the Earliest viruses may have evolved from a _______________ genome | RNA |
eventually, _____________ replaced RNA as the catalysts of life | proteins |
_____________________ replaced RNA and became genome and template for proteins | DNA |
the earliest cells probably had ________________ for energy conservation | earliest cells probably had DNA, RNA, protein, and a membranes system for energy conservation |
what dose LUCA stand for | Last Universal Common Ancestor |
when did LUCA diverge into Archaea and Bacterial | 3.8-3.7 Billion years ago |
the earth's atmosphere at the beginning was | in the beginning, the earth's atmosphere was anoxic an any energy-generating metabolism at that time was exclusively anaerobic |
autotrophic cells obtain carbon from | autotrophs obtain carbon from CO2 |
what is nitrogen fixation | the cell's ability to use nitrogen |
cells obtain energy from Hydrogen; however, early cells may have used _______________ as an early electron acceptor | Sulphur |
early forms of ___________________ metabolism would have supported production of large amounts of organic compound | chemolithotrophic |
what is the major step that has provided the conditions needed for evolution of chemoorganotrophic metabolisms | accumulated organic material provided conditions needed for evolution of chemoorganotrophic metabolisms |
__________________ use energry from the sun to oxidize H2S, S and H2O from CO2 or simple organics | phototrophes |
at first, phototrophes were _____________ | anoxygenic |
what is cyanobacteria | bacterial that produces oxygen (oxygenic phototrophs) |
stromalites are | fossilized microbial formations |
stromalite are most closely related to modern day _____________ | cyanobacteria (phototrophic bacteria) and Chloroflexus |
after the rise of O2, allowed evolution of life to exploit __________________ | energy from O2 respirations |
explain the branded iron formations in sedimentary rock | during anoxic periods in the earth's environment reduced iron dissolved in the sediment (black lines), when there was oxygen in the environment. It blended with the iron (forming rust) and created a layer of (red line) |
how is UV Radiation harmful | UV radiation disrupts DNA and kills cells |
what is the ozone shield | molecules made of O3 that help protect the earth surface from UV Radiation. |
how is the ozone formed | when UV Radiation strikes a molecule of O2 |
what helps make the earth surface hospitable; and allows organisms to range over surface exploiting new habitats and evolving diversity | ozone |
phylogeny is | the evolutionary theory of related DNA sequences |
who came up with the universal tree of life | Carle Woese |
the universal tree of life is based on | nucleotide sequences similarity in rRNA and represents the genealogy of all life on earth |
Carl Woese established three domains, name them | Bacteria, Archaea, and Eukarya |
the root of the universal tree of life represents ______________ | the last universal common ancester, the one organism that everything on earth is spurred from |
regarding microorganisms and microbes, the tree of life shows | microorganisms and microbes have dominated most of history of life |
what is genomics | the discipline that analyzes, sequences, compares, and maps microorganisms. and it supports a three domain concept with the analysis of central cellular functional genes |
Eukaryotic cells are more similar to (Archaea/Bacteria) and are believed to have diverged from this group | Eukarya is more similar to ARCHAEA |
Which divergence is believed to have occurred first? Bacteria/Archaea, Bacteria/Eukarya, or Archaea/Eukarya | Bacteria/Archaea are believed to have diverged first |
what is the predominant hypothesis that answers the question about many genes are shared by many cells by two of the three domains | horizontal gene transfer was extensive before the primary domains have diverged |
barriers between the domainas likely evolved to maintain ______________________________ and cells slowly were sorted into primary lines of descent | genomic stability |