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Author Question: Proton pumps are used in various ways by members of every domain of organisms: B (Read 2948 times)

hummingbird

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on: Jun 8, 2013
Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?
A) Proton pumps must have evolved before any living organisms were present on Earth.
B) Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
C) The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism.
D) Cells of each domain evolved proton pumps independently when oceans became more acidic.
E) Proton pumps are necessary to all cell membranes.


Jones

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Reply #1 on: Jun 8, 2013
I know the answer to this :D, it's B. Don't forget to give me a thumbs up!


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hummingbird

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Reply #2 on: Jun 9, 2013
Thanks :D It was right!


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