Explain why the discovery of iron-oxidizing phototrophs has important implications for both understanding the evolution of photosynthesis and explaining the large deposits of ferric iron (Fe3+) found in ancient sediments on Earth
What will be an ideal response?
Answer: The sediments containing Fe3+ predate the existence of photosynthetic cyanobacteria that were responsible for oxygenation of the Earth. It is therefore likely these Fe3+ deposits were not formed through spontaneous (abiotic) conversion of Fe2+ and O2. Instead, it is thought anaerobic chemolithotrophs or anoxygenic phototrophs created these deposits through oxidation of Fe2+ into Fe3+.
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The female sex cells develop in paired organs in the abdomen called ________.
A) ovaries B) oocytes C) vagina D) clitoris
Pertussis has the following characteristics, except
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Which of the following samples of microbial communities would be best suited for study by microelectrode experiments?
A. Striated microbial mats B. Ten gallons of seawater C. During infection in a human patient D. Sample sorted by optical tweezers
It is common for a normal, healthy individual to carry potentially pathogenic organisms in their upper respiratory tract
Indicate whether the statement is true or false