Photosynthesis • Oxygen binds readily with iron to form iron oxide, a dense compound that settles through
water to form sediments. Early oceans had large quantities of iron dissolved in their waters.
Explain how the composition of Earth's systems would change as more oxygen became
available due to photosynthetic cyanobacteria. Use evidence from your model to support
your explanation

Explain light independent reactions

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time