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1. What`are the chemical reactions involved in photosynthe~is and
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... rosebush. Scientists use nucleotide sequences to determine evolutionary relationships among organisms, to determine whether two people are related, and to identifY persons at a crime scene. The sequence of nucleotides in DNA contains information that codes for proteins. Once proteins are produced, t ...
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Precambrian body plans



Until the late 1950’s, the Precambrian era was not believed to have hosted multicellular organisms. However, with radiometric dating techniques, it has been found that fossils initially found in the Ediacara Hills in Southern Australia date back to the late Precambrian era. These fossils are body impressions of organisms shaped like disks, fronds and some with ribbon patterns that were most likely tentacles.These are the earliest multicellular organisms in Earth’s history, despite the fact that unicellularity had been around for a long time before that. The requirements for multicellularity were embedded in the genes of some of these cells, specifically choanoflagellates. These are thought to be the precursors for all multicellular organisms. They are highly related to sponges (Porifera), which are the simplest multicellular organisms.In order to understand the transition to multicellularity during the Precambrian, it is important to look at the requirements for multicellularity—both biological and environmental.
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