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motive
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observation
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reaction
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stimulus
The cue or combo of cues that produces a response is called a 
, which is a thing or event that causes a specific reaction in an organ or tissue.
The appropriate answer is D. Fossils of terrestrial life forms would be found in this region. Sand and silt are typically deposited by fluvial or river processes which occur on land. Sand and silt are fine grained materials which would also suggest that the environment may possibly be a flood plain. Flood plains are located in the lower course of rivers; close to where they empty into the sea. This scenario fits with the fact that three was a drop in sea level which would expose land closest to the coast. <span />
From the given options, the following sidovery involving DNA happened first: C) Griffith learned that a chemical changed harmless cells into harmful cells.
The British medical officer named Frederick Griffith discovered DNA in 1928 while conducting experiments using Streptococcus pneumoniae bacteria and mice.
<span>He concluded that the living R bacteria had been transformed into pathogenic S bacteria by an unknown, heritable substance from the dead S cells that allowed the R cells to make capsules.</span>
Birds and mammals independently evolved four-chamber hearts
