<em>Answer </em><em>is </em><em>- </em><em>D </em><em>the electron transport </em><em>chain </em><em>combined </em><em>with</em><em> </em><em>chemiosmosis </em>
The precambrian era makes up about 90% of the earths history, but there was little to no living organisms at the time other than microscopic ones. The first eukaryotes were found in the cambrian period after the precambrian period, not only that but at the end of the precambrian era in the Proterozoic era there was a mass extinction of about 70-80% of all living organisms
I'm pretty sure that was <span>Oswald Avery.</span>
The correct answer is: c. An operon is a region of DNA that codes for a series of functionally related genes under the control of the same promoter.
Operons contain cluster of genes that are transcribed together into mRNA or are not expressed at all. Formed mRNA undergos splicing to create monocistronic mRNAs so that can be translated separately. Operons are more often found in prokaryotic cells but it can appear in eukaryotic cells and in viruses.
<span>Well active transport absolutely moves substances against their concentration gradient (answer C), although I dislike how the other answers could probably be argued for. This seems to be a case of pick the "best" answer</span>
